COLORADO
VISION SCREENING
GUIDELINES
FOR
INFANTS AND TODDLERS
Prepared by
Paula B. Hudson, Ph.D., C.C.C.
Speech and Language Services Consultant
Developmental Evaluation Clinics Coordinator
Health Care Program for Children with Special Health Care Needs (HCP)
Colorado Department of Public Health and Environment
Tanni Anthony, Ed.S.
Colorado Department of Education
State Consultant on Visual Impairment
J. Greeley, M.A.
Teacher of the Blind
Anchor Center
LuAnn Humphreys, M.A.
John f. Kennedy Child Development Center
August 2002
COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
TABLE OF CONTENTS
Introduction .................................................................................................. iv
Policy Statement from American Academy of Ophthalmology .................... vi
Chapter 1 - Guidelines
Recommended Practices for Vision Screening of Children
Ages Birth to Five Years........................................................................ 1
Who Should be Screened and When? ........................................... 1
What are the Risk Factors for Visual Impairment? ......................... 2
Who Should Conduct the Screening? ............................................. 2
What is the Role of the Vision Screener? ....................................... 3
How Should the Screening be Conducted ...................................... 3
Possible Outcomes of the Screening Process ................................ 4
Qualifications and Training of Screeners ........................................ 5
Vision Screening Instruments and Techniques............................... 8
Screening Flow Chart ..................................................................... 8
General Procedures ........................................................................ 8
Establishing Rapport with Child ................................................ 8
Explaining Importance and Procedures to Parents/Caregivers 9
Preparation for Testing ............................................................. 9
General History ........................................................................10
Possible Signs of Visual Impairment in Infants/Toddlers .........11
Visual Screening Procedures .........................................................12
Appearance of Eyes ................................................................12
Pupillary Response ..................................................................13
Cover/Uncover Test .................................................................14
Fixation ....................................................................................15
Follow Skills .............................................................................16
Corneal Reflection Test ...........................................................17
Photo Refraction Test: Photo Screener ........................................17
Questions to Consider When Screening the Vision of
Children Who Are Difficult to Screen .............................................19
Referral and Follow-up Procedures ...............................................20
Universal Vision Screening Flow Chart ..........................................22
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Chapter 2 - Forms
Colorado Vision Screening for Infants and Toddlers Form ..................24
How to Prepare for the Eye Examination Appointment ........................26
Screening Permission Form .................................................................27
Letters to Parent
Your Child Passed the Screening ..................................................28
Your Child Should See the PCP ....................................................29
Referral Letter to PCP ..........................................................................30
Release of Information .........................................................................31
Parent Feedback to the Colorado Vision Screening Program .............32
Doctor Recruitment Letter ....................................................................33
Questionnaire of Eye Care Specialists .................................................34
Chapter 3 - Cover - Uncover Test
Observable Deviations .........................................................................35
Test III - Alternate Cover-Uncover Test ...............................................36
Illustrated Instructions for the Test III - Alternate Cover-Uncover Test 37
Chapter 4 - Observation of Vision Problems
Appearance ..........................................................................................38
Behavior ...............................................................................................38
Complaints (About) ..............................................................................39
Chapter 5 - Normal Vision Develop
How Does Normal Vision Develop .......................................................40
Sequence of Development of Vision ....................................................40
Developmental Sequence of Functional Visual Abilities:
Birth to Three Years .......................................................................41
Basic Eye Responses ..............................................................41
Basic Visual Motor Responses ................................................42
Basic Visual Discrimination Responses...................................43
Normal Visual Development by Irene Toper, M.Ed. .............................44
What Vision Problems Cound be Detected by Screening? ..................45
Chapter 6 - Types of Vision Problems a Child Can Have
Poor Visual Acuity ................................................................................47
Loss of Visual Field ..............................................................................47
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Poor Stereopsis (Depth Perception) ....................................................48
Poor Color Vision .................................................................................48
Poor Visual Processing ........................................................................48
What Conditions Interfere with Normal Visual Development?
Genetic Syndromes .......................................................................48
Prenatal Illness in Mother ..............................................................49
Perinatal Conditions .......................................................................49
Refractive Errors ............................................................................49
Muscle Imbalance ..........................................................................49
Nystagmus .....................................................................................50
Cataracts........................................................................................50
Retinal Detachment .......................................................................51
Retinopathy of Prematurity (ROP) .................................................51
Retinoblastoma ..............................................................................51
Chapter 7 - Glossary of Terms Associated with Vision ..............................52
Certificate of Training .................................................................................60
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INTRODUCTION
The goal of vision screening is the prevention of serious vision problems
through early detection and referral for treatment. Colorado, along with many
other states, has instituted and published standards for older children (three
years through school ages) which are readily available, but there are no
standard procedures instituted statewide for the screening of vision in children
birth to 36 months. In fact, many children may not have their vision screened
before the year they enter kindergarten.
The absence of early universal screening seems to be a major deficit in the
health care provision for young children. It seems doubly concerning when
one knows that vision is the primary learning modality of most children, yet
may be the last developmental area to be examined. The first three years of a
child’s life make up a critical period for the development of visual skill.
Refractive errors are the most common visual disorders of children, occurring
in 20% by 16 years of age. Amblyopia ("lazy eye") develops in 2% to 4% of
children. The risk of developing amblyopia is greatest during the first 2 to 3
years of life, but the potential for its development exists until visual
development is complete at 9 years of age. Left untreated, amblyopia may
lead to irreversible visual deficits. Strabismus occurs in 2% of children and is
one of the primary causes of amblyopia. Other eye diseases occurring during
infancy and childhood include cataracts (1 per 1000 live births) and
retinopathy of prematurity. The early detection of vision problems and
disorders reduces the long term effects and allows children the opportunity to
develop educationally, emotionally and socially (Atkinson, J., Braddock, OJ,
Durden, K., et. Al., Screening for refractive errors in six to nine month old
infants by photorefraction. Brit. J. Ophthalmol. 1984; 68: 105-112).
Over the years, the importance of early identification of children with visual
impairments has become increasingly apparent. In 1986, the United States
Congress passed Public Law 99457 (to become reauthorized as Public Law
102-119, The Individuals with Disabilities Education Act -IDEA). This law
requires that children with disabilities, including vision problems, receive a free
and appropriate public education from the time they are three until they are 21
years of age. IDEA also provides for certain types of services for children birth
to three years of age. One of the services is to find infants and toddlers with
disabling conditions, including visual impairment.
The American Academy of Family Physicians and U.S. Preventative Task
force support that all children should have testing for amblyopia and
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strabismus before entering school, preferably at 3 to 4 years of age. The
American Academy of Ophthalmology (MO), American Academy of Pediatrics
(MP), American Association for Pediatric Ophthalmology and Strabismus
(MPOS), and American Optometric Association (AOA) suggest that eye and
vision screening should be performed at birth and at approximately 6 months,
three years and five years of age. The Canadian Task force on the Periodic
Health Examination suggest that an eye examination and the cover/uncover
test be performed on children during the first week of life and at 2 to 4 weeks,
2 months, and 2 to 3 and 5 to 6 years of age.
Through the effective use of preschool vision screening, young children with
eye problems can be referred to the proper sources for examination,
diagnosis and treatment. Early detection and correction can save a child from
a lifetime of visual impairment.
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COLORADO VISION SCREENING GUIDELINES
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POLICY STATEMENT from American Academy of Ophthalmology
Vision Screening for Infants and Children
Policy
The American Academy of Ophthalmology
recommends timely vision and eye health
screening for the detection and early treatment
of eye problems in America’s children. This
includes institution of vision screening during the
preschool years. Screening by lay people mainly
detects reduced vision in one or both eyes from
errors of refraction, amblyopia, and strabismus.
Other eye health screening is carried out during
infancy, and depends in a large part on parental
awareness as well as on detection of eye
disease by primary care physicians. Very early
detection of treatable eye disease in infancy and
childhood can have far reaching implications for
vision and, in some cases, for general health.
Background
Good vision is essential for children as they
develop physically and move through the
process of education. The visual system in the
young child is immature and requires equal input
from both eyes for brain vision centers to
develop normally. If an eye is not used properly,
visual acuity declines in that eye resulting in
abnormal binocular function and absence of
stereoscopic depth perception. Early detection
of defective vision provides the best opportunity
for effective, inexpensive treatment.
Vision screening programs permit widespread
testing in preschool and early school-age
children.
Many school systems have regular vision
screening programs that are carried out by
volunteer professional screeners, school nurses,
and/or lay persons. Screening can be done
quickly, accurately, and with minimum expense.
The screener should not have a vested interest
in the screening outcome. While screening can
identify many visual problems, it is not a truly
diagnostic procedure and will not necessarily
detect all problems or identify their causes.
School vision screening has a degree of
inaccuracy that is inherent in any screening
process. The inaccuracy should be accepted as
unavoidable.
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Among those conditions which can be
detected in children by vision screening using an
acuity chart beginning in the preschool years
are: reduced vision in one or both eyes from
amblyopia, uncorrected refractive errors or other
eye defects and, in most cases, misalignment of
the eyes (called strabismus).
Amblyopia is poor vision in an otherwise
normal appearing eye. Two common causes
are crossed eyes and a difference in the
refractive error between the two eyes. If
untreated, amblyopia can cause irreversible
visual loss. The best time for treatment is in
the preschool years. Effective treatment after
the child is 8 or 9 years of age is rarely
achieved.
Strabismus is misalignment of the eyes
whether the eye turns in, out, up or down. If
the same eye is habitually misaligned,
amblyopia may develop in that eye. Early
detection of amblyopia resulting from
strabismus, followed up by treatment with
patching and any necessary glasses, can be
effective in restoring vision. The eyes can be
aligned in some cases with glasses and in
others with surgery, but neither of these
treatment techniques replaces the need for
patching when it is indicated.
Refractive errors cause decreased vision,
visual discomfort (“eye strain”), and/or
amblyopia.
The most common form,
nearsightedness (poor distance vision), is
usually seen in school-age children and is
treated effectively, in most cases, with
glasses. Farsightedness (poor near vision)
can cause problems in seeing close work
and is also treated with glasses.
Astigmatism (imperfect curvature of the front
surfaces of the eye) also requires corrective
eye glasses if it produces blurred vision or
discomfort. Uncorrected refractive errors can
cause amblyopia in some case.
Vision screening can only detect a child’s visual
problem. An effective screening program should
have some mechanism for follow-up treatment
for parents to access.
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COLORADO VISION SCREENING GUIDELINES
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Vision Screening for Infants and Children
Page 2
Recommendations
The American Academy of Ophthalmology
recommends that infants and children be
screened as follows:
1.
A pediatrician or family physician should
examine a newborn’s eyes for general
eye health in the nursery.
An
ophthalmologist should be asked to
examine all high risk infants, i.e., those
at risk to develop retinopathy of
prematurity (ROP), those with a family
history of retinoblastoma, congenital
glaucoma, cataracts, or diseases
associated with eye problems, or when
any opacity of the ocular media or
nystagmus
(purposeless
rhythmic
movement of the eyes) is seen.
Examination of these infants should be
repeated at appropriate intervals. No
infant is too young for an eye
examination by an ophthalmologist. An
ophthalmological examination should be
performed whenever questions arise
about the eye health of a child at any
age.
2.
All infants by six months of age should
be screened for ocular health by a
pediatrician, family physician or an
ophthalmologist.
3.
Each child at age approximately 3 ½
should be screened for eye health by a
pediatrician, family physician, or an
ophthalmologist. Emphasis should be
placed on testing of visual acuity.
4.
Children at age 5 years should have
vision
evaluated
and
alignment
assessed by a pediatrician, family
physician, or an ophthalmologist. Those
children who fail either test should be
examined by an ophthalmologist.
5.
Further screening examinations should
be done at routine school checks or after
the appearance of symptoms. Routine
professional eye examination of the
normal child has no medical benefit.
Approved by: American Association for Pediatric
Ophthalmology and Strabismus
May 1991
American Academy of
Ophthalmology
Board of Directors
June, 1991
Revised and
Approved by: American Association for Pediatric
Ophthalmology and Strabismus
September, 1996
American Academy of
Ophthalmology
Board of Trustees
September, 1996
Most serious ocular conditions, which can be
found at screening and are treatable, are
identified in the preschool years. Many of these
conditions are associated with a positive family
history. Screening emphasis should, therefore,
be directed to at risk infants and to those
children in the early preschool years.
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CHAPTER 1 - GUIDELINES
RECOMMENDED PRACTICES FOR VISION SCREENING
OF CHILDREN AGES BIRTH TO FIVE YEARS
ALL CHILDREN ARE TESTABLE!
This document was written to provide guidelines for the development and
refinement of vision screening practices of young children, including those
who are preverbal or nonverbal.
WHO SHOULD BE SCREENED AND WHEN?
All children should be screened for possible vision problems, especially those
under the age of three with a suspected or identified risk factor, regardless of
severity of that risk factor.
The American Academy of Ophthalmology and the Canadian
Ophthalmological Society recommend that a newborn's eyes be examined for
general eye health and major anomalies by a pediatrician or family physician
in the nursery. A family physician, pediatrician or ophthalmologist should
screen all infants by six months of age for eye health and all preschoolers
(three to four years of age) for visual acuity. Screening by the professional
should occur earlier whenever parents/caregivers/teachers suspect an eye or
vision problem or if the child is at high risk for such problems.
Note: In the state of Colorado, Public health Nurses involved in providing
care for newborns, infants and young children in clinic and home settings are
trained and expected to include the child’s history and physical examination
assessment of the eyes and vision. A history constitutes approximately 80% of
the assessment and includes an interview with questions regarding family,
prenatal, peri-natal, developmental history as well as a history of all health
problems. Eyes and vision concerns of parents should be specifically
addressed and explored. In the physical exam, the nurse does an assessment
which should include noting visual response when following a toy, light or
finger; checking extra ocular movements; an external eye exam including size,
shape symmetry, brows, lashes, lids, sclerae, conjunctivae, irises, and pupils;
checking the red reflex; noting direct and consensual pupillary responses to
light; and noting the appearance of eyes being straight. If any suspicion of
visual problem, risk, or eye muscle imbalance come to light during the history
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taking or physical examination, the nurses add other assessment including
cover-uncover testing and noting equality of sclerae seen between inner
canthus and iris. The nurse should know that some muscle imbalance may
exist until about 6 months of age but that any persistent or severe symptom
should be referred at any age. Amblyopia is considered a major concern
which means that any difference between and early and late diagnosis may
mean the difference between normal function and a significant disability.
WHAT ARE RISK FACTORS FOR VISUAL IMPAIRMENT?
•
Any child whose parent/caregiver/teacher has concerns regarding visual
development.
•
Any child who has the following medical conditions and/or diagnoses:

Family history of amblyopia, strabismus, and any congenital
ocular abnormality

Prenatal virus

Prenatal exposure to drugs

Prematurity and/or low birth weight

Cerebral Palsy

Hearing loss

Syndromes of any kind

Traumatic Brain Injury

Postnatal infection

Receives an ongoing medication such as an anticonvulsant
WHO SHOULD CONDUCT THE SCREENING?
The initial screening should be conducted by a physician whenever possible.
When this is not initially feasible, screening should be carried out by trained
personnel, as determined at the local level, working with a
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parent/caregiver/teacher who is familiar with the child. When questions arise,
the screener should then request assistance from a recognized team of
qualified individuals which includes appropriate medical and educational
personnel.
WHAT IS THE ROLE OF THE VISION SCREENER?
•
To document visual performance during the screening.
•
To identify potential problems in visual development.
•
To communicate the results of the screening to the family and appropriate
professionals.
•
To ensure the continuation of the screening process, if needed, and make
referrals.
•
To follow up on all referrals.
HOW SHOULD THE SCREENING BE CONDUCTED?
To begin:

Establish a rapport with the child.

Position the child appropriately.

Allow for a variety of communication methods.

Provide extra response time for the child.

Use methods of observation that follow the child's lead and, if
necessary, observe within the child's home or school
environment.

Include test items that are familiar and/or interesting to the child.

Screen with a team approach (e.g. parent/caregiver/teacher).

Provide opportunity for rescreening whenever results are
inconclusive due to illness, fatigue, or other confounding factors.
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To test:

Review the medical history of the child and his/her family, noting
high risk populations, current use of medications, and significant
medical findings.

Elicit parent/caregiver observation of the child in different natural
environments. Encourage the parent/caregiver/teacher or
someone who knows the child well to note any concerns about
the child's vision.

Use screening tools that address:
- appearance of the child’s eyes.
- pupillary response to a light source
- oculomotor skills such as fixation,
- visual pursuit and convergence.
- visual field
- functional/clinical visual acuity (near and distance); also
noting any significant difference between the acuity of each of
the eyes.
POSSIBLE OUTCOMES OF THE SCREENING PROCESS:
Outcome One: No problems are observed and there are no concerns of the
parent/caregiver or screener. The child passes the screening and is screened
again at the next recommended age.
Outcome Two: One or more of the high risk conditions have been identified,
but there are no observable problems with visual performance. On the day of
the screening, information should be given to the family and the local service
provider about a) high risk indicators of visual problems; b) how to observe
visual performance; and c) resources to contact, if vision problems are
observed at a later date.
Outcome Three: A prompt referral to the child's primary care physician and a
suggested referral to an eye care specialist should be made if:
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(a)
The child has an observable eye condition such as excessive
tearing, redness, eye deviation or misalignment, nystagmus which
is jerky repetitive eye movements) drooping eye lid, cloudiness of
the pupil or cornea, and so on.
(b)
The child has observable difficulty with one or more behavioral
items (i.e. visual behavior and acuity) on the screening tool.
(c)
The parent/caregiver/teacher or screener still has questions and
the team is unable to make a determination of whether or not the
child is having visual difficulty. This includes any evidence of a
significant difference in acuity of the two eyes (risk of amblyopia),
abnormal head tilt, squinting of eyes, closing or covering of one
eye, and not wanting to wear prescribed glasses.
Remember: This does not mean that the child is untestable. It
does mean that the screener is responsible for referring the child
on to someone else for more in-depth evaluation.
Special Note:
Screening procedures for young children should use family-centered
practices, i.e. communicating in a language that the family understands;
informing families about the purpose, procedures, and results of the screening
process; and gathering information from families in a simple and respectful
way.
Young children can be difficult to test. Local teams are knowledgeable about
the available resources in their area and should send families to the local
professional who are best qualified to handle referrals from the screening.
This document was developed by the XVII International preschool Seminar participants in April of
1995 (Boston, MA) and revised at the XVIII International Preschool Seminar in May of 1997 (Estes
Park, CO). Permission is granted to copy and disseminate this document.
QUALIFICATIONS AND TRAINING OF SCREENERS
Note: As stated in the Introduction, the short term goal of this screening
program is to introduce and standardize a screening approach and new
technology (specifically the photoscreener) which can be easily used on all
children in the state of Colorado between the ages of 6 months and 3 years.
The screening program general training would be initiated within the area of
Public Health because a large segment of the population could be tested and
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data collected as to the efficacy of such a program. The long term goal of the
screening program is to standardize screening procedures, testing
protocols, products and follow-up procedures and make them available to all
agencies public and private that serve children from the ages of 6 months to 3
years. By using the photoscreener technology it is hoped that volunteers could
be trained to do basic level screenings which would allow us to identify many
more children in the state at risk for vision disorders. This would include public
schools, child find, Part C as well as private practitioners.
All persons assisting with the vision screening should be knowledgeable of all
facets of the screening project, such as training requirements, screening
methods, standards, referral policies and procedures.
Individuals who perform vision screenings for the Department of Public Health
and Environment will be trained by a designated vision specialist through the
Colorado Department of Public Health and Environment: Health Care program
for Children with Special Needs( HCP) or designated trainers. The most
important qualifications for a volunteer are the abilities to relate well to
children and families, feel at ease working with them and to be a careful
observer.
In order to qualify for a certificate from the Colorado Department of Health and
Environment/ Health Care Program for Children with Special Needs, full time
attendance at an annual training course and/or satisfactory evidence of the
knowledge and skills required to provide screening services is required. A
reasonable amount of free time to perform the screening activities when
needed and/or requested by the local health department is expected of the
volunteer who accepts training. The training course is usually limited to 20
persons so that individual attention may be paid to each trainee during
practice.
Because of the complexity of interpretations of the photo vision screening
products (a complete description of the photoscreener is on page 16), it is
recommended that the manual be consulted with the collaboration of a
specifically designated on-site person (such as the Public Health Nurse) in
making any pass/fail decisions. All screening failures must be referred for
professional evaluations and treatment. Paraprofessionals, technicians,
nurses aides, and volunteers can be trained and supervised to assist in the
photo-vision screening process.
A three to four hour training session for screening vision in children will
include:
•
Registration and distribution of reference manuals.
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•
•
General information:
•
the purpose of the screening.
•
time factors involved in a vision screening.
•
normal visual development.
•
high risk factors for visual problems.
•
possible visual problems in young children.
•
recommended practices for vision screening of children ages birth to
five years.
Screening methods
•
general - including rapport building, family-centered practice.
•
observation screening for signs of eye and vision problems.
•
demonstration of screening tools - pupillary response, cover/uncover
•
test, fixation, follow skills, and photo screener.
•
special considerations: difficult-to-screen children.
•
conferencing with parents.
•
Referral and follow-up procedures.
•
Completing necessary paperwork.
•
Supervised practice session. Trainees screen each other and young
children (if available). Trainees select and arrange a screening area in
preparation for the practice.
•
Presentation of Certificates to those who meet requirements.
•
Annual refresher certification is usually limited to two hours. This is
provided to "veteran screeners” who simply need an up-date on current
standards and/or equipment demonstrations. The Colorado Department of
Public Health and Environment may use video comparison and distance
learning for reevaluation of screeners.
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Plans for training should always include the coordinated efforts of
representatives of the local health department, local education agency and
involved volunteer groups so that the screening process becomes a
community interagency effort.
VISION SCREENING INSTRUMENTS AND TECHNIQUES
This is a screening and should only take about 20 minutes to complete.
Screeners are looking for indications of visual problems and not diagnosing
them. Any of the specified signs warrant a referral to the family's Primary
Care Physician (PCP) and a suggested referral to an optometrist or
ophthalmologist.
SCREENING FLOW CHART
SCREEN
CHILDREN 6-36
MONTHS

CONFERENCE WITH PARENTS: RESULTS, RESOURCES

INFORMATION
DISSEMINATION:
EYE CARE,
HEALTH, SAFETY,
RECHECK
SCHEDULE
RESOURCES;
EPSDT,
PASS
CHILD FIND, EYE
CARE SPECIALIST


PASS FAIL
REFER TO:
PCP
EYE CARE
SPECIALIST
RESOURCES
INFORMATION

QUESTIONABLE

RESULTS
TO PCP

RECHECK
FAIL
REFER TO
PCP
FOLLOW-UP
MAILING,
PHONE CALL
RECORD OF SCREEN
TO PARENT AND PCP
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GENERAL PROCEDURES
Building a rapport with the child:
•
Make every effort to put child at ease: screen at a time that is usually
good for the child; do not keep child waiting; follow the families rhythm,
allowing time for toileting, nursing, or breaks as needed
•
Greet the child and talk before requesting specific performances
•
Observe and respond to the child's behavior, e.g. notice if child turns
away because of overstimulation.
•
Refer to the child and parent by name.
•
Allow the child to sit on his or her parent's or Caregiver's lap for comfort
and security, if necessary.
Explaining Purpose and Procedures of Screening Process to
Parents/Caregivers:
Discuss with families or caregivers that children do not know how they should
see. Often children cannot tell us how they do see. During the early years of
life, children will learn to use their eyes. Thus, it is extremely important to
screen children as early as possible to detect any vision problems. This
allows possible treatment to begin quickly. It also allows for the initiation of
early intervention if necessary.
“Today, we will look carefully at your child's eyes, and watch your child play
and look around. However, vision problems are not always obvious. Most
vision problems are not painful. Even after looking at children's eyes, and
watching how they act, it still may be hard to figure out if they have vision
problems.
You know your child best. Please share your important information about your
child's and your family's health. Can you think about any family members who
have had vision problems? Then, we will look at your child's eyes, and if your
child is old enough ask your child some questions. Please let us know if your
child's behavior during the screening is typical for your child.”
Using all of the information gathered, we may say, "At the present time, your
child's vision seems to be developing on schedule" - or we may suggest to the
family or caregiver that they closely watch their child's visual performance, or
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
take their child to their primary care physician for a professional exam or a
referral to a vision specialist.
Preparation for Testing
1. Make sure that the room used for screening is quiet, with no distractions
(like pictures, toys, and other children), and is well-lighted and free from
glare, with available window coverings so that it can be darkened.
2. Children who wear glasses should be screened with their glasses on
through all procedures except when using the photo refraction camera.
Children should NOT wear glasses when being screened with the
camera.
3. For many of the screenings, an occluder will be needed (something to
cover the eye that is not being tested). Any of a number of easily
available items may be used; paper cups, paper patches, index cards, or
the palm of the child's own hand. If you use any paper materials, throw
each piece of paper material away after using it on one child. If children
use their hands, be sure that they are not peeking through their fingers.
Shapes cut out of construction paper can be used and then given to the
child to keep.
4. Watch carefully to be sure that the child is not peeking, tilting the head,
not squinting. If at all possible, have someone stay next to the child and
watch closely.
5. Look at the child closely for signs of eye infections. If the eye is red,
swollen or crusty, the child needs to be referred for medical attention to
the PCP. Do not screen the child's vision until the eye problem has been
treated.
6. Photo copy parent letter (appendix), screening protocol(appendix) and
photo of the child's eyes for the parent, and your records. Return the
originals to the local coordinator.
General History
Find out if the child meets any of the high risk conditions for visual problems.
This can be done by asking the parent the following questions:
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
•
Do you have any concerns about your child’s general health or specific
vision issues?
•
Has your child's hearing ever been tested? If so, what were the results?
Do you have any concerns about your child's hearing?
•
Has your child ever had any illness or injuries?
•
Has your child ever been diagnosed as having cerebral palsy?
•
Has your child been exposed to any prenatal infections?
•
Has your child ever been diagnosed as having any syndrome?
•
Was your child born more than six weeks before the expected due date?
Did your baby weigh less than 3 pounds and 5 ounces at birth?
•
•
Has your baby been prenatally exposed to drugs or alcohol?
Is there a family history of vision problems (e.g. medical conditions such
as cataracts or glasses for near or farsightedness?)
•
Is your child taking any medications now?
If the parent answers YES to any of the above questions, or indicates
that the child has a hearing loss, and there are no observable problems
with visual performance, provide the family and local service provider
with information about high risk indicators of visual problems; how to
observe visual performance; and resources to contact, if vision
problems are observed at a later date. Refer the child to primary care
physician by the time the child reaches three years of age.
If the parent answers YES to any of the above questions, or indicates
that the child has a hearing loss, and there are observable problems
with visual performance, refer immediately to the primary care
physician.
Possible signs of Visual lmpairment in Infants/Toddlers
Observe the child for any of the possible signs of visual impairments. If you
have no opportunity to observe any of the signs, ask the parent/caregiver if
they've noticed any.
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
•
Does the child have a history of watery/red/inflamed eyes, or red/
encrusted/watery/swollen eyelids?
•
Does the child stumble or hesitate to move?
•
Does the child hold toys up close to the his or her face, or is the child
inattentive to toys unless the toy has a sound cue?
•
Does the child assume postures such as bending his or her head down,
or holding his or her head in a specific way to look at objects or people?
•
Does the child visually miss objects in a certain location of his or her
visual field?
•
Does the baby have trouble following objects with his or her eyes?
•
Does the child squint/frown when focusing?
•
Do the child's eyes not work together when the baby looks at something?
•
Does the baby seem visually unaware of his or her surroundings?
•
Does the baby seem overly sensitive to light? Are the child's eyes visibly
out of alignment?
Results
After the screening remember to ask the parent/caregiver if the behavior
of the child during the screening was typical for that child.
If any of the screening questions were answered YES, refer the child to
the primary care physician with the suggestion of a referral to an eye
care specialist. Also find out and record in detail what concerns the
parent/caregiver is having about the child's vision.
...............................
Visual Screening Procedures
Appearance of eyes
Look for the following deviations of the child's eyes:
•
Are the eyes unequal or not side by side?
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
•
Is cloudiness seen through the pupil (evidence of a cataract)?
•
Is there asymmetry with the eyelids?
•
Does one or both of the eyelids droop?
•
Is nystagmus (involuntary "wiggling" movement) evident?
•
Are the eyes teary or watery?
•
Are they reddened or appear irritated?
Results
If any of these questions are answered YES, refer the child to the
primary care physician with a suggested referral to an ophthalmologist
or optometrist.
...............................
Pupillary Response
Purpose: To determine the presence or absence of the pupillary reflex to a
light source.
Equipment: penlight
Procedures:
•
If the child wears glasses, they should be removed
•
In a room with dim lighting, position the child so that he or she is not
facing a window or other light source.
•
Direct a penlight 4" to 6" at the center of the child’s forehead.
•
Turn the penlight on for 2 to 3 seconds while observing the right eye for
pupil constriction.
•
Turn the penlight off and watch for pupil dilation. Wait one minute and
repeat the procedure for the left eye.
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COLORADO VISION SCREENING GUIDELINES
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Results
Pass:
Each eye shows rapid, smooth constriction of the pupil when stimulated by the
light, followed by smooth dilation in the absence of the light.
Fail:
Either pupil fails to react to the light source, or reaction (constriction) is
sluggish, jerky, or there appears to be a different reaction in either eye. Refer
to PCP with suggested referral to an ophthalmologist or optometrist.
Note: Certain medications affect the pupillary reflex and could account for an
abnormal pupil response to light. Regardless, abnormal pupillary reflex should
be referred whenever observed, since this may suggest a neurological
abnormality.
...............................
Cover/Uncover Test
Purpose: To detect a constant muscle imbalance or misalignment of the eyes
(a type of strabismus).
Description: Observing the person's eyes for movement while alternately
covering and uncovering the eyes. Binocular vision, or the ability of the eyes
to establish fusion and re-establish fusion, is being tested.
Equipment: A small, interesting target object and an occluder.
Procedures:
•
Align your eyes with the child's eyes. This is best done with the screener
sitting and the infant or younger child being held in the lap of an adult in a
upright position.
•
Hold the target object 12 to 13 inches away from the child's eyes directly
in front of him or her.
•
Permit the eyes to fixate on the target object by allowing 2 to 3 seconds
of observation of the object. (Fixation can be checked by moving the
target object back and forth and watching whether the child's eyes
follow.)
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
•
Cover the right eye with the occluder, watching the left eye for any
movement. Leave covered for 2 to 3 seconds. Watch for movement the
whole time. This is observation for tropia.
•
Remove the cover away from the bridge of the nose, watching the right
eye for any movement. Allow 2 to 3 seconds for both eyes to fixate on the
target object again. Watch for movement the whole time. This is
observation for phoria. (For young children, the target object may need
to be manipulated or changed to maintain attention.)
•
Cover the left eye with the occluder, watching the right eye for any
movement. Leave the eye covered for 2 to 3 seconds, and watch for
movement the whole time. This is observation for tropia.
•
Remove the cover away from the bridge of the nose, watching the left
eye for any movement. Allow 2 to 3 seconds for both eyes to fixate on the
target object again, watching during that time for movement. This is
observation for phoria.
•
Repeat the procedure several times to be assured of observations.
•
(See full description of the cover, uncover procedure in the appendix)
Results
Pass:
Neither eye moves.
Fail:
The observed uncovered eye moves, consistently, usually horizontally,
vertically or diagonally while the child has h/her gaze fixated on an object in
the distance. Refer to PCP with suggested referral to an ophthalmologist or
optometrist.
.....................................
Fixation
Purpose: To determine the presence of a sustained visual gaze.
Equipment: Use a colorful one inch object that is silent and a single piece of
cereal, such as a Fruit Loop.
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
Procedures:
•
Position yourself facing the child at the child's eye level.
•
Repeat procedures with one inch object and single Fruit Loop piece.
When presenting the cereal piece it should be placed on a piece of white
paper.
•
Present the largest object approximately 12 inches in front of the child's
nose at eye level and observe the child's eyes.
•
Both eyes should be directed toward the object for at least two seconds.
Use of initial noise to get attention is acceptable, but do not provide
continuous sound stimulation.
Results
Pass:
Child fixes on object with both eyes for at least two seconds.
Fail:
Child does not fixate on object, or fixates with one eye only. Refer to PCP with
a suggested referral to an ophthalmologist or optometrist.
...............................
Follow Skills
Purpose: To observe ocular-motor development.
Equipment: Small (two to three inches in size), brightly colored object.
Procedures:
•
Sit facing the child at the child's eye level.
•
Present the object approximately 12 inches in front of the child's nose at
eye level.
•
When the child has fixated on the object, move the object slowly to the
right along the horizontal plane 6" to 8"( (taking 2 to 3 seconds to cover
the distance), then slowly move the object back to the central starting
point.
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
•
Stabilize the chi!d's head if the child does not naturally follow with eyes
only. This can be accomplished by having the caregiver gently place
his/her hands on the child’s head.
•
Repeat the procedure, moving the object slowly to the left and back to
the starting point.
Results
Pass:
Smooth, continuous movement with the eyes remaining in symmetrical
alignment.
Fail:
Tracking with one eye only, or one or both eyes fail to maintain gaze at object.
Refer to PCP with a suggested referral to an ophthalmologist or optometrist.
Note: Infants younger than six months old may track with less that mature
levels of smooth, coordinated movement. Refer only those with markedly poor
performance on these procedures.
...............................
Corneal Reflection Test
The Corneal Reflection Test (Hirshberg Test) is used to determine a tendency
toward an ocular muscle imbalance. To perform this test, a penlight is held
three feet in front of the child’s eyes. The child is asked/encouraged to look at
the light. The examiner should note whether the light is symmetrically
reflected in each cornea. If the light is asymmetrical in either eye, the child
does not pass this test and a possible ocular muscle imbalance may be
present.
.....................................
Photo Refraction Test: Photo Screener
Note: There are several technologies available at this time for use in vision
screening very young children. Each camera is accompanied by an illustrated
manual that should be studied carefully. The following is only a brief
description of standard procedures.
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
Purpose: To detect refractive errors such as myopia (nearsightedness),
hyperopia (farsightedness) and astigmatism (distorted image).
This
photoscreening camera is a special purpose camera designed to accentuate
the” red eye" appearance in a child for screening and diagnostic purposes. All
photoscreeners are designed to provide an objective assessment of refractive
errors at any age. It is a screening device and does not substitute for a full
ophthalmological or optometric eye exam with refraction. The camera is not a
refractometer but it can give an indication of refractive errors.
Procedures: The camera's sensitivity is dependent upon the size of the
subject's pupils. Larger pupils allow greater sensitivity of the camera system.
To avoid the need to dilate pupils, the camera is designed to be used with
children and adults in an undilated state without the use of medication. In
order to maximize the pupil size, taking photographs in a very dim
environment is important. The room should be optimally dim, so as to just be
able to see the child's face. In rooms without variable illumination it is
recommended that all lights be turned off and a night light be placed in the
room to create sufficient dim illumination. The night light should be out of view
of the child so that it does not distract the child's attention from the camera.
The pupils should be allowed to dilate for 10 to 30 seconds. Use this time to
properly focus the photoscreener on the child.
Note: The attention span of young infants is very brief (a few seconds) and
therefore attracting their attention to the camera at the appropriate time is
crucial to taking accurate photographs. If the infant is not looking straight at
the camera, off-center fixation occurs which lowers the sensitivity of the
screening tool.
Results:
Most screening cameras require reading by a trained vision expert at a central
location.
REFER TO MANUAL
Fail:
When the child fails to pass the criteria described in the manual, the parents
should be given the screening results form to be taken to the family PCP with
a suggested referral to an ophthalmologist or optometrist.
QUESTIONS TO CONSIDER WHEN SCREENING THE VISION OF
CHILDREN WHO ARE DIFFICULT TO SCREEN
Erin, J.N. & Paul, B. (1996). Functional vision assessment and institution of
children and youths in academic programs. In A. L.. Corn & a. Koenig
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
(Eds.), Foundations of low vision: Clinical and functional perspectives
(p.229). New York, NY: American Foundation for the Blind Press.
When screening children who are difficult to screen, consider appropriately
phrasing the following questions so that the child’s caregiver is comfortable
supplying the information needed.
•
Communication: Does the child intentionally communicate about what he
or she sees? What behaviors give information about the child's vision?
•
Medical diagnosis: Does the child have a medical condition that may
affect vision? If so, how?
•
Medication: Does the child take medication regularly or occasionally?
How does the medication affect his or her vision?
•
Motivation: What materials does the child prefer for leisure activities?
How does the child express his or her preferences?
•
Physical state: Is the child more alert at some times than others? When
is he or she the most responsive and the least responsive? Does the
child demonstrate more visual control after physical activities?
•
Positioning: What is the child's preferred position? Does the child use
vision differently in various positions? Can he or she change body or
head positions to alter vision?
•
Sensory responses: Is the child hypersensitive or hyposensitive to
sensory stimuli? Does the child demonstrate unusual sensory responses
(such as intense startle, tactile defensiveness, or attraction to strong
visual effects)? What is his or her preferred learning mode?
•
Social interaction: Does the child react positively to unfamiliar people?
Does he or she visually or otherwise distinguish between familiar and
unfamiliar people? Is the child motivated by social interactions, or does
he or she find them aversive?
REFERRAL AND FOLLOW-UP PROCEDURES
•
If there are any concerns of the parent/caregiver/screener, refer the child
to PCP. Give parent a list of eye care specialists in the area.
•
If there are no observable problems, and there are no concerns of the
parent/caregiver/screener, and the child does not meet any of the high
risk criteria, the child passes the screening and is screened again in one
year.
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COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
•
If there are no observable problems, and there are no concerns of the
parent/caregiver/screener, but the child meets any of the high risk
criteria and is under the age of three years, the child passes the
screening and is screened again at the next recommended age.
Additionally, information is provided to the family and local service
provider about: high risk indicators of visual problems; how to observe
visual performance; and resources to contact, if vision problems are
observed at a later date.
•
If there are no observable problems, and there are no concerns of the
parent/caregiver/screener, but the child meets any of the high risk
criteria. and is three years or older, a referral is suggested to an eye care
specialist.
•
If the child has any observable eye condition such as excessive
tearing, redness, eye deviation, misalignment, drooping eye lid, or
cataract, refer the child to his or her PCP and suggest a referral to
an eye care specialist. Give parent a list of eye care specialists in
the area.
•
If the child has observable difficulty with one or more of the
behavioral items on the screening tool, refer the child to his or her
PCP and suggest a referral to an eye care specialist. Give parent a
list of eye care specialists in the area.
•
If the parent/caregiver/screener still has questions and the team is
unable to make a determination of whether or not the child is having
visual difficulty, refer the child to his or her PCP and suggest a
referral to an eye care specialist. Give parent a list of eye care
specialists in the area.
The screening team member assigned follow-up will contact the
parent/caregiver by telephone within two weeks of the screening to follow-up
on the families response to the screening. Each screener will have a copy of
the screening results that were given to parents. The results form will be the
basis for the follow-up phone call. Screeners will document whether or not
parents/caregivers followed the recommendations of the screening, and the
results of the visit if the child was seen by an eye care specialist.
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21
COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
Chapter 2:Forms
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22
COLORADO VISION SCREENING GUIDELINES
FOR INFANTS AND TODDLERS
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23
Colorado Department of Public Health and Environment
Health Care Program for Children With Special Needs (HCP)
Colorado Vision Screening for Infants and Toddlers
Child's Name: ___________________________ DOB: ________________________
Parent's Name: ________________________________________________________
Address: _____________________________________________________________
General History: High Risk Populations for Visual Problems
Cerebral Palsy
Prenatal Infection ______ Syndrome _______ Deaf/Hard of Hearing ______
Postnatal Infection______ Prematurity ______ Prenatal Exposure to Toxins ______
If the child is on medication, please list the names of the medication(s): _____________________________
Possible Signs of Visual Impairment in Infants/Toddlers
(parent history / examiner evaluation)
Does the family have concerns about the child’s vision? yes
no
If so, what are their concerns: __________________________________________________________
___________________________________________________________________________________
•
•
•
•
•
•
•
•
•
•
•
Child has history of watery/red/inflamed eyes or red/encrusted/watery/swollen lids.
Child's eyes are visibly out of alignment and do not focus together.
Child does not give eye contact.
Child holds toy up close to face or is inattentive unless toy has sound cue.
Child squints/frowns when looking at a person or an object.
Child hesitates to reach or move.
Child assumes postures such as head bent down or tilted for visual concentration.
Child does not follow a moving object with eyes.
Child misses objects in a certain location of his or her visual field.
Child does not appear to be visually aware of or interested in h/her surroundings.
Child does not react to light or seems excessively sensitive to light.
Is there a family history of vision problems:
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes ____
yes ____
no___
no___
no___
no___
no___
no___
no___
no___
no___
no___
no___
yes____ no____
If so, who and what types of vision problems: _________________________________________________
Visual Screening Procedures
Appearance of Eyes:
Are the child’s eyes aligned?
Yes
No
If not aligned, describe deviation: eye turned in_____(right/left) eye turned out____ (right/left)
Nystagmus____
Opacity______
Droopy eye lid(s)_______
Red/Irritated___
Teary_______
Mattered_____
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24
Pupillary Response:
Right Eye
O Brisk
O Absent/Sluggish
Left Eye O Brisk O Absent/Sluggish
Muscle Balance Tests:
Corneal Reflection Test:
O Symmetrical
O Asymmetrical
Cover/Uncover Test:
Right Eye
O No Movement
O Movement
Left Eye
O No Movement
O Movement
Face child, obtain fixation, occlude one eye, look for redress movement occurring in the eye left uncovered,
remove occluder, repeat with next eye.
Near Fixation Skills (eight to 18 inches from face) - Observe one eye at a time.
One inch object
O Steady (eyes lock gaze in unison)
O Fleeting
Froot Loop/cereal piece
O Steady (eyes lock gaze in unison)
O Fleeting
Follow Skills
Horizontal Follow Skills
O Eyes move together
Vertical Follow Skills
O Eyes move together
O Smooth
O Segmented
O Smooth
O Segmented
Results of Photo Refraction Screening
O Pass
O Fail
Referral Criteria
High Risk Population by age three, if no observable visual problems occur before that time.
Immediate referral, if there is poor performance on any of the above items and/or if the family continues to
be concerned about the child's general visual performance.
Name of Examiner
Date of Screening
References
Anthony, T., Story, A.., & Patterson, J. (1990). Vision screening form for children who are young or who
have special needs. Unpublished document.
Author (1996) Texas early childhood intervention vision screening form. Austin: Texas School for the
Visually Impaired
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25
HOW TO PREPARE FOR THE EYE
EXAMINATION APPOINTMENT
1.
As possible, schedule the appointment at a time of the day
that is good for your child.
2.
Be prepared to provide a family history of visual and health
problems.
3.
Be prepared to give a medical and developmental history
of your child.
4.
Be prepared to tell the eye doctor about your observations
of your child’s visual skills.
5.
Bring “entertainment” items for your child, as well as toys
that she/he visually prefers.
6.
Write your questions down in advance.
7.
Whenever possible, bring your spouse, a friend, or a
trained teacher to help listen to the doctor’s impressions.
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26
Health Care Program for Children with Special Needs (HCP)
Telephone: (303)692-2370; FAX: (303)782-5576
SCREENING PERMISSION
Annual vision screening for all Children from 6 to 36 months has been recommended by the
Colorado Department of Health and Environment. Early identification of vision loss and
appropriate treatment greatly reduce the chances of later problems.
I hereby consent to the provision of vision screening for:
(Full Name of Child)
(Parent or Legal Guardian)
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(Date of Birth)
(Date)
27
Health Care Program for Children with Special Needs (HCP)
Telephone: (303) 692-2370; FAX: (303) 782-5576
Child’s full name:
Date:
Parents name:
Telephone:
Screener:
Telephone:
Your child passed the screening because:
______
Your child demonstrated no observable visual problems.
______
Your child demonstrated no observable visual problems, but there are concerns that your child
may develop some visual difficulties. Information regarding high risk indicators of visual
problems; how to observe visual performance, and resources to contact, if vision problems are
observed at a later date has been given to you.
______
Your child should be rescreened. Date:
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28
Health Care Program for Children with Special Needs (HCP)
Telephone: (303) 692-2370; FAX: (303) 782-5576
This screening suggests that your child see his or her primary care physician for a possible
referral to an eye care specialist for further visual examination because:
you, the caregiver, or screener has concerns regarding this child's visual development
there are concerns that your child may develop visual problems. Information has been
given to you regarding high risk indicators of visual problems; how to observe visual
performance; and resources to contact if vision problems are observed at a later date.
your child has an observable eye condition(s) of: (list)
your child had observable difficulty with one or more of the behavioral items on the
screening tool, including: (list)
you, the caregiver, or screener has questions and the team was unable to make a
determination of whether or not the child is having visual difficulty
Thank you for participating in the Colorado Vision Screening Project. Together, we can help to
ensure that your child receives any needed eye care services. With your permission, you will be
receiving a telephone call within three months to assist you in any follow-up you may wish to
pursue.
Date of follow-up:
D:\106763445.DOC
Results:
29
Health Care Program for Children with Special Needs (HCP)
Telephone: (303)692-2370; FAX: (303)782-5576
Dear
(Child's name) has been screened through the Colorado vision screening pilot project. This child
is being referred to you because:
the parent, caregiver, or screener has concerns regarding this child's visual
development
the child meets high risk criteria
the child has an observable eye condition(s) of:
the child had observable difficulty with one or more of the behavioral items on the
screening tool, including
the parent, caregiver, or screener has questions and the team was unable to make a
determination of whether or not the child is having visual difficulty
Thank you for following up this child's visual progress. It is our goal to work with you in identifying
possible visual problems as early as possible, so that appropriate interventions can be made.
Please add this to the child's records.
Sincerely,
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30
Health Care Program for Children with Special Needs (HCP)
Telephone: (303)692-2370; FAX: (303)782-5576
RELEASE OF INFORMATION
It is generally agreed that sharing information regarding the results of screening with those
individuals and agencies that are concerned with the child's health and development is in the best
interest of the child. Commonly these individuals and agencies include the child's primary care
provider and local public health agency. Please initial the agencies that you wish to receive the
screening results.
I hereby agree to have the results of vision screening shared with the following individual or
agencies.
copy to parent/legal guardian (this copy may be shared with any person or agency at the
parent's or guardian's discretion)
copy to local public health agency
copy to primary care provider
copy to eye care specialist
(Full Name of Child)
(Parent or Legal Guardian)
D:\106763445.DOC
(Date of Birth)
(Date)
31
Health Care Program for Children with Special Needs (HCP)
Telephone: (303) 692-2370; FAX: (303) 782-5576
PARENT FEEDBACK TO THE COLORADO VISION SCREENING PROGRAM
Who referred your child for vision screening? (self, doctor)
Yes
•
•
•
•
•
•
•
•
•
•
•
No
I received a clear description of what was to take place
and what to expect
I felt that the people with whom I came in contact
honestly cared about me and my child and were
interested in my concerns.
I felt welcomed at the screening and was introduced to
people that I didn't know.
My time was respected by attempting to keep to the
schedule and by informing me of any delays.
I understood why each test was used with my child and
what it was supposed to tell about my child's vision.
I felt the staff explained test results clearly in a way that
was easy for me to understand.
I felt there was enough time throughout the evaluation
process to:
discuss results.
develop recommendations.
have my questions answered.
I felt that my input and opinions were valued as
recommendations were being developed.
I felt the recommendations were helpful.
It is clear to me what next steps should take place.
I know who to call if I have additional questions or need
help carrying out recommendations.
Additional comments that could improve this screening process:
Thank you for answering these questions. This form will be used by The Screening Program to continually improve screening services
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Health Care Program for Children with Special Needs (HCP)
Telephone: (303) 692-2370; FAX: (303) 782-5576
Dear Dr:
The Colorado Department of Public Health and Environment is piloting a universal vision screening project
for children ages 6 through 36 months of age. Your community has been selected as one of two sites in
Colorado. The goal of the project is to establish guidelines and procedures which will ultimately be
implemented throughout the state. The screening protocol which has been developed has been the result of
a national search for best practice information. Through this project, we are planning on collecting date to
validate the use of different screening practices.
We recognize the importance of early detection and treatment of eye disorders in young children. As such,
we are asking for your assistance in the follow-up process. A vital part of the screening process is what
happens to the child who does not pass the screening. Timely referral and appropriate follow-up eye care is
essential.
We value you expertise and look forward to your participation in this community project. We would
appreciate your taking a few moments to complete and return the enclosed questionnaire. This information
will help us to develop follow-up resources for infants and toddlers who need early eye care. Please direct
your questions to me at (303) 692-2413.
Sincerely,
Paula Hudson, Ph.D.
Health Care Program for Children with Special Needs (HCP)
PH/re
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Health Care Program for Children with Special Needs (HCP)
Telephone: (303) 692-2370; FAX: (303) 782-5576
COLORADO UNIVERSAL VISION SCREENING PROJECT
QUESTIONNAIRE OF EYE CARE SPECIALISTS
Thank you for completing this survey. Your information will provide us with valuable knowledge regarding
the available eye care services for infants and toddlers. Please return your completed survey to: Paula
Hudson, Colorado Department of Public Health and Environment, Health Care Program for Children
with Special Needs (HCP), 4300 Cherry Creek Drive South, FCHSD - HCP - A4, Denver, Colorado
80246-1530.
Please fill in the blanks and circle the appropriate responses.
Name:
Phone Number:
Address:
Are you willing to participate as a referral source and for follow-up consultation with project personnel?
YES
Are you an
Optometrist


NO
Ophthalmologist
Does your practice provide eye care to children ages six months to three years?
YES

NO



What does a standard exam include for children ages six to 36 months?
family history
behavior/medical history of child
ophthalmic exam
pupillary exam
ocular motility exam
extraocular muscle function exam
external examination
intraocular pressure
refraction after dilation
retinoscopy exam
ophthalmoscopy
general fix and follow
What is the typical cost of an eye exam for a young child?
Would you be interested in any of the following?
information regarding educational services for infants and toddlers with low vision.
information regarding the Colorado Universal Screening Project.
information regarding evaluating vision of children with multiple impairments
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CHAPTER 3 - COVER-UNCOVER TEST
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CHAPTER 4 - OBSERVATION OF VISION PROBLEMS
Parents and professionals who are with a child for several hours each day can
help to detect vision problems by carefully watching the child’s behavior. If a
child shows one or more of the following signs or symptoms, a referral should be
made to the appropriate personnel such as the family pediatrician, the school
nurse, and/or the local Child Find program.
The following signs and symptoms under APPEARANCE are reason for medical
attention. If the signs and symptoms under BEHAVIOR or COMPLAINTS
continue even though screening results were within normal limits, the child should
be referred for a professional eye examination.
APPEARANCE
1.
One or both eyes that turn inward or outward, or one eye is slightly higher
or lower than the other eye. (Tropia or Phoria)
2.
Crusty or red eyelids. (Blepharitis)
3.
Eyes that are in constant, rapid motion. (Nystagmus)
4.
Drooping eyelid(s) which may or may not interfere with vision. (Ptosis)
5.
Pupils of different sizes or different reactions to light and accommodation.
6.
Glands that are enlarged, inflamed or otherwise infarcted.
Chalazion)
(Stye,
BEHAVIOR
1.
Covers or closes one eye for critical seeing.
2.
Tilts head to one side for critical seeing.
3.
Thrusts head forward to see distant objects.
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4.
Loses place often while reading.
5.
Tries to “brush away” a blur.
6.
Rubs eyes often or blinks often while reading.
7.
Not interested in activities which require critical seeing.
8.
Frowns or squints when looking at or trying to see distant objects.
9.
Stumbles often over objects, is awkward.
10.
Holds book or work too close or too far away.
11.
Holds body tense when reading or looking at distant objects.
12.
Shows poor eye muscle coordination.
COMPLAINTS (ABOUT)
1.
Sensitivity to light.
2.
Burning or itching of eyes or eyelids.
3.
Seeing double or blurred vision.
4.
Words “run together” or “jump”.
5.
Headaches, usually after a critical visual task.
6.
Nausea or dizziness.
7.
Cannot “see” the blackboard.
If you notice one or more of the signs and symptoms in any child, please make a
referral to the appropriate resource personnel.
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COLORADO VISION SCREENING GUIDELINES
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CHAPTER 5 - NORMAL VISION DEVELOP
HOW DOES NORMAL VISION DEVELOP?
In order for a person to see, several things must happen: 1) the eyes must be
able to catch light and send signals to the optic nerves; 2) the optic nerves must
be able to send signals to the brain's visual cortex. For a person to see normally,
all parts of this visual system must work.
The visual system is not fully developed at birth. An infant with normal vision will
not be able to see things as clearly as an adult with normal vision. The baby's
eyes do not work together all the time until about four months of age. Pathways
carrying signals to the brain, and the brain itself, continue to develop during the
early years of life.
As the eye and the visual cortex of the brain develop, a child's ability to see
details improves. As the eyes begin to work together, the brain learns to combine
the images from the two eyes into a single image. The child learns how to use the
signals in the brain to recognize things, such as faces and toys, and to tell the
difference between things that look similar. Vision continues to develop until a
child is about nine years of age.
Young children spend much of their first three years of life learning how to see.
The many different vision skills developed during this time will serve the children
throughout their lives. Infants are aware of lights and people before paying
attention to them, or understanding what they are seeing. Infants then react to
lights before reacting visually to faces or toys. Once an infant fixates on lights,
people or objects, he or she will begin to follow or track them. Infants respond to
lights, people and objects that are close prior to those that are far away. Infants
respond to lights, people or objects found in the outer portions of the visual field
before responding to those within the central field of vision.
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SEQUENCE OF DEVELOPMENT OF VISION
Infants visually respond to people and objects that are familiar prior to those that
are new. Infants look at parts of faces and objects before seeing the whole face
or object at once. Infants respond to simple patterns prior to those that are more
complex. Infants respond to large patterns and objects prior to the smaller ones.
The following descriptions describe how vision develops in young children:
•
The first four months: The newborn sees a blurred world of light and dark
patterns. Within the first four months, however, he or she should begin to
follow moving objects with the eyes and to reach for things, first by chance
and later more accurately, as eye-hand coordination and depth perception
begin to develop.
•
Four to six months: Infants should now begin to turn from side to side and
use his or her arms and legs. Eye movement control and eye/body
coordination skills should develop further.
•
Six to eight months: Both eyes should focus equally.
•
Eight to twelve months: Infants should now be mobile, crawling and pulling
themselves up. They should begin to use both eyes together to judge
distances. They can grasp and throw objects with greater precision.
•
One to two years: Eye-hand coordination and depth perception should
become well developed and abstract terms should be understood.
•
Two to three years: Toddlers should become more interested in exploring
their environments and in looking and listening.
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Developmental Sequence of Functional Visual Abilities: Birth to Three
Years
Adapted by Sandra Handy, Deaf-Blind Consultant, Utah School for the Deaf and
Blind Darla, Saunders, R.N., Part H coordinator, Baby watch Early Intervention
Basic Eye Responses
Awareness responses:
•
Respond to a light source (0-1 month)
•
Respond to faces (0-1 month)
•
Respond to objects (0-2 months)
•
Respond to movement (1-2 months)
Attending Responses
•
Look at lights, object or people at close
•
Visually attend to the actions/movement of people (1-3 months)
•
Watch movement of own hands and feet (4-8 months)
Fixation and Gaze Shift
•
Hold momentary fixation on an object (0-1 month)
•
Make sustained eye contact (2-4 months)
•
Shift gaze from one object to another object at 6-12 inches (2-4
months)
•
Shift gaze from a near object held at 6-12 inches to a far object held
at I to 3 feet, and from a far object to a near object (3-5 months)
Tracking (e.g. smooth dual eye movement when following an object)
•
Track slowly, horizontally from peripheral to midline moving lights,
objects, and faces (1 month)
•
Track vertically to midline (2 months)
•
Track horizontally across midline (4 months)
•
Track movement of people who are 10-15 feet across a room (4-6
months)
•
Visually follow a falling object (4 months)
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Basic Visual Motor Responses
Visually Directed Gross Motor Movements
•
Locate an object and move toward it (4-8 months)
•
Avoid object/people when moving toward a target (7-12 months)
•
Locate a path visually and move through it (7-12 months)
•
Imitate motor-play activities such as peek-a-boo (7-12 months)
•
Visually locate objects pointed to by another person (9-12 months)
•
Point to objects within reach (12-18 months)
•
Point to objects in the environment (12-18 months)
Visually Directed Fine Motor Movements
•
Reach for and grasp objects (5-7 months)
•
Place an object in an open container (12-18 months)
•
Fit objects together using visual cues (12-24 months)
•
Random scribble, all directions (18-24 months)
•
Match familiar objects using visual cues (18 months- 3 years)
•
Imitate placement of objects after visual observation (2-3 years)
•
Nest or tower objects (2-3 years)
•
Complete form boards, simple puzzles, or peg board designs (2-3
years)
Basic Visual Discrimination Responses
Awareness of Familiar Objects and People
•
Attend to familiar people (1-3 months) Attend to familiar objects (34
months)
Discrimination of Differences in Shape, Form, Color, etc.
•
Locate self and others in a mirror or photograph (18-24 months)
•
Name simple color pictures of familiar objects (2-3 years)
•
Point to/indicate single item in a picture (2-3 years)
Discrimination of Parts and Positions
•
Reposition familiar object if given upside down (1-2 years)
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•
•
•
•
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Indicate awareness of missing part of significant change in familiar (23 years)
Locate a specific object from several similar objects (2 years)
Identify missing parts of objects (3 years)object (18 months - 3 years)
Identify common objects which are partially hidden in the environment
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Normal Visual Development
by Irene Toper, M.Ed.
Vision is one of your baby’s most important ways to
learn about the world. The first three years of life is
a critical time for your baby to be visually alert and
learning about objects, people, and events.
Your baby sees some things from the moment of
birth, because much of the visual system has
already developed. Vision develops in a predictable
way; here’s what happens before and after birth.
The ages are averages; every baby is a little
different.
Before Birth
· 16 weeks fetal age: Eye movements occur.
·
25 weeks fetal age: The light-sensitive cells in
the eye can be seen.
·
28 weeks fetal age: The muscles that control the
pupils have developed.
·
32 weeks fetal age: The cornea-covering the
lens-appears. The optic nerves-the visual
pathways that connect the eyes and the brainare in place.
Your baby is able to visually learn about the world,
but the visual systems are not fully developed. Here
are some of the changes that should occur in your
baby’s visual behavior during the first three years.
·
The way the pupil reacts to light continues to
develop.
·
Begins to recognize your face. At first, baby
scans the angles, shapes, and outline of the
face. By 3 months, scans the eyes and mouth,
unless there is an unusual feature - such as
glasses, glitter, or paint-added to the face.
4 months
· Sees detail and color. Probably knows your
face from a stranger’s and prefers yours.
·
Can accommodate - shift focus from one
distance to another - from eight to thirty inches
away and converge-turn the eyes inward-with
good precision to look at a target at close range.
·
Binocular vision-the ability to focus both eyes on
one object and see one image-is fairly well
developed and is closely linked to
accommodation and convergence. Should
respond to horizontal and vertical lines, and
black-and-white checkerboard and bull’s eye
patterns.
6 months
· Watches everything that is nearby.
·
At a slightly earlier age, baby gazed at hands,
batted and swiped at hanging objects, and tried
to grasp objects. Now baby stretches both arms
out to grasp an interesting-looking object or to
touch your face. This shows that some depth
perception-the ability to see the threedimensional relationship between objects-is
developing.
·
Reaching skills continue to develop until 12
months. Baby watches the activities of others,
looks at pictures in books, and dumps and fills
containers.
At birth
· The cornea becomes fully transparent.
·
Can tell colors apart, but the ability is not mature
for all colors until 2 to 3 months.
·
Until about 3 months, sees things to the side
better than to the front.
Your baby’s ability to notice details and differences
quickly increases, but attention to different nearby
areas may be limited. The ability to shift attention
rapidly increases during the first 2 months.
3 months
The shape of the cornea makes close objects a little
out of focus. Sees best at a distance of eight to ten
inches.
12 to 18 months
· Practices visual-motor skills: Scribbles, builds a
tower with cubes, attempts in imitate strokes,
places a circle in a one-piece puzzle and pegs
into a pegboard.
© 1990 by Communication Skill Builders, Inc.
This page may be reproduced for clinic or home use.
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WHAT VISION PROBLEMS COULD BE DETECTED BY SCREENING?
If there is a problem with the child's eyes, vision will not develop normally. It is
possible that vision may get worse without intervention. For this reason, it is
important to find and treat children with problems affecting the visual system as
early as possible. Young children with vision problems are much less likely to
explore the world around them. They may miss many important experiences. This
causes them to have trouble learning to sit, to stand, to walk, to learn the names
for objects, as well as other difficulties. The earlier a vision problem is treated, the
more likely a child is to develop normal skills.
Amblyopia
Amblyopia ("lazy eye") is poor vision in one eye (or poorer vision in one eye than
the other) that occurs when the brain “turns off" the poorer eye because it cannot
use the eyes equally at the same time. There are three major causes of
amblyopia:
1.
2.
3.
strabismus;
a focusing problem causing one eye to be more blurry than the other, and;
an eye disease such as a cataract preventing one eye from seeing clearly.
Strabismus
Strabismus is the most common cause of amblyopia. In strabismus, one eye is
usually directed straight ahead and the other may be turned inward, outward,
upward, or downward. The eyes may appear to be crossed, drifting, or
wandering. Normally, both eyes are aimed at the same target and the brain puts
the two "pictures" together in one 3-D picture (depth perception). If one eye is
aimed at a target that is different from the other eye, two different pictures are
sent to the brain. Because the brain cannot fuse these different pictures, it
"ignores" or suppresses the picture from the eye that is turned. This can cause
decreased vision (amblyopia) in one eye and loss of depth perception. The earlier
in life the eyes are straightened, the better chance the child has of developing
good vision and depth perception.
Other vision problems that can be detected by screening are focusing
problems, such as nearsightedness, farsightedness, and astigmatism, that
can be corrected with glasses. Medical conditions that can affect visual
development, such as cataracts or disorders of the inner eye, may also be
picked up by screening.
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CHAPTER 6 - TYPES OF VISION PROBLEMS A CHILD CAN HAVE
Vision problems can appear at any time during a child's development. They can
be caused by inherited conditions that affect other members of the family.
Problems that affect vision can occur while the mother is pregnant or after the
baby is born.
There are several types of vision problems. Some affect how sharply or clearly a
child can see. Others affect the child's ability to use the eyes together. Different
types of visual problems are described in this section.
Poor visual acuity
People who have poor visual acuity do not see as clearly as they should. There
are two types of visual acuity - distance and near. When a person has poor
distance visual acuity, things that are far away seem blurry. When a person has
poor near visual acuity, things that are close seem blurry. There are different
conditions, such as cataracts, refractive errors, and strabismus, that can cause a
child to have poor visual acuity. The treatment for poor visual acuity depends on
what causes it. However, most children who are nearsighted or farsighted can be
treated with corrective lenses.
Amblyopia is the name for poor visual acuity in one eye or worse visual acuity
in one eye than the other that cannot be improved immediately with glasses
alone. Some treatments for amblyopia include glasses, patching and eye drops.
It is very important to find amblyopia as early as possible. The longer the poorer
eye is not used, the harder it will be to develop good vision and the brain's ability
to use the eyes together.
Loss of visual field
A person who has a loss of visual field does not see equally well in all directions
when the head and eyes are held still. A person with a loss of visual field may see
well in front, but not well to the sides; this person is said to have tunnel vision.
Another person with a loss of visual field may see well to the sides, below, or
above, but not in the center; this person is said to have good peripheral vision,
but poor central vision. Another may have islands of vision surrounded by "blind
spots". Loss of visual field can be caused be a problem with the eyes, the nerve,
or the brain. A child with loss of visual field may need to have special help in
learning how to use the part of the visual field that is intact.
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Poor stereopsis (depth perception)
A person who has poor depth perception has difficulty judging which things are
closer and which are farther away. To have good depth perception, a person
must be able to use both eyes together. Poor depth perception may indicate
problems with the eye or the brain. It is very important to find poor depth
perception as early as possible. The longer it exists, the harder it will be for the
brain to develop the ability to use the eyes together.
Poor color vision
A person who has poor color vision might have trouble matching colors or
telling certain colors apart. It is very rare for a person to be unable to see colors
at all. Poor color vision runs in families, and most people who have it are born
with it. It can also be caused by diseases that affect the eye or by certain
prescription drugs. It usually cannot be corrected.
Poor visual processing
A person who has poor visual processing or cortical visual impairment has
difficulty understanding what the signals form the eyes mean. Often, the eyes and
the optic nerve are healthy, but the brain cannot make sense of the signals. Poor
visual processing can be caused by severe head injuries, infections that affect
the brain, or a lack of oxygen at birth. In some cases, cortical visual impairment
can change over time.
WHAT CONDITIONS INTERFERE WITH NORMAL VISUAL DEVELOPMENT?
There are many conditions that interfere with normal visual development. The
most common ones are described in this section.
Genetic syndromes
Some vision problems are part of a group of conditions (syndrome). Some
syndromes, such as Marfan's or Usher's, run in the family. Other syndromes,
such as Down Syndrome, are caused by a genetic problem that occurs at the
time of conception.
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Prenatal illness in mother
Some illnesses that a mother may have while she is pregnant can cause vision
problems. Some examples are toxoplasmosis, rubella, cytomegalovirus, genital
herpes, and syphilis.
Perinatal conditions
Problems that occur around the time a baby is born can cause difficulties with
vision. Some examples are prematurity (being born several weeks before the due
date), low birth weight, problems that cause a baby not to get enough oxygen at
birth, or being on a ventilator. Babies who weigh less than 3 pounds, 5 ounces at
birth have four to five times the rate of vision problems than infants who weigh
more.
Refractive errors
When light enters the eye, it is bent so that it focuses on a place at the back of
the eye called the retina. When light focuses correctly, it causes a clear image to
be formed on the retina. A refractive error occurs when the light does not focus
on the retina and an clear image is not formed. There are three types of refractive
error: myopia or nearsightedness (poor distance visual acuity), hyperopia or
farsightedness (poor near visual acuity) and astigmatism (distorted vision). A
large difference between the refractive errors of the two eyes is called
anisometropia. Refractive errors can usually be corrected with glasses or contact
lenses.
Most children are normally farsighted and do not need glasses as adults do,
because their focusing muscles are very strong. They can compensate for this
unless they are extremely farsighted, in which case they might need glasses.
Muscle imbalance
Each eyeball has six muscles connected to it. These eye muscles hold the
eyeballs in place, and make the eyes move up, down, and to the side. When the
muscles work correctly, the eyes move together. Strabismus, a form of muscle
imbalance, occurs when a person's extraocular muscles do not work together.
When the eyes are not turned in the same direction, a child sees two images.
The brain cannot make sense of both images at the same time, so it ignores the
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image from one eye. If the image is ignored for too long, the visual acuity in that
eye will decrease and depth perception will be impaired.
Types of muscle imbalances are esotropia (one eye turns in), exotropia (one
eye turns out), hypertropia (one eye turns up), and hypotropia (one eye turns
down). Sometimes the muscle imbalance is not obvious because the brain works
to keep the eyes together. The child is then said to have a tendency to turn the
eyes in (esophoria), out (exophoria), up (hyperphoria), or down (hypophoria).
At times, the child might not be able to keep the eyes working together and goes
between a phoria and a tropia. This condition is called and intermittent tropia.
Muscle imbalances run in families, and most of the time are not associated with
any other physical problem. In some cases, muscle imbalances occur when a
nerve to the muscle is damaged, when the part of the brain that controls eye
movement is damaged, or when one eye has poorer visual acuity than the other.
Treatment for strabismus depends on what causes it. Most muscle imbalances
can be treated with glasses, eye drops, surgery, and in some cases eye
exercises.
Nystagmus
Nystagmus is a name for a condition that causes the eyes to move in a rhythmic
jerky manner. The eyes of most people with nystagmus move from side to side.
Other people have eyes that move up and down, in a circle, diagonally, or in a
combination of directions. It can be associated with other disorders, so children
with nystagmus should be seen by an eye care provider as early as possible.
A child with nystagmus does not see objects moving, but does have blurred
vision. The child may be able to quiet the eye movements by holding the head
and eye in a certain direction, thus getting better visual acuity.
Cataracts
Cloudiness in a part of the eye called the lens is called a cataract. This
cloudiness scatters light as it enters the eye or keeps light from entering the eye.
It is important for a young child with cataracts to be treated early, so that the
visual system can develop normally. Cataracts can be caused by illness that the
mother has during pregnancy and from certain drugs used during pregnancy. It
can be a part of a syndrome, such as Down or Marfan's. Cataracts can be treated
by surgery. Afterwards, a child must wear a contact lens or glasses (if cataracts
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were removed from both eyes to focus properly. Older children may be treated by
a surgical procedure that involves implanting a lens within the eye. (intraocular
lens implant).
Retinal detachment
The retina is a thin layer of tissue that lines the inside of the eye. Retinal
detachment occurs when part of the retina is separated from the back of the eye
and loses its source of nourishment. Blindness develops in the area of the visual
field that relates to the part of the retina that is separated.
Retinal detachment can be caused by several conditions. Some examples are
severe head injury, as seen in child abuse or shaken baby syndrome, or direct
trauma to the eye. Usually surgery is needed and., if successful, some of the
vision is restored.
Retinopathy of prematurity (ROP)
ROP is a condition which can cause retinal damage, including detachment, in
babies who are born several weeks before their due date. It appears to occur
most often in infants with low birth weight who have received oxygen over a long
period of time. When the retina is not fully developed, it is more likely to form
abnormal blood vessels and tissue that can lead to retinal detachment. Laser
surgery can be used in some cases to treat the retina and prevent retinal
detachment; sometimes the retina detaches anyway, and more extensive surgery
is required. It is important to follow a child who has been treated for retinopathy of
prematurity, because the child remains at high risk for developing problems with
visual acuity, muscle imbalances, and retinal problems in the future.
Retinoblastoma
Retinoblastoma is the name of a malignant eye tumor that can cause death if it
is not treated. Most retinoblatomas occur in children under three years of age. It
is usually found when a doctor examines the eyes and notices a difference in the
reflex coming from the back of each eye. It may not be noticed until it causes the
eye to look cloudy or until the child develops a muscle imbalance. If the tumor is
found very early, it is possible to shrink it with radiation. Sometimes, some vision
can be saved. Often, the eye must be removed. An artificial eye can be placed in
the eye socket to give the child a more natural appearance. Retinoblastoma can
be hereditary
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CHAPTER 7 - GLOSSARY OF TERMS ASSOCIATED WITH VISION
accommodation
adjustment of the lens by means of the ciliary body
in order to focus an image on the retina
acuity
"sharpness of vision' that is measured and
recorded using an internationally recognized twofigured indicator, such as 20/20
ambliopia
"dimness of vision" or reduced visual acuity in one
eye not usually correctable by a lens
anisometropia
a condition in which the two eyes have different
refractive errors requiring a different lens correction
for each eye
antibiotic
Medication used to suppress infection due to
microorganisms
astigmatism
a defect in the curvature of the cornea or lens of
the eye; causes a ray of light to not sharply focus
on the retina but spread irregularly
binocular vision
the ability to use both eyes at the same time to
focus on the same object and to combine the two
images into a single image - giving good depth
perception
Legal blindness
in the United States: central visual acuity of 20/200
or less in the better eye after correction; or visual
acuity of better than 20/200 if there is a field defect
in which the widest diameter of the visual field
subtends an angle distance no greater than 20
degrees (some states include up to 30 degrees)
cataract
partial or complete loss of the transparency of the
crystalline lens or its capsule
congenital
present at birth
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conjunctiva
the mucous membrane covering the anterior
portion of the globe of the eye, reflected upon the
lids and extending to their free edges
conjunctivitis
an inflammation of the conjunctiva
contact or corneal lens
lenses constructed so that they fit directly on the
eyeball; used for the correction of vision and for
cosmetic reasons
convergence
the process of directing the visual axes of the two
eyes to a near point, with the result that the pupils
of the two eyes are turned towards the nose
Convergence, near point
the nearest point at which the two eyes can direct
their gaze simultaneously; normally about three
inches from the nose
corneal graft
operation to restore vision by replacing a section of
diseased cornea with transparent cornea
cover test
a two-part test in which the first part (unilateral)
determines the presence or absence of strabismus
and the second part (alternate) determines the
direction and magnitude of either a strabismus or
heterophoria
cycloplegics
a group of drugs instilled into the eye, which cause
temporary paralysis and relaxation of the ciliary
muscles which control accommodation and dilation
of the pupil; often used to ascertain the error of
refraction
dacrocystitis
inflammation of the lacrimal sac (tear sac)
depth perception
the ability to distinguish the relative distance of
objects in visual space diopter unit of measurement
of strength or refractive power of lenses or prisms
(a lens having one diopter of refraction power will
bring parallel rays of light to focus at a distance of
one meter)
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COLORADO VISION SCREENING GUIDELINES
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divergence
turning the direction of the gaze of the two eyes
outward
emmetropia
normal refractive condition of the eye, where a
distance object is focused sharply on the retina
without any accommodation effort
epicanthus
a fold of skin extending over the inner corner or the
eye; in some infants can give the appearance of
strabismus; tends to recede as the bridge of the
nose narrows in the course of early childhood
esophoria
a tendency for one eye to turn inward; not
generally recognizable unless tested for
esotropia
one eye is turned inward (cross-eyed)
exophoria
a tendency for one eye to turn outward
exotropia
one eye is turned outward (wall-eyed)
field of vision
the entire area which can be seen at one time
without shifting the head or eyes
fixate
to focus one's gaze on an object
floaters
particles in the internal eye fluids that are
sometimes visible to the person through his/her
eyes
follow-up
to maintain contact with a person who requires
services beyond screening in order to learn
whether services were obtained and whether
diagnostic information is being used
footcandle
a unit of measure for light intensity (the amount of
light shed by a standard candle at the distance of
one foot)
fundus
the inner surface of the back part of the eye
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COLORADO VISION SCREENING GUIDELINES
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fusion
combining the images from the two eyes into one
perceived visual image
glaucoma
disease of the eye marked by a mechanical
increase in the intraocular pressure causing
organic changes in the optic nerve and defects in
the visual field
heterophoria
a tendency of the eyes to deviate normal position
for binocular fixation, counter-balanced by
simultaneous fixation and fusion (prompted by the
desire for single binocular vision) - deviation is not
usually apparent, in which cases it is called latent
heterophoria
heterotropia
when one or more muscles are out of balance, one
eye may turn in while the other fixes - it may be a
divergent or vertical muscle (squint, strabismus,
cross-eye)
Hirschberg's Test
a gross test for the presence of or approximate
magnitude of strabismus - done by simultaneously
comparing the position of reflected light of a single
source from the corneas of the two eyes
hordeolum
inflammation of one or more of the sweat glands
found around the roots of the eyelashes (sty)
hydropthalmus
a rare congenital defect in which the eyeball is
abnormally large as a result of pressure elevationpresent at birth or develops early in infancy
(congenital glaucoma)
hyperopia
a refractive error in which the eyeball is too shortcorrection requires a convex (plus) lens; the eye
has a natural ability to compensate for low
amounts of hyperopia; people vary greatly in their
ability to make adjustment without discomfort or
loss of visual performance and this ability declines
with age (farsightedness)
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COLORADO VISION SCREENING GUIDELINES
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hyperphoria
a tendency for one eye to deviate upward
hypertropia
one eye is turned upward
intraoccular
inside the eye
iritis
inflammation of the iris; condition marked by pain,
inflammation and discomfort from light
isolated" test method
using a window cover card over the eye chart so
that the person being tested sees only one letter or
symbol at a time
keratitis
inflammation of the cornea
lacrimal gland
gland located just above the outer corner of each
eye, which secretes tears
light perception
the ability to distinguish light from dark, a minimum
standard of visual acuity
"linear" test method
using a window card cover over the eye chart so
that the person being tested sees one line of letters
or symbols at a time
monocular
pertaining to the use of one eye
myopia
nearsightedness; a person can see near objects
clearly while distant objects appear blurred
nystagmus
a rapid involuntary movement back and forth of the
eyeballs
occluder
any device used to block the vision in one eye;
often a stiff piece of paper or paddle-like instrument
oculus dexter (O.D.)
right eye
oculus sinister (0.S.)
left eye
oculus uterque (O.U.)
both eyes
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COLORADO VISION SCREENING GUIDELINES
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ophthalmologist
a licensed physician who specializes in diagnosis
and treatment of defects and diseases of the eye,
performing surgery when necessary or prescribing
other types of treatment, including medication,
glasses, contact lenses, and optical aids
ophthalmoscope
an instrument for viewing the retina and other
intraoccular structures
optician
a person who measures lenses, fits them into
frames, and adjusts the frames to the wearer
optometrist
a licensed doctor specializing in vision, an O.D.
who examines the eye and vision system,
diagnoses vision disorders or imperfections, and
prescribes or provides treatment-including glasses,
prisms, contact lenses, vision treatment, and/or
medications
orthoptics
the technique dealing with the diagnosis of muscle
and sensory imbalances and the therapy
necessary to restore sensory and motor
coordination of the eye
orthoptist
a person who uses a series of scientifically planned
exercises for developing or attempting to restore
the normal teamwork of the eyes
patching
covering one eye temporarily to promote usage of
the other eye; often a treatment of amblyopia
peripheral vision
ability to perceive presence, motion, or color of
objects outside the direct line of vision
phoria
a latent tendency toward crossed eyes - condition
not usually observed
photophobia
an abnormal vision intolerance to light; painful
sensitiveness to light
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presbyopia
decreased elasticity of the lens in the eyeball
Causing some loss of accommodation making it
difficult to focus on near objects, and usually seen
in older persons
prism
a wedge shaped piece of glass or plastic which
possesses the power of refracting (bending) rays of
light toward its base
pterygium
a condition in which a triangular membrane forms
extending from the conjunctiva onto the cornea
ptosis
a drooping of the upper lid due to weakness or
paralysis of a portion (or branch) of the third nerve
which controls the levator muscle that raises the lid
refraction
the bending or deviation or rays of light in passing
obliquely from one medium to another of different
density; the determination of the refractive errors
(qv) of the eye and their correction by prescription
glasses
refractive error
a defect in the eye that prevents light rays from
being brought to a single focus exactly on the
retina - nearsightedness (myopia) farsightedness
(hyperopia) and astigmatism are all refractive
states
retinal detachment
separation of the retina from the underlying
vascular or choroid layer of the eye breaking
connections between the rods and cones and the
pigment layer most often the result of a hole or tear
in the retina
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COLORADO VISION SCREENING GUIDELINES
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Snellen Eye Charts
standardization of the size for each target on the
different lines of a chart was developed by a man
named Snellen. Most conventional and widely
used eye charts conform to Snellen standards,
although the term “Snellen” is commonly used to
refer to the alphabet chart. Charts that conform to
“Snellen” standards include: alphabet charts,
illiterate or tumbling “E” charts, H: O: T: V charts,
picture charts and number charts
strabismus
the two eyes are not directed at the same point
(squint)
suppression
when the image of an object from one eye is not
perceived
tracking
•
keeping a record of the services a child
receives after referral and of the child's
development related to those services
•
uniform movement of the eyes as they follow an
object or a light source; when carefully
observed, the ability to track uniformly and
fluidly is evidence of good muscular function of
the eyes
tropia
one eye turns out of line from the other eye that is
focusing; often recognized during observation
visual acuity
the sharpness or clearness of a person's vision
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COLORADO VISION SCREENING GUIDELINES
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CERTIFICATE OF TRAINING
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