Learners with Blindness or Low
Vision
EDU381
Immaculata University
Katherine Speicher
6/14/10
Definition and Classification:
• The two most common ways of describing
someone with visual impairment are the legal
and educational definitions. Laypeople and
medical professionals use the former; the
latter is the one educators favor. The two
major classifications are blindness and low
vision.
Legal Definition
• The legal definition involves assessment of visual activity and field of
vision. A person who is legally blind has visual acuity of 10/200 or less in
the better eye even with correction (e.g. eyeglasses) or has a field of vision
so narrow that its widest diameter subtends an angular distance no
greater than 20 degrees. The fraction 20/200 means that the person sees
at 20 feet what a person with normal vision sees at 200 feet. (Normal
visual acuity is thus 20/20.) The inclusion of a narrowed field of vision in
the legal definition means that a person may have 20/20 vision in the
central field but severely restricted peripheral vision. Legal blindness
qualifies a person for certain legal benefits, such as tax advantages and
money for special materials.
• In addition to this classification of blindness, there is a category referred to
as low vision (sometimes referred to as partially sighted.) According to the
legal classification system, persons who have low vision have visual acuity
falling between 20/70 and 20/200 in the better eye with correction.
Educational Definition
• Many professionals, particularly educators, find the legal classification
scheme inadequate. They have observed that visual acuity is not a very
accurate predictor or how people will function or use whatever remaining
sight they have. Although a small percentage of individuals who are legally
blind have absolutely no vision, the majority can see to some degree.
• Many who recognize the limitations of the legal definitions of blindness
and low vision favor the educational definition, which stresses the method
of reading instruction. For educational purposes, individuals who are blind
are so severely impaired they must learn to read Braille, a system of raised
dots by which people who are blind read with their fingertips. It consists
of quadrangular cells containing from one to six dots whose arrangement
denotes different letters and symbols. Alternatively, they use aural
methods (audiotapes and records.) Those who have low vision can read
print, even if they need adaptations such as magnifying devices or largeprint books.
Psychological and Behavioral
Characteristics
• Language Development
Most authorities believe that lack of vision does
not have a very significant effect on the ability to
understand and use language. Because auditory more
than visual perception is the sensory modality through
which we learn language, it’s not surprising that
studies have found that people who are blind are not
impaired in language functioning. The child who is
blind is still able to hear language and might even be
more motivated than the sighted child to use language
because it’s the main channel through which he or she
communicates with others.
Intellectual Ability
Performance on Standardized Intelligence Tests
• At one time, it was popular for researchers to
compare the intelligence of sighted people
with that of persons with blindness. Most
authorities now believe that such comparisons
are virtually impossible because finding
comparable test is so difficult. From what is
known, there is no reason to believe that
blindness results in lower intelligence.
Conceptual Abilities
• It is very difficult to assess the performance of children with visual
impairment on laboratory-type tasks of conceptual ability. Many
researchers, using conceptual tasks originally developed by noted
psychologist Jean Piaget, have concluded that infants and very
young children who are blind lag behind their sighted peers. This is
usually attributed to the fact that they rely more on touch to arrive
at conceptualizations of many objects, and touch is less efficient
than sight.
• However, these early delays don’t last for long, especially once the
children begin to use language to gather information about their
environment. Touch, however, remains a very critical sense
throughout life for those who are blind. As one person who is blind
described it, he “sees with his fingers.”
Orientation and Mobility (O&M)
These skills refer to the ability to have a sense of where one is in
relation to other people, objects, and landmarks (orientation) and to move
through the environment (mobility). O&M skills depend to a great extent
on spatial ability.
• Cognitive Mapping – A non sequential way of conceptualizing the spatial
environment that allows a person who is visually impaired to know where
several points in the environment are simultaneously. This allows for
better mobility than does a strictly sequential conceptualization of the
environment.
• Obstacle Sense - A skill possessed by some people who are blind, whereby
they can detect the presence of obstacles in their environments. Research
has shown that it is not an indication of an extra sense, as popularly
thought, but is the result of learning to detect subtly changes in pitches of
high-frequency echoes.
• Doppler Effect – The phenomenon of the pitch of a sound rising as the
listener moves toward its source.
Academic Achievement
• Phonological Awareness – Learning to read
Braille is similar in some important ways to
learning to read print. Phonological awareness
is an important component of learning to read
print or Braille.
Social Adjustment
• Subtle Visual Cues – Those who are sighted
take for granted how often we use visual cues
to help us interact socially. Children with
visual impairments often need to be taught
directly how to use these cues. Facial
expressions, such as smiling, are a good
example of visual cues that don’t come
spontaneously for persons who are visually
impaired.
Stereotypic Behaviors
• Any of a variety of repetitive behaviors (e.g.
eye rubbing) that are sometimes found in
individuals who are blind, autistic, severely
intellectually disabled, or psychotic. They are
sometimes referred to as stereotypies or
blindisms.
Physical Symptoms/Characteristics
• Signs of Possible Eye Trouble in Children
If one or more of these signs appear, take your child to an eye doctor right away
What do your child’s eyes look like?
• Eyes don’t line up, one eye appears crossed or looks out
• Eyelids are red-rimmed, crusted or swollen
• Eyes are watery or red
• How does your child act?
• Rubs eyes a lot
• Closes or covers one eye
• Tilts head or thrusts head forward
• Has trouble reading or doing other close-up work, or holds objects close to eyes to see
• Blinks more than usual or seems cranky when doing close-up work
• Things are blurry or hard to see
• Squints eyes or frowns
What does your child say?
• “My eyes are itchy,” “my eyes are burning” or “my eyes feel scratchy.”
• “I can’t see very well.”
• After doing close-up work, your child says, “I feel dizzy,” “I have a headache” or “I feel
sick/nauseous.”
• “Everything looks blurry” or “I see double.”
Diagnosis & Identification
• Snellen chart – Used in determining visual acuity. The
chart consists of rows of letters or Es arranged in different
positions, and the person’s task is to indicate in what
direction the “legs” of the E’s face. Each row corresponds to
the distance at which a normally sighted person can
discriminate the letters. It does not predict how accurately
a child will be able to read print.
Diagnosis & Identification
• Functional Vision Assessment – Used by the vision
teacher to determine how students use their vision in
everyday situations. The teacher observes the student in
his or her daily activities, taking note of how the student
functions under a variety of conditions and on a variety of
tasks.
Potential Causes of Visual
Impairment
• Causes Affecting Children and Adults
When considering both children and adults, the most
common visual problems are the result of errors of
refraction. Refraction refers to the bending of the light rays
as they pass through the various structures (cornea,
aqueous humor, pupil, lens, vitreous humor) of the eye.
Myopia (nearsightedness), hyperopia (farsightedness), and
astigmatism (blurred vision) are examples of refraction
errors that affect central visual acuity. Although each can
be serious enough to cause significant impairment (myopia
and hyperopia are the most common impairments of low
vision), wearing glasses or contact lenses usually can bring
vision within normal limits.
• Causes Primarily Affecting Children
• For children, cortical visual impairment (CVI) is now the leading cause
of visual impairment in the Western world. While most causes of visual
impairment are due to abnormalities in the eye itself, CVI results from
widespread damage to parts of the brain responsible for vision.
• Several other visual impairments primarily affect children and are
often due to prenatal causes, many of which are hereditary, such as
congenital (meaning present at birth) cataracts and glaucoma may also
be responsible. Another congenital condition is retinitis pigmentosa.
This is a hereditary disease resulting in degeneration of the retina. It
can start in infancy, early childhood, or teenage years. It usually causes
the field of vision to narrow (tunnel vision) and also affects one’s
ability to see in low light (night blindness.) Included in the “prenatal”
category are infectious diseases that affect the unborn child, such as
syphilis and rubella.
• Retinopathy of Prematurity (ROP) results in abnormal growth of blood
vessels in the eye, and began to appear in the 1940’s in premature
infants. In the 1950’s, researchers determined that excessive
concentrations of oxygen often administered to premature infants
were causing blindness.
• Strabismus is a condition in which the eyes are directed inward
(crossed eyes) or outward
• Nystagmus is a condition in which there are rapid involuntary
movements of the eyes, usually causing dizziness or nausea, and
sometimes indicates a brain malfunction and/or inner-ear problems.
Instructional Strategies/SDI
• Accommodations: These are changes in the way in which the child is treated
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in order to best accommodate the child’s physical, cognitive, or emotional
challenges.
The instructor should allow extra time when needed, for tactual exploration,
when appropriate, slower visual/Braille reading, etc.
Co-teaching– The general and special education teacher should make time to
collaborate and plan for student needs that may arise at any time.
Encourage the use of aids/devices.
Provide extra storage space for special equipment/materials.
The instructor should read out loud what is being written on the board.
Include the visually impaired student in as many class activities as possible.
Scheduling accommodations - Extended time on tests for aid to read questions to
child or for the child to use Braille.
Special seating – If the student has low vision, seat he/she in the front of the
classroom.
Alternative assessments (required by IDEA)
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Modifications: These change the academic or curricular demands made of a child
to better fit the child’s ability. The student with little or no sight will possibly require
special modifications in four major areas:
Braille
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Literary Braille
Nemeth Code
Unified English Braille
Portable Braille Notebooks
Perkins Brailler
Slate and Stylus
Braille Bills
• Use of Remaining Sight
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Large print books
Magnifying Devices
• Listening Skills
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The importance of listening skills for children who are blind or of low vision cannot be
overemphasized. Teachers should provide a classroom environment as free from
auditory distractions as possible.
Listening skills are becoming more important than ever due to the increasing
accessibility of recorded material. Listeners can play the material at normal speed, or
can use a compressed-speech device that allows them to listen to about 50-275 words
per minute. This method works by discarding very small segments of the speech.
• Orientation and Mobility Training
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The Long Cane - a mobility aid used by individuals with visual impairment, who sweep it
in a wide arc in front of them proper use requires considerable training. The long cane is
the mobility aid of choice for most travelers who are blind.
Human Guides - Human guides allow those with visual impairment to have the greatest
freedom in moving about safely. However, most O&M specialists do not recommend
that this be the primary means of navigation because it fosters too much dependence
on other people.
Guide Dog - Dogs trained for the purpose of helping people who are blind navigate the
environment. Guide dogs are generally not recommended for children, as they require
extensive training for the user.
Tactile Maps - Embossed representations of the environment. Touching raised symbols
representing streets, sidewalks, buildings, and other objects allows blind people to
orient themselves to their surroundings.
Link to Sample SDI
• http://docs.google.com/viewer?a=v&q=cache:O4BZOKtrrU4J:w
ww.cde.state.co.us/cdesped/download/pdf/blvLVRelatedGoalsObjectives.pdf+SDI+blind+visually+impaired+goal
s&hl=en&gl=us&pid=bl&srcid=ADGEESjJognd_SvFkGbvpJ2pWQJ
99PCe-Hcx0XyEOnhYVH2xjzKPqG7jI63-oYA5ds7mBrfvfBS29LmKhRZcG1K224aZvoMncxtTPPSMf428o2bfeBmswqzhH24ppMvSEk2e4IEZjZ&sig=AHIEtbTucuolit_GpxL0Hj4J7D0vcK8NaA
Sample Goal Assessments
Academic goals for visually impaired students will often be the same
as the goals set for the rest of the students, but many times the methods
of assessment must be altered.
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Teachers can monitor progress in Braille skills involved in reading and mathematics
using CBM (curriculum based management.)
The Neale Analysis of Reading Ability-Braille Version – an assessment of reading skills
that has been standardized for children with blindness or low-vision.
Monitoring Functional Skills and Quality of Life - O & M instructors can monitor travel
skills using GPS devices.
Academic outcomes may be assessed using Braille versions of standardized academic
tests.
Parental Strategies
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Early intervention – Researchers have documented that immediately after birth infants
begin processing a wealth of visual information in their environment. This fact makes it
easy to understand why intensive intervention should begin as early as possible to help
the infant with visual impairment begin to explore the environment.
Encourage and aid in O&M training.
Encourage the use of aids/devices.
Do not treat any person with visual impairments as helpless.
Give praise or rewards when achievements are made.
Aid in the teaching of and encourage independent living skills.
Aid in the transition to adulthood and independence for adolescents with visual
impairments.
• Video Segment
Western Pennsylvania School for Blind Children
http://www.youtube.com/watch#!v=60PBjXXjmOo&feature=related
• Useful Links
www.preventblindness.org/children/trouble_signs.html
www.mdsupport.org/snellen.html
www.i-see,org/eyecharts.html
www.preventblindness.org
www.preventblindness.org/eye_tests/near_vision_test.html
http://www.blindkids.org/
http://www.wonderbaby.org/index-topics/resources.html
http://www.spedex.com/napvi/