Certified Paraoptometric
Assistant Review Course
CPOA
Provision
 The Self Study Course for Paraoptometric Assistants and
Technicians, Self Assessment Examination, and the AOA PS
CPOA Review Course are not prerequisites for taking the
paraoptometric certification examination given by the
Commission on Paraoptometric Certification (CPC). Using
these study materials and/or taking the CPOA Review course
does not guarantee passing the paraoptometric certification
examination given by the CPC. Attending the CPOA Review
Course is not a substitute for studying for the paraoptometric
certification examination given by the CPC. This course is
designed to review previously acquired knowledge.
This review course is not intended to be a
substitute for responsible study and
preparation for the CPOA test.
Outline
 Office Operations (13%)
 Ophthalmic Optics and Dispensing (20%)
 Testing and Procedures (20%)
 Special Procedures (17%)
 Refractive Status of the Eye and Binocularity (13%)
 Basic Ocular Anatomy and Physiology (17%)
Office Operations
(13%)
Office Procedures
Office Procedures Manual
“Official rulebook of the practice”
 Used to clarify the policies of the practice
Records Management
Filing Systems
Alphabetical
Simplest and most widely used
Numerical
Decreased chance of misfiling
Cross index card required
Recall Systems
Types of Patient Recall
Pre-appoint (most effective)
Postcard or letter
Computerized
Recall list generated
Email
Record Corrections
Recording errors can happen - What to do?
Draw a single line through the error
Initial
Example: Monday, June 29, 3008 sjm 2008
Never, never erase to
completely remove
Confidentiality
What is HIPAA?
Health Information Portability &
Accountability Act
Minimum Necessary Principle
Requires office to take reasonable steps to
limit the use or disclosure of, and request
for, PHI to the minimum necessary to
accomplish intended purpose
HIPAA Regulations
Confidentiality
Safeguards
Release of records
Legal record of ownership
Release of records
Computer use
Patient Handling
Telephone Techniques
Greeting
Taking messages
Handling requests for information
Handling complaints
Making appointments
Confirming appointments
Patient Flow
Control the appointment schedule
Have thorough knowledge of
different types of appointments
and time required by each doctor
for specific appointments
Public Relations
Types of correspondence and brochures
“Welcome to the practice”
Referral letters
Consultation letters
School reports
Legal reports
Patient information pamphlet
Patient Handling
Triage Categories
 Emergency
- immediate
 Urgent - 12-24 hours
 Routine - next available appointment
 Ask
questions to determine
Bookkeeping Procedures
Accounts Receivable
Accounts Payable
Petty cash
Banking Procedures
Deposits
Reconciling bank
statements
Office Finances
Presentation of fees
Do not apologize
Collection of fees
Cash, check or credit card?
Professional Issues
Role and function of the eye care professional
Delegation
Certification vs. licensure
Liability and Malpractice
Paraoptometrics are:
Responsible to provide the
highest level of service
possible
Protected under the employing
doctor of optometry’s
malpractice insurance
Conduct, Confidentiality & Ethics
To keep the patient’s visual welfare uppermost at all
times
To strive to see that no person shall lack for visual
care
To conduct ourselves as exemplary citizens
To promote and maintain cordial and unselfish
relationships with members of our profession
Excerpts from “Code of Ethics” adopted by the House of Delegates of the AOA June 28, 1944,
Modified in 2005
Hygiene & Infection Control
Asepsis
Hand washing
Instrument disinfection
Contact lens disinfection
Cross-contamination
Sterilization
Ophthalmic Optics
& Dispensing
(20%)
Prescriptions
Components
Sphere, cylinder, axis
Add power
Prism
Prism base direction
Ordering should include:
Jones Optical
5209 South Penn
Oklahoma City, OK 73109
638-7889
Whether on
order form or
online ordering
Patient
SPH
Jane Doe
CYL
DEC
In
+1.00 - 0.25
90
+1.00 - 1.00
Seg
Ht.
95
Width
2/23/01
Date
AXIS
OD
PRISM
PLASTIC
GLASS
Out
1/2 Δ
BU
SV
FDA Tested
1/2 Δ
Pup
BD
Dist
RND
EXEC
ST 28
LENT
TRIFOCAL
OS
A
D +2.00 20
D
+2.00 20
Set
F.P.D.
F
R
A
M
E
S
Size
58
ACCT:
28
Insert
Total
R
R
Dist
L
L
66
Lens Shape
A
B
BDG
16
ED
LOC UNCUT
Near
62
OTHER
Edge
Rimless
Grove
Drill
Metal
ZYL
Temp
Style
145
Safilo
Titanium 109
REMARK
SUPPLY
Color
Gray
OT30
TRAY#
Colour
PINK
1
2
3
GREEN
1
2
3
GRAY
1
2
3
BROWN
1
2
3
OTHER:
1
2
3
GRADIENT TO
 Lite
RX LENS
MISC
TAX
TOTAL
DATE
INVOICE
$
 Clear
Optical Cross
Optical cross is a diagram that denotes the
dioptric power in the two principal meridians
of a lens.
Hint: Think of the value of the numbers as they
are read off of the lensometer wheel.
Lens Clock Readings Example
+8.00
-5.00
Image from Sharp- Trawick
+8.00
Front Lens Surface
-3.00
Back Lens Surface
Optical Cross
Optical Cross Results
Plus cylinder notation:
+ 3.00
+3.00 +2.00 x 090
+ 5.00
Minus cylinder notation:
+5.00 -2.00 x 180
Hint: The sphere is “married” to the axis; the cylinder is the distance
between the numbers on the cross
Prescriptions: Transposition
Transposition
Combine the sphere and cylinder power
mathematically
Change the sign of the cylinder
Change the axis by 90 degrees
Hint: When combining positive and negative numbers, think in terms
of money. Example: -2.00 combined with +0.50 If you are $2.00
“in the hole” and you deposit $0.50, what is your balance?
Answer: $1.50 “in the hole”, or -1.50.
Prescriptions: Transposition
Transposition Examples
-1.00 +2.00 X 160
+1.00 -2.00 x 070
+1.25 -0.75 x 030
+0.50 +0.75 x 120
Plano +1.00 x 090
+1.00 -1.00 x 180
Prescriptions: Decentration
Decentration calculations
 Eye size plus distance between lenses
minus patient’s PD divided by 2.
Example:
Eye size = 58 +16 = 74
Patient’s PD = 62
74 – 62 = 12
12 divided by 2 = 6
Prescriptions: Vertex Power
Vertex Distance- distance between the
ophthalmic lens and the front of the patient’s
eye
Effective Power- change in the prescription
when the distance varies from the normally
refracted 13.5mm distance to where the
patient wears the RX.
Concerned with high Rx’s (-/+ 4.00)
Prescriptions: Vertex Power
Vertex distance and effective power
Lenses gain minus or lose plus power as
they are moved closer to the eye.
Conversely lenses gain plus or lose minus
as they are moved away from the eye.
Instruments used for verification
Lensometer
 Lens power and
axis location
 Presence, amount
and direction of
prism
Caliper
 Lens thickness
Instruments used for verification
Colmascope or Polariscope
 Progressive add markings
Geneva Lens Clock
 Base curve
Prescriptions: Prentice’s Formula
Prentice’s Prism Formula – if the patient is not
looking through the optical center of the lens
that has power, they are looking through
prism
Optical Center
Induced Prism
What Does Prism Do?
Displaces light
Light bends toward base
Image displaced toward apex
Verification of Prism
Determine optical center of lens
Compare with patient’s pupillary distance for
horizontal prism (base in or base out)
Compare with patient’s line of sight (LOS) for
vertical prism (base up or base down)
To Determine Base Direction
Prescriptions: Prentice’s Formula
Prentice’s Prism Formula
Prism = power x decentration (in cm)
Prism = lens power (in diopters) multiplied by
d in cm (Where d = amount the patient PD
varies from the major reference point in cm)
EX: -4.00(power) x .5cm (decentration in cm)
= 2 prism diopters
Optics: Light Rays
Rays move from left to right
 Converging Rays
 Diverging Rays
Prescriptions: Focal Length
Calculations
Formula: f (in meters) = 1/D
Focal length in meters (f) =
1 / D (reciprocal of power in
diopters)
Example: The focal length of 2.00 D lens:
f = 1 / 2.00 D f = .5 meter
Major Reference Point
The optical center of each lens
Also referred to as “prism reference point”
Point of intersection of the sphere indicators
and cylinder indicators during lensometry
Prescription: Prism
Prescribed when the two eyes do not align
properly
Can be induced when the optical centers of
the lenses do not line up with the patient’s PD
Prentice’s Rule- used to calculate induced
prism
Lenses: Convex & Concave
Plus lenses – prisms
stacked base to base
Minus lenses – prisms
stacked apex to apex
Lens Forms
Convex
Concave
Spherical Lens
A lens with the same
curvature across the surface
Toric/Cylindrical Lens
A lens that differs in curvature across the
surface
Flat Meridian
Steep Meridian
Base Curve
The measure of the general shape of the
lens
Used to determine lens power
Prescription Forms
Plus cylinder
Cylinder is ground on front of lens
-2.00 + 1.25 x 090
Minus cylinder
Cylinder is ground on back of lens
Most typically used form
-0.75 – 1.25 x 180
Basic Ophthalmic Lens
Types and Styles
Single vision
Spherical lenses
Planocylindrical lenses
Spherocylindrical lenses
 Aspheric lenses
Multi-focal lenses
Bifocal lenses
Trifocal lenses
Progressive addition lenses
Powers of the lens
Bifocal
The amount of power needed to be
added to the distance correction
Example: -2.00 -0.75 x 090 +1.00
add
Bifocal power = -1.00 -0.75 x 090
Courtesy of MattisonShupnick & Meister
Powers of the lens
Trifocal
Generally the top segment is
½ the power of the lower
segment
Progressive Addition Lens
Multiple powers increasing
upon downward gaze
Images courtesy of Mattison-Shupnick & Meister
Multifocal Placement
Bifocal Seg Height
Trifocal Seg Height
Lens Materials: Glass
Crown glass
Flint glass
Hi-Index glass
n: 1.52
n: 1.65
n: 1.9
Advantages: More scratch resistant, clearer
optics
Disadvantages: Heavier, less impact resistant
Lens Materials: Plastic
CR-39
Hi-Index plastic
n: 1.49
n: 1.54-1.60
Advantages: Lighter weight, more impact
resistant compared to glass, easily tinted
Disadvantages: More prone to scratches, less
ultra-violet (UV) protection on untreated lens
Lens Materials: Polycarbonate
Polycarbonate
n: 1.54-1.60
Advantages: Lighter weight, more impact
resistant compared to plastic, naturally filters
UV light.
Disadvantages: More prone to scratches,
chromatic aberration
Lens Materials: Trivex™
Trivex ™
n: 1.53
Advantages: Lightest material available; less
distortion; as impact resistant as polycarbonite,
highly resistant to cracking around holes when
used in drill mount frames; quality optics; natural
UV protection.
Disadvantages: Cannot be tinted darker than #2
Lenses: Index of Refraction
Definition: A comparison, or ratio, of the speed
of light in air to the speed of light in another
medium
Values
Speed of light in air: 186,000 mps
Air= 1.00
Water= 1.33
Lenses: Index of Refraction
Index of refraction (n)=
Speed of light in air/speed of light in
material
Hardening Methods
For impact resistance
Heat tempering
Lens placed in a vacuum and brought
close to melting point, then cooled rapidly
Chemical tempering
Lens placed in hot chemical bath for 15 –
17 hours
ANSI Standards
American National Standards Institute
Regulates the standard of tolerances for
ophthalmic lenses
Copy of ANSI Standards kept by lensometer
Z80.1
Impact resistance standard
Impact resistance of lenses subject to
individual test shall be measured with a 15.9
mm (5/8 inch) diameter steel ball weighing
not less than 16g (0.56 oz) dropped from a
height of not less than 127cm
(50 inches) or an equivalent impact
Z87.1
Basic Impact Standard
Impact resistance of lenses subject to
individual test shall be measured with a 1
inch diameter steel ball dropped from a
height of not less than 127 cm (50 inches)
or an equivalent impact
High-Impact Standard
Impact resistance of lenses subject to
individual test shall be measured with a ¼
inch BB fired at a rate of 150 feet/second
FDA Standards
Food and Drug Administration
Regulates the pharmaceuticals that are used.
Approves methods for disinfection
Special Prescription Considerations
High Minus/ Myodisc
Aphakia / Lenticular
Aspheric
Fresnel Prisms
Industrial / Occupational
Tints and Coatings
Colors
 Tint #1 – 65-80 light transmission
 Tint #2 – 45-60 light transmission
 Tint #3 – 15-40 light transmission
Mirror
Edge Coating
Sun and Glare Protections
Polarized Lens
Photochromatic
Ophthalmic Lens Coatings
Scratch resistant
Anti-reflective
Ultra-violet
Frames
Styles
Full frame
Semi rimless
Rimless
Frame Materials
Materials
Zyl
Metal
Stainless Steel
Memory Metals
Anatomy of the Frame
Frame front
Eyewire
Bridge
Hinge
Nosepads
Temples
Guard Arm
Eyewire
Frames Verification
Do Not Assume… Verify
Eyewire size
Bridge
Temple length
Standard Frame Alignment
Evaluate frame front
Evaluate for X-ing of the bridge
Evaluate eyewire for X-ing
Make sure frame front is even
Temple alignment follows front alignment
Evaluate endpieces
Evaluate hinges
Evaluate temples for 90-degree angles
Do temples close evenly
Eyewear Dispensing
4 Point touch
Tools Used For Frame Adjustments
Frame warmer
Adjusting Pliers
Nose pad adjusting pliers
Needle nose
Half round/ Flat jawed
Angling
Dispensing -Frame Alignment
Front- Xing
Coplanar
Face form - positive and negative
Frame Tilts
Pantoscopic
Retroscopic
Nosepad Adjustments
As viewed from front of frame
Vertical Angle
Bottoms of pads angled toward frame
front
Frontal Angle
Tops of pads angled inward
approximately 15 degrees
Nosepad Adjustments
Splay Angle
Edge of pads angled inward
approximately 15 degrees
Patient Instructions
Frames
Place and remove eyewear with two hands
Temples should be folded and stored in
frame case
Frame should be cleaned daily with mild soap
and water
Patient Instructions
Lenses
Cleaned as often as
necessary with recommended solutions
Frame Repair
Eyewire screw replacements
Nylon chord replacements
Realignments
Common Frame Adjustment
Problems - Vertex Distance
Increase vertex - bend both end pieces in
Decrease vertex - bend both end pieces out
Increasing vertex distance effectively raises
multifocal height and vise versa
Changing Height or Vertex
Distance
Moving pad arms up will raise height of frame
Moving pad arms down will lower height of
frame
Lengthening pad arms will increase vertex
distance
Shortening pad arms will decrease vertex
distance
Adjustment Problem
Unequal Vertex Distance
Unequal temple spread
Decrease temple spread on side that is
closer (In - In)
Increase temple spread on side that is
farther from face (out - out)
Unequal temple tension and bends behind ears
Adjustment Problems
Crooked Frames
One eyewire higher: bend the temple up on that
side to lower
One eyewire lower: bend the temple down on
that side to raise
Testing and Procedures
(20%)
Case History
Chief complaint
Reason for visit – recorded in patient’s
own words
History of present illness
Detailed information on chief complaint
Social history (age-appropriate)
Alcohol? Smoke? Occupation? Live
alone?
Ocular Symptions
Ask open-ended questions
Itching
Burning
Tearing
Redness
Irritation
Blurred vision
Other symptoms
Ocular History
Inquire on specific ocular problems or
conditions
Surgery
Injury
Vision training
Eye medications
Refractive history
Ocular History
Inquire on specific ocular problems and
conditions, such as:
Glaucoma
Cataracts
Keratoconus
General Health History
Rule out specific health problems
Current health status
Diabetes
High blood pressure
Heart disease
Other
Family Ocular History
Review Family History of
Cataracts
Glaucoma
Macular Degeneration
Other
Who has been diagnosed with
?
Medications
Name
Pharmaceutical and Over-the counter
Quantity
Frequency
Prescribed for
Does the patient take the medication as
directed?
Allergies
Medications
True allergies vs. side effects
Environmental
How does patient gain relief?
Refractive History
Past history of corrective lenses
Current corrective wear
Age of correction
State of correction
Quality of vision
Visual Acuity: Snellen Fraction
Numerator
Represents the testing distance in feet or
meters 20/_____; 6/______
Denominator
Represents the distance at which the letter
subtends a 5-minute angle of arc in
distance or meters. Also referred to as the
letter size.
Visual Acuity: Techniques for Testing
Monocular and binocular
With and without Rx
Distance and near
Pinhole acuity
Testing errors
Types of Acuity Charts
Snellen
Metric (Bailey-Lovie)
Low vision vharts
Illiterate vharts
Landolt “C” or rings
Tumbling “E”
Lighthouse charts
Pinhole Acuity
To determine if reduction
in vision is due
to refractive error
Vision Acuities
Testing Distances
Distance testing
20 feet or 6 meters is customary
Or Mirror method to assimilate equal
distance
Recording Results
The smallest line patient can read
If patient is able to read all of one line and one
two of next, then
20/25 +2 or 20/25+
If patient is consistently misses one letter, then
20/20-1 or 20/20-
Interpupillary Distance
Measurement
Distance and near
1
PD measuring ruler
2
3
4
5
6
7
1st measurement 60 mm
Pupillometer
1
2
3
4
5
6
7
2nd measurement 64 mm
Monocular PD measurement
Near Point of Convergence
Measure of the ability of both eyes to work
together
Blur/break/recovery
Measured in centimeters from the bridge of
the nose to the point of blur/break
Near Point of Accommodation
Ability of the eyes to focus at near
Binocular measurement
Amplitude of accommodation
Binocular or monocular measurement
Distance measured in cm
Extra-Ocular Muscle Testing
Pursuits
Movement of the eyes while following a
moving target
Saccades
Jumping movements from one target to
another
Cover Test
Assess heterophoria and heterotropia
Two separate tests - unilateral and
alternate
Tests are performed at distance and near
Unilateral test is performed first
Unilateral Cover Test
Determines heterophoria or heterotropia
Heterophoria = tendency
Heterotropia = constant
Determines frequency (constant or
intermittent)
Unilateral or alternating
Alternating Cover Test
Determines the direction
and magnitude of the
tropia or phoria
Eso - in
Exo - out
Exo
Hyper - up
Hypo - down
Hyper
Eso
Hypo
Eye Dominancy
Eye preference
Eye used for monocular viewing or sighting
Testing methods
Reasons for recording
Monovision contact lenses
Fusion / Suppression
Fusion
Blending of 2 images, one from each eye
Suppression
Subconscious inhibition of an eye’s retinal
image
Associated with strabismus
Worth 4 Dot
Maddox Rod
Dissociating test
One eye sees a red line, the other a white light
Pupillary Responses
Assure that the sensory pathway is working
Direct and consensual responses to light
Response to accommodation
Pupillary Response Recording
Example #1
P= pupils are
E= equal
R= round
R= react to
L= light and
A= accommodation
-/+RAPD (relative
afferent pupillary defect
Example #2:
5mm/4mm
2+ (reaction time)
R & R (round & reactive)
-/+ RAPD (also called
Marcus Gunn pupil)
Confrontation Fields
Screening for gross visual field defects
Comparison of examiner’s visual field
(known) to the patient’s (unknown)
Color Vision
Types of color vision tests
Pseudoisochromatic plates (PIP)
Farnsworth D-15
Farnsworth 100 hue
Nagel Anomaloscope
Color Vision: Method for Testing
Monocular vs. binocular
Test distance 75 cm (30 inches)
Illumination
 Macbeth daylight lamp
 Illuminant C lamp
Pseudoisochromatic Plates
Ishihara
14, 24, or 38
plates
Plate #1 can be
read by anyone, even
those with color
defects
Pseudoisochromatic Plates
Hardy-Rand Ritter (HRR)
Screening test to separate those
with defective color vision from those
with normal color vision
Classifies the type of defect
Indicates the extent of the defect
(mild, medium, strong)
Courtesy of Richmond Products
Farnsworth Dichotomous (D15)
Used to separate medium
and strong color
defect vs. normal
Courtesy of Richmond Products
Farnsworth Dichotomous (D15)
Patient color disk selection is shown in color, test results are plotted and diagnosis is recommended.
Courtesy of Richmond Products
Farnsworth 100 Hue Test
93 Colored Discs
Tray
Scoring Template
Calculates a
numerical score
Courtesy of Richmond Products
Anomaloscope
The software provides
capability for data
analysis and display.
Courtesy of Richmond Products
Color Vision Classifications
Trichromatism
Normal color vision
Protanope
Red deficiency
Deuteranope
Green deficiency
Tritanope
Blue-yellow deficiency
Normal
Dichromat
(red insensitive)
Stereopsis
Highest degree of depth perception
Purpose of test
Types of stereo tests
Titmus stereo fly
Randot
Reindeer
Butterfly
Stereo Testing: Method for Testing
Illumination (well-lit room light)
Testing distance 40 cm (16 inches)
Patient wears habitual Rx for near
Recording - in seconds of arc
Cat = 400 seconds of arc
Rabbit = 200 seconds of arc
Monkey = 100 seconds of arc
Exam Equipment
Retinoscope
Phoropter
Keratometer
Exam Equipment
Monocular Direct
Ophthalmoscope
Binocular Indirect
Ophthalmoscope
Biomicroscope
Exam Equipment
Optical Coherence Tomographer
Special Procedures
(17%)
Hard Contact Lens
Materials
1940s, 50s, 60s
Polymethylmethacrylate (PMMA)
1970s
Rigid Gas-permeable (RGP)
Silicone Acrylate
Fluoro-Silicone Acrylate
Parameters
Gas Permeable Lenses
Overall Diameter
Optical Zone Diameter
Back Vertex Power
Base Curve Radius
Peripheral Curves
Edge and Center Thickness
Parameters
Overall Diameter (OAD)
Secondary Curve
Width (SCW)
Optical
Zone
(OZ)
Secondary Curve (SC)
Peripheral
Curve Width
(PCW)
Peripheral Curve
(PC)
Contact Lenses
Materials
1970s
Soft Hydrogel (water-absorbing)
Silicon Hydrogels
Comparison of Soft and GP Lens
Advantages
Soft Lens
Good initial comfort
Variable wearing time
Occasional wear
Ability to enhance or change eye color
Stability in sports
Comparison of Soft and GP Lens
Advantages
Gas Permeable
 Clear, sharp vision
 Long-term comfort
 Stability/durability
 Ease of care
 Good ocular health
 Corrects small and large amounts of
astigmatism
Care and Handling
Hygiene
Hands
Case
Evaluate lens
Tears
Inverted
Lint
Solutions
Soft contact lens
solution for soft
contact lenses
Hard contact lens
solution for RGP’s
Soft Contact Lens Insertion
Place lens on finger tip
Verify lens is not inside out
 Taco Test
Manipulate lids for aperture
Place lens on eye
Release lower lid, then upper lid
Soft Contact Lens Removal
Pull lower lid down
Pinch lens off the white part of eye
Remove
Reverse hand positions for second eye
Hard & GP Contact Lens Insertion
Place the lens on the tip of middle finger of the
dominant hand
Looking down, pull up the top lid with the other
hand, pressing it against the bony margin of the
top brow
Looking ahead, pull down the lower lid with the
first or third finger of the “lens” hand.
Place the lens on the center of the eye
Hard & GP Contact Lens Removal
Bend head over table and look straight
ahead, opening eyes as wide as possible
Place the fingertips of your index finger at the
outer corner of the eye
Pull the lids laterally toward the ear, blink,
and catch the lens in the other hand held
close to the eye
Contact Lens Wearing Modalities
Daily wear
Flexible wear
Extended wear
Contact Lenses
Wearing Schedules
Soft lenses
4-6 hours plus 2 each day to
full time wear
Gas Permeable lenses
4 hours plus 1-2 each day to
full time wear
What is “Normal” Adaptation?
Appearance
Comfort
Vision
Lens Care Regimens
Soft lens care systems
clean
rinse
disinfect & store
protein removal
Gas permeable care
systems
clean
rinse
disinfect & store
protein removal
Blurred Vision – Soft Lenses
Residual astigmatism
Switched lenses
Inverted lens
Coated lens
Dry lens
Poor fit
Wrong prescription
Blurred Vision – Gas Permeable
Non-wetting lens surface
Switched lenses
Warped lens
Poor optical quality
Coated lens
Poor fit
Wrong prescription
Poor Lens Comfort
Soft Lenses
Tear
Poor edge
Dryness
Poor fit
Dirty lens
Gas Permeable
Poor wetting
surface
Poor blend
Bad edge
Redness
Adverse reaction to solutions
Uncomfortable edge
Wrong solutions used on lenses
Foreign body
Excessive movement
Improper application
Contact Lenses
Verification
Lensometer measures the vertex
power
Contact Lenses
Verification
Radiuscope measures the base
curve
Contact Lenses
Verification
Hand Magnifier - measures the
overall diameter (OAD), optic zone
(OZ), peripheral curve widths
(PCW, SCW)
Contact Lenses
Verification
V-Gauge or Slot Gauge - measures
the overall diameter (OAD)
Contact Lenses
Verification
Shadowgraphmagnifies and
projects the
contact lens
Special Lens Designs and Uses
Ballast
Toric
Truncation
Tints
Bifocal
Ordering Procedures
CONTACT LENS ORDER FORM
Patient Name:
John Doe
Specifications Ordered
Date
2/23/01
O.D.
B.C.R
7.89
S.C.R./W
8.90 /.3
I.C.R./W
P.C.R./W
110.9 /.3
O.Z.D.
8.0
Dia
9.2
Power
- 2.50
C.T.
.16
Blend
Med
Tint
Blue
Dot O.D.

Additional Information
 Accepted
 Rejected
Reason for return/reorder
Specifications Verified
Date
O.S.
7.81
8.80 /.3
10.8 /.3
8.0
9.2
- 2.50
.16
Med
Blue
O.D.
B.C.R
S.C.R./W
I.C.R./W
P.C.R./W
O.Z.D.
Dia
Power
C.T.
Blend
Tint
Verified by
 Returned for Credit
Date Returned
O.S.
Tonometry
Tonometry is the measurement of intraocular
pressure (IOP)
Tonometer Types
Indentation - Schiotz
Applanation - Goldmann; Tonopen
Non Contact
Schiotz (Indentation)
Goldman Applanation
Tonopen
Perkin’s Hand-held Applanation
Tonometer
Non-contact Tonometer
Classification of Visual Field Defects
Nerve Fiber Layer
Optic Chiasm
Optic Tract to Visual
Cortex
Arcuate Scotoma
Heteronymous
Bitemporal
Hemianopsia
Homonymous
Hemianopsia
Paracentral Scotoma
Congruent
Nasal Step
Incongruent
Monocular Visual Field Boundaries
60 Degrees superiorly
75 Degrees inferiorly
105 Degrees temporally
60 Degrees nasally
Physiological Blind Spot
15 Degrees temporal to fixation
Absolute scotoma
Types Of Visual Field Testing
Confrontation
Types Of Visual Field Testing
Tangent Screen
Types Of Visual Field Testing
Autoplot
Types Of Visual Field Testing
Amsler Grid
Types Of Visual Field Testing
Goldmann bowl perimeter
Types Of Visual Field Testing
Automated
Visual Field Procedures
Test Distance
Automated – set
Tangent Screen – 1 meter or 2 meters
Goldmann Bowl – set
Amsler Grid- 28 cm – 30 cm
Confrontation fields – 2 feet (approx 1
meter)
Patient Positioning
Forehead touching bar
Trial lens very close to the eye
Scotoma
Absolute
Brightest and largest target is unseen
Relative
Target is seen based on size and
brightness
Sphygmomanometry
(Blood Pressure Measurement)
Incidence of hypertension
Patient position
Critical Time Factors in
Measuring
How Is The Test Performed?
 Wrap the blood pressure cuff around the
upper arm about 1 inch above the bend of
the elbow
 Place the earpiece of the stethoscope into
your ears
 Place the head of the stethoscope over the
brachial artery
 Make sure that the valve is closed on the
cuff.
How Is The Test Performed?
 Inflate the cuff to approximately 20-30
mmHg (millimeters of mercury) higher than
the systolic pressure
 Open the valve slowly
 Record the number from the
sphygmomanometer when the pulse is first
heard
 This is the systolic pressure
How Is The Test Performed?
 Continue releasing the valve
 The pulse will disappear
 Record this number
 This is the diastolic pressure
 Release the rest of the air and remove the
cuff
Readings
 Normal
 The “normal” for adults is approximately
120mmHg /between 70-80mmHg
 Abnormal
 Mild Hypertension - 145-159mmHg/90104mmHg
 Severe Hypertension - 160mmHg or
more/100mmHg or more
 Hypotension - Below normal blood pressure
First Aid/CPR Emergencies
Non-ocular involvement
Fainting, seizures, CPR
Ocular involvement
Triage
Certification of Health Care Providers
Low Vision
Define legally blind
20/200 BCV or less than 200 VF in best
eye
Microscopes and magnifiers
Large Print Materials
Training
Psychological impact – patient motivation
Surgery
Refractive
PRK
LASIK
LASEK
Cataract (phacoemulsification)
Yag Laser
Posterior capsulotomy
Iridotomy
Refractive Status of the
Eye and Binocularity
(13%)
Myopia (Nearsighted)
Axial Myopia:
Axial length of eye is too
long, causing the rays of
light to come to a point of
focus before hitting the
retina.
Hyperopia (Farsighted)
Axial Hyperopia:
Axial length of eye is
too short, causing the
rays of light to come to
a point of focus after
hitting the retina.
Astigmatism
Light rays focus at
different points.
Cornea is not equal in
all meridians
football vs. baseball
Types of Astigmatism
 Simple - one ray is focused on the retina; the other is
focused either in front of (myopic) or behind (hyperopic)
 Compound - both rays are focused in front of (myopic) or
behind (hyperopic)
 Mixed - one ray is focused in front (myopic) and one ray
is focused behind (hyperopic)
 Oblique - the axis lies in a position that is not vertical
(900) or horizontal (1800)
 Irregular - cannot correct with eyeglass lens
Presbyopia
Reduction in the ability to
accommodate
Occurs normally with age
Reduction in lens elasticity
Reduction in strength of
the ciliary muscle
Refractive vs. Axial
Refractive causes of myopia, hyperopia and
astigmatism refer to the fact that the “error”
lies within the shape of the cornea and/or the
lens
Axial causes refer to the length of the eyeball
itself being the cause of the “error”
Aphakia
Absence of the crystalline lens
Cataract
Most common cause of surgical removal of
the lens
Correction
 Intraocular lens implant (IOL): Pseudophakia
 Contact lenses
 Spectacle lenses
Anisometropia
 Condition of unequal refractive state of the
two eyes
An- not
iso- same
metric- measure
Aniseikonia
Difference in the size of the two retinal
images
Inherent and acquired
Amblyopia
Reduced visual acuity
No apparent cause
Not correctable with refractive means
Strabismic - Amblyopia Ex Anopsia
Abnormal binocularity, resulting in
suppression of one eye
Refractive
Uncorrected refractive error that remains
uncorrected for a significant period of time
Eye Movements
Binocularity
Teaming of the two eyes
Versions
Parallel movement of both eyes
Ductions
Range of movement in one eye,
independent of the other eye
Eye Movements
Pursuits
Slow movement of both eye that allow for
following an object
Saccades
Rapid movement of both eyes in the same
direction
Eye Movements
Convergence
Inward movement of both eyes towards
each other
Divergence
Outward movement of the eyes
Eye Movements
Fusion
Ability of the two eyes to create one image
Suppression
Unconscious mechanism to avoid double
vision
EYE MOVEMENTS
Phorias
Latent tendency of the eye to deviate
Prevented by fusion
Occurs only when fusion is broken
Tropias
Constant deviation of the eye
Accommodation
Crystalline lens
Maintains focus as objects come closer
(accommodation)
Basic Ocular Anatomy
and Physiology
(17%)
The Globe
Three spheres or “tunics”
Fibrous
Vascular
Nervous
Courtesy: National Eye Institute, National Institutes of Health
Fibrous Tunic
Sclera
Episclera
Cornea
Courtesy: National Eye Institute, National Institutes of
Health
Vascular Tunic
Iris
Ciliary body
Choroid
Courtesy: National Eye Institute, National Institutes of Health
Nervous Tunic
Retina
Courtesy: National Eye Institute, National Institutes of Health
Orbit
Orbit
Bony socket that contains the eye
and most of the accessory organs
Seven bones
Sutures
Foramen
Sinuses
Orbital Bones







Frontal bone
Ethmoid bone
Palatine bone
Zygomatic bone
Lacrimal bone
Maxillary bone
Sphenoid bone
(Located further behind the zygomatic bone-hidden from view)
Anterior Adnexa
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Upper eyelid
Lower eyelid
Lateral canthus
Medial canthus
Caruncle
Limbus
Iris
Pupil
Puncta
Sclera
Plica Semilunaris
National Library of Medicine (NLM
Anterior Adnexa
Eyelids
Distribute the tear film across the front
surface of the eye
Protect the eye from light and debris
Reflex blinking versus blepharospasm
Lacrimal System
Lacrimal gland
Punctum
Canaliculus
Nasolacrimal sac
Nasolacrimal duct
National Library of Medicine (NLM
Tear Film Layers
Lipid
Meibomian glands
Aqueous
Lacrimal gland
Mucus
Goblet cells of conjunctiva
Cornea
First and most powerful refracting medium of the
eye
5 Layers
Epithelium (anterior)
Bowman’s membrane
Stroma (middle)
Descemet’s membrane
Endothelium (posterior)
Courtesy: National Eye Institute, National
Institutes of Health
Crystalline Lens
Nucleus
Cortex
Capsule
Accommodation
Cataract
Courtesy: National Eye Institute, National Institutes of Health
Vitreous
Gel-like substance found
in the eye (in the
vitreous chamber).
Helps to keep the
shape of the eye.
Courtesy: National Eye Institute, National Institutes of Health
Extraocular Muscles
Rectus (4)
Medial (in-adduct)
Lateral (out-abduct)
Superior (up-elevation)
Inferior (down-depression)
Oblique (2)
Superior (down & in)
Inferior (up & in)
National Library of Medicine (NLM
The Visual Pathway
Optic nerve
Optic chiasm
Optic tract
Lateral geniculate body
Optic radiations
Visual cortex
Image courtesy of Posit Science
Conjunctiva
Translucent membrane
that lines the inner surface
of the lids (palpebral) and
the outer surface of the
globe (bulbar)
Fornices - where the
palpebral and the bulbar
conjunctiva meet
National Library of Medicine (NLM)
Retina
Macula
Fovea
Cones
Peripheral retina
Rods
Optic disc
Cup
Courtesy: National Eye Institute, National Institutes of Health
Common Pathological &
Functional Disorders
Entropion
Eyelids turn inward
Ectropion
Eyelids turn outward
Ptosis
Drooping of the eyelid
Common Pathological &
Functional Disorders
Conjunctivitis
Also called “pink eye”
Inflammation of the conjunctiva
Bacterial
Allergic (contact)
Vernal (seasonal)
Giant papillary (associated with CTL wear)
Viral
Eyemaginations
Common Pathological &
Functional Disorders
Glaucoma
Characterized by increase in intraocular pressure,
increased size of optic cup and visual field defects
Chronic open-angle
Acute angle-closure
Congenital
Narrow angle
Low tension
Secondary
Courtesy: National Eye Institute, National Institutes of Health
Common Pathological &
Functional Disorders
Cataract
Opacity of the crystalline lens
Nuclear sclerosis
Cortical
Secondary
Traumatic
Congenital
Posterior subcapsular
Courtesy: National Eye Institute, National
Institutes of Health
Common Pathological &
Functional Disorders
Corneal problems
Ulcers
Dystrophy
Abrasion
Common Pathological &
Functional Disorders
Dry eye
 Also called “Keratitis sicca” or
“Keratoconjunctivitis sicca”
Pathological condition of corneal and
conjunctival dryness due to decreased
production of tears
Common Pathological &
Functional Disorders
Retinal Disorders
Detachment
Retinopathy
Diabetic
Hypertensive
Degeneration
Lattice
Macular
Macular Degeneration
Courtesy: National Eye Institute, National Institutes of Health
Ocular Pharmacology
Diagnostic agents
Therapeutic agents
Ocular Pharmacology
Mydriatic - dilates the pupil
Phenylephrine
Miotic - constricts the pupil
Pilocarpine
Cycloplegic - paralyzes the ciliary muscle
Cyclogyl
Tropicamide
Ocular Pharmacology
Routes of delivery
Solutions
Suspensions
Ointments
Courtesy: National Eye Institute, National Institutes of Health
What’s Next?
Today
Lightly review the material
Get a good night’s sleep
Arrive a little early to test
Future
Look for details about the CPOT test - begin studying
the Self-Study Course for Paraoptometric Assistants
and Technicians
Request a copy of the Practical Examination Video
from the CPC
Questions?
Study Materials
The AOA Paraoptometric Section (PS) may
assist with questions concerning PS
Membership, staff development, and study
materials 800-365-2219 ext. 4108
Certification
The Commission on Paraoptometric
Certification may assist with questions
concerning examinations, certification, and
re-certification 800-365-2219 ext. 4210