Beth Barstow PhD, OTR/L, SCLV
UAB Department of Occupational Therapy
Low Vision Graduate Certificate Program
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By the end of the session, participants will
understand the prevalence and characteristics of
older adults with low vision.
By the end of the session, participants will be able to
state the primary conditions, visual deficits and
behaviors of older adults with low vision.
By the end of the session, participants will be able to
describe basic intervention strategies to enhance
performance of older adults with low vision.
By the end of the session, participants will be able to
describe referral sources for older adults with low
vision.
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A visual impairment severe enough to
interfere with occupational performance but
allowing some usable vision
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Blindness
◦ Persons who are blind have no light perception and
no capability to use vision
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Persons with low vision are not blind but they
do not see well either
◦ They inhabit a gray area between having good
vision and no vision
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Term coined by federal government to
describe visual impairment criteria
qualifying persons for benefits and services
To be legally blind person must have
◦ Best corrected visual acuity of 20/200 or less in
the better eye or
◦ A visual field of 20 degrees or less in the better
eye
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Low vision describes the visual functioning of
someone for whom regular eyeglasses or
medical procedures cannot correct vision to
within the normal range
Legal blindness is eligibility criterion used to
qualify persons for services
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Persons who are defined as legally blind have
varying degrees of vision loss
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Persons who are blind are also included in the
definition of legal blindness
◦ But blindness is NOT synonymous with legal blindness
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Many persons who have low vision but who are not
legally blind have significant limitations in
occupational performance
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World Health Organization
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More than 161 million people visually
impaired (2002)
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124 million people with low vision
37 million were blind
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Most persons with low vision grew up,
worked, reared their families and retired as
sighted persons
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Most low vision is caused by just 3 agerelated diseases
◦ Macular degeneration
◦ Glaucoma
◦ Diabetic retinopathy
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Prevalence of the diseases increases with
each decade over age 60
Account for 90% referrals to low vision
clinics
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Age-related
◦ Incidence increases with age
◦ 1 out of 4 in the plus 80 age group
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Vision loss is permanent
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Chronic and progressing
◦ Treatment focuses on management/prevention of
further vision loss NOT cure
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Age is the best predictor of who will develop
low vision
◦ 2/3rds of persons with LV are over 65 years of
age
◦ Incidence reaches 25% for adults over 85
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Older adults associate low vision with aging
◦ Because they see it as consequence of aging they
don’t seek out rehab
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2/3rds of older adults with low vision will have at
least 1 other chronic condition limiting ADLs
When low vision combines with other chronic
diseases it can significantly increase the
likelihood of disability
 Low vision plus diabetes= 6x greater likelihood of having
difficulty shopping and socializing
 Low vision plus CVD= 7x greater
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Increased risk of depression with older-adults
who have low vision.
◦ 2 to 5 times more likely to develop depression
◦ Greater than other common age-related conditions
◦ 25-30% experience clinically significant symptoms of
depression
◦ About 7% of older-adults with a visual impairment meet
the criteria for major depressive disorder, according to
the Diagnostic and Statistical Manual for Mental
Disorders
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Someone who has a minimal impairment is
just as likely to develop depression as
another with severe impairment.
Increased probability of depression in older
adults who are legally blind in one eye.
◦ Impairment in one eye may produce uncertainty and
apprehension about future visual abilities and
possible ongoing changes.
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Ratio of elderly women to men is 2:1
◦ Largest number of older adults with low vision are
women in their mid-80’s
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Women with vision loss are more likely to live
alone without in-home support
◦ 75% of older men with low vision are married and
have in home support compared to 30% of women
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African Americans, Hispanic, Native Americans,
Pacific Islanders experience higher rates of age
related vision loss
 African Americans 5x more likely to experience glaucoma
 6x more likely to experience blindness
 Experience higher rates of diabetic retinopathy
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Despite age and impairment 70% of older adults
with low vision live in their own home
27% of nursing home residents age 65 and older
have a visual impairment ( National Nursing Home Survey, 1997)
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Age-related macular degeneration
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Diabetic retinopathy
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Glaucoma
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Progressive chronic eye condition affecting the
macular area of the retina
Macula located in the central twenty degrees of the
visual field is composed primarily of cone cells
responsible for providing information regarding
the color, contrast and detail of objects
Slit lamp image of healthy retina
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Slit lamp image of retina with AMD-yellow areas indicate dead
retinal tissue-areas of scotoma
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Affects an estimated 1.75 million people in
the U.S.
(EDPRG , 2004)
Estimated that incidence will rise to over 3
million by the year 2020
(EDPRG, 2004)
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Dry (atrophic)- light sensitive cells in the
macula slowly breakdown
Wet (exudative)- abnormal blood vessels
behind the retina start to grow under the
macula
(NEI, n.d.)
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Specific cause is unknown; theories include
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genetic predisposition
lack of anti-oxidants
cholesterol build up in the eye
abnormal response to inflammation
(University of Alabama at Birmingham Department of
Ophthalmology [UABDO], 2007)
Modifiable
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Smoking
Elevated plasma
cholesterol
Hypertension
High body mass index
Atherosclerosis
Diet high in fat and low
in antioxidants
(Guyner & Wei-Tinn
Chong, 2006)
Non-Modifiable
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Age
Race
Gender
(NEI, 2011)
Causes:
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macular scotomas
photophobia and glare sensitivity
fluctuating vision
slow dark/light adaptation
reduced contrast sensitivity
reduced color identification
reduced visual acuity
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National Eye Institute
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Difficulty with activities requiring ability to
see:
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Detail
Color
Low contrast
Manage bright light and glare
Adapt to fluctuating light levels
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Major cause of
vision loss is
damage done by
persistent high
blood glucose to
the small blood
vessels of the
retina
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Retinal blood vessels
leak, or become
blocked, impairing
vision over time
If abnormal new
blood vessels grow
on the surface of the
retina, serious
damage can be
caused
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Diabetes
Length of time you’ve
had diabetes
◦ Age related because
the longer one has
diabetes, the more
likely will experience
DR
Non-modifiable
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Undiagnosed diabetes
Maintain stable and
controlled blood glucose
levels
◦ 120
◦ Avoid spikes in levels
◦ Requires strict
adherence to diet and
glucose monitoring
Lower blood pressure
Exercise
Engage in heart healthy
lifestyle
Modifiable
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Diabetic retinopathy and other eye
complications associated with diabetes can
be prevented with good control of blood
glucose levels, blood pressure levels and
regular eye care
◦ Finding from the Diabetes Control and
Complications Trial (DCCT)
 A 10 year study ending in 1993 involving 1400
subjects
 Showed that keeping blood glucose levels as near to
normal as possible reduced damage to eyes by 75%
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Requires
◦ Regular monitoring by physician to ensure optimal
blood glucose & blood pressure management
◦ Adherence to healthy eating, exercise and
medication management, lifestyle modification
important
◦ A team approach to diabetes self-management is
important, including a variety of health care
providers
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Two types: background and proliferative
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23.4 million people have diabetes (type 1 or 2)
8% of population
 1 million new cases per year
 7th leading cause of death in U.S.A.
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7 million are adults over 65
 20% of older population
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Higher incidence among African Americans, Native
Americans, Hispanics, Pacific Islanders
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Alabama leads country with highest rate of type 2
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Leading cause of visual impairment &
blindness in persons in the industrialized
world in persons between the ages of 2574
Nearly ½ of persons with diabetes will
develop some degree of diabetic
retinopathy during their lifetime (Roy et al., 2004)
◦ 21% of newly dx type 2 persons will already have
developed some diabetic retinopathy
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Most prevalent diabetic eye complication
Despite efforts towards PREVENTION,
persons with T1D and T2D (BOTH) are
susceptible to diabetic retinopathy
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Reduced acuity
Reduced contrast sensitivity function
Sensitivity to glare
Macular scotomas
Peripheral field loss
Night vision reduced
Reduced color discrimination
Double vision (diplopia)
Visual fluctuation
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National Eye Institute
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Difficulty with activities requiring ability to
see:
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Detail
Color
Low contrast
Manage bright light and glare
Adapt to fluctuating light levels
Peripheral visual field
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Collection of diseases that affect the optic
nerve
◦ Open angle is the most prevalent type in older
adults
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Called “the silent thief of sight”
◦ Few noticeable symptoms until very advanced
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2.2 million Americans
(Eye Disease Prevalence Research
Group, 2004)
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Begins in anterior chamber of the
eye
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Pathogenesis
◦ Normally the rate of aqueous
production equals rate of outflow and
pressure within the eye is maintained
between 9-21mm Hg
◦ In glaucoma increase in IOP occurs
from build up of aqueous humor in
anterior chamber
◦ Only outlet for pressure is optic disc
◦ Builds up pressure along optic nerve
and decreases blood flow to nerve
 Causes permanent damage to optic nerve
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Pathogenesis of Glaucoma
Problem starts here
Damage occurs here
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Multiple causes
◦ Over-secretion of aqueous by ciliary body
 Exceeds capacity of trabecular meshwork in Canal of
Schlemm
 Rare
◦ Anatomical aberration resulting in narrow angle
between iris and cornea preventing efficient drainage
of aqueous
 Rare
◦ Scar tissue from an inflammatory process or surgery
obstructs the drainage of the aqueous through the
trabecular meshwork
 Most common cause
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Characterized as closed or open angle depending
on location of the compromised aqueous drainage
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Can be congenital or acquired
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May manifest as a primary or secondary condition
◦ Primary glaucoma occurs without previous pathology
◦ Secondary occurs secondary to an inflammatory process
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Any form can lead to blindness
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Ethnicity- African-Americans, Hispanics and
Asian
Over age 60
Genetic predisposition
Steroid users
Eye injury
Hypertension
Myopia
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Peripheral field loss
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Can be sensitive to light and glare
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Advanced- central field loss resulting in
reduced acuity, contrast sensitivity function,
color discrimination
National Eye Institute
Difficulty with activities requiring ability to see:
◦ Peripheral visual field
 Mobility
 Attending to the larger environment
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Low vision creates difficulty seeing small visual
details, low contrast and color
Can add other challenges like sensitivity to glare &
difficulty adjusting to changing light levels, even
seeing things that aren’t there (called phantom vision)
Affects a variety of vision-dependent basic and IADLs
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Ensure lighting is optimal for task
performance
Use contrast to increase visibility of key
objects and landmarks
Minimize background pattern
Magnify and enlarge
Organize
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Even illumination
◦ No surface shadow
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Maximum lumens/power
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Minimum glare
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Flexible placement
◦ To get optimum positioning
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Most commonly used but
often least effective
Advantages
◦ Cheap
◦ Available in many forms
◦ Design allows for
optimal placement
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Disadvantages
◦ Glare
 Bulbs put out predominantly yellow light that scatters
more on the retina
◦ Spotlight effect occurs if shade is used over bulb
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Best for overhead
lighting
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Advantages
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Disadvantages
◦ Provides even
illumination
◦ Newer models give
soft light without strobing
effect
◦ Some persons are sensitive to
strobing effect
◦ Limited flexibility in placement
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Used for task and room
lighting
Torchiere lamp
Advantages
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High quality light
Minimum glare
Even illumination
Energy efficient
Reading lamp
Disadvantages
◦ Hot light
◦ Reduces flexibility in
placement
 Must avoid flammable
materials
 Can’t place too close to
client
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Combines all colors of spectrum to provide
pure white light; very similar to natural sunlight
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Advantages
◦ High quality light
◦ Non glaring
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Disadvantages
◦ Not as readily available in
all stores
◦ More expensive than other
bulbs
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Always behind
person if possible
Eliminate shadows
on surface
As close to task as
person can
tolerate
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Milk in a black cup
Yarn placed against a dark blue
lap blanket to increase visibility
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Place setting without contrast
Place setting with contrast
Reversible black and white cutting board
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Use dark measuring cups
for flour, sugar and light
for molasses, brown sugar,
vanilla. Mark increments on
pyrex cup with bright orange
high marks.
Bright red tape used to mark
handle on tea kettle
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Like static on a radio, makes it more difficult
to locate item needed
Use solid colors on background and support
surfaces
Eliminate clutter
When you can’t eliminate pattern, increase
contrast of key structures
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Use solid color for background surfaces
Note increased
visibility with
plain background
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Reduce and eliminate clutter
Cluttered junk drawer
Organized, clutter free utensils
hanging on a grid
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Magnifying
mirrors
Chest magnifier
Big Eye magnifier
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No organization
Items grouped by type on
separate shelves; handles
marked with contrasting tape
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Sources:
Arditi, A. (Making text Legible: Designing for people with partial sight
http://lighthouse.org/accessibility/legible/
Kitchel, E. (APH Research: Large Print Guidelines
http://www.aph.org/edresearch/lpguide.htm
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More susceptible to changes in text quality
◦ Letter size, contrast, spacing, color of text, color of
page and text luminance
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Readers with normal vision can tolerate poor
quality print and read in low lighting BUT…
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Enlarge text size as much as possible
◦ Most persons prefer to read at print sizes 3-5
points greater than their minimum resolution
◦ Minimum print size should be 16-18 points or
larger
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Maximize print contrast
◦ Normally sighted persons can tolerate a significant
reduction of contrast and still resolve print but low
vision readers cannot
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Avoid all color contrasts but black and
white
◦ Red and white or blue and white is less visible
Some indication that low vision readers do best with
White on black
But
Black on White
is more familiar and esthetically pleasing
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Avoid condensed font
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Choose font with increased spacing
between words
◦ Assists person to find beginnings of words
The cow jumped over the moon….(Arial)
The cow jumped over the moon…(Courier)
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Avoid superfluous font styles
Serif
Times roman font
Sans Serif (block)
Geneva font
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Bolded typeface is more readable
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Use familiar typeface
◦ Combination upper and lower case letters (Mixed
Typeface) is more readable than
 ALL CAPS
 Slanted Text
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Line spacing
◦ A minimum of 1.25 spaces between lines
◦ or 25-30% of the point size
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Make headings larger and bolder to set them
apart from the text
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No columns
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No divided words
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Use extra white space to separate sections
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Extra wide binding on reading material makes it
easier to lay the magnifier flat on the surface
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Avoid glossy paper
◦ Reflects light off of page and creates glare
White, ivory, cream or yellow colors-avoid
dark colored paper
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High quality full color or black line art
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Avoid shaded drawings
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Don’t overlay print on graphic
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Ophthalmologists
Optometrists
Orientation and Mobility Specialists
Certified Vision Rehabilitation Therapists
Certified Low Vision Therapists
Teachers of Visually Impaired
Occupational Therapists
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