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Computers and Vision
More than half of all computer operators experience
eyestrain, headaches, blurred vision and other symptoms
directly and indirectly related to increased, sustained nearpoint visual stress.
Visual stress also may underlie
complaints of general body fatigue, reduced efficiency
at work and higher error rates as the day progresses.
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Optometrists have found that most of these symptoms are
alleviated through a combination of correcting
workstation conditions, posture, stress-relieving lenses
prescribed specifically for computer operation, and in
some cases, through improving visual skills with vision
therapy.
Today, the majority of people, including children, are
computer users. If what has been learned about vision
and computers is ignored, millions will discover that
visual stress can generate serious, often permanent
vision and eye problems.
Humans have hunter-soldier eyes, essential to survival
for spotting game or danger at a distance. But during
the past half century, nearly all our work and much of
our recreation has shifted to seeing within arm's
length.
The resulting nearpoint visual stress, despite 20/20
distance visual acuity, often produces both temporary
and sometimes permanent adaptive changes, including
nearsightedness, suppressed vision in one eye, poor eye
teaming and reduced performance both at work and at
play.
Although computer manufacturers have vastly improved
their products, some computer operators find their
existing visual difficulties with nearpoint visual
activities are complicated by sometimes blurred
characters, an increase in the number and complexity of
necessary eye movements and focusing shifts, and by
sometimes poor lighting conditions, glare and
distracting reflections. Flicker also plays a role in
visual stress.
Changes in the way work is done will affect many
first-time computer users. Jobs which formerly allowed
physical movement and opportunities to look away from
near work now require extended, tiring concentration on
a computer screen image.
Many people who could handle the visual stress of
intermittent near work simply cannot deal with prolonged
nearpoint tasks. |
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| Direct Visual Signs and Symptoms |
| Headache
with/after computer use |
| Eyestrain
| Irritated eyes | Blurred vision |
| Slow
focus from screen to
distant objects |
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Losing place moving eyes from
screen |
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Difficulty seeing clearly after computer use |
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Occasional or frequent doubling of vision |
| Changes
in color perception |
| Lens prescription fails to relieve symptoms |
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| Indirect, Visually-related Symptoms |
| Neck or
shoulder tension, pain |
| Back pain |
| Excessive
physical fatigue using computer |
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Irritability increases when using computer |
| Pain in
arms, wrists or shoulders when working |
| Increased
nervousness |
| Lowered
visual efficiency |
| More
frequent visual efficiency errors |
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If you suffer from any combination of direct or indirect
conditions, it is time to have a Developmental
Optometrist evaluate your visual skills and performance.
The optometrist's recommendation may be the key to
making work less stressful, less painful, and more
productive. And, you may avoid the onset of more
permanent visual and eye conditions now observed by
optometrists among their computer-using patients
Symptoms and discomfort are the warning signs that
something must be done to reduce the possibility of
serious, permanent vision or eye problems that can alter
and diminish the quality of life.
Computer Workstation Suggestions
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Keyboard, screen and copy should, ideally, be at equal
distances from the eyes.
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Computer screens should be slightly below eye level
(about 10-20 degrees). Copy should be at the same level
as the screen.
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Locate keyboard so wrist and lower arm are parallel to
the floor or angled slightly downward.
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Chairs should provide proper back support and be
adjustable without tools by the operator.
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Adjust chair height so feet are flat on the floor with
thighs parallel to the floor.
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Adjust the worktable so legs and knees clear its
underside.
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Screen brightness and contrast should be adjusted by
the operator for maximum viewing comfort.
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Each workstation should have an adjustable shaded copy
lamp that can be aimed by the operator without causing
screen reflections or direct glare into the eyes.
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Eliminate glare and screen reflections by moving or
tilting the screen. Overhead lights may need baffles.
Try not to face toward windows or bright light sources.
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Operators should face into an open space beyond the
computer screen.
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Clean computer screen regularly; they attract and
accumulate dust.
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Adjust screen focus and image alignment frequently to
reduce visual stress.
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Vision and performance are enhanced by taking a short
break (15 minutes) every two hours. Demanding computer
workloads usually require a short change from work each
hour. Stop every 15 minutes to look up and away from the
computer to focus on a distant object. |
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