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I receive so
many questions from people who use
computers. They have eye symptoms and ask,
"Is it the computer or is it the work that
bothers my eyes?"
It seems that we have all traded
typewriters for computer screens. More and
more people in our population are spending
their works days or evenings looking at
the computer video display terminal (VDT)
screens. More and more people are
complaining of headaches, eye strain,
blurry vision, and a long list of other
symptoms.
The environment has changed from when our
parents worked on manual typewriters and
adding machines using the light from light
bulbs. We now work on computer (VDT)
screens using flourescent lights that
cause increased glare and increased light
sensitivity symptoms. The VDT in
everyone's workplace now places different
visual demands on people's eyes.
To understand the increase in visual
complaints of eye strain and headaches
that VDT workers experience, let's look at
the differences from our parents'
workplace.
Ink on paper from a typewriter or in a
book is seen as a solid, dark image. This
is comfortable on your eyes for reading
for prolonged periods. However, the
computer letters are not the dark, crisp
printed image that we can keep in focus.
The VDT image is blurrier and difficult to
focus on because of the depth of the
lighted image on the VDT glass screen.
There is actually depth to the VDT
computer letters, and this tricks our eyes
into constantly focusing a little bit "in
and out." This makes the eyes work a
little harder attempting to "auto-focus"
over the entire work day. This brings on
the increased symptoms.
One of the most commonly asked questions
is, "Are computer video display screens
(VDTs) harmful to my eyes?"
I am glad to tell you the answer is no.
Extensive private and government research
studies have not shown any evidence that
VDTs are harmful to your eyes. But totally
aside from the question of being harmful
or damaging to the eyes is the question of
physical discomfort. Most complaints,
which include visual discomfort, eye
strain, eye irritation, back aches and
pain of a muscular nature, have been found
to be associated with work place posture
and the total ergonomics of the eyes,
head, neck and seating posture.
Much of the eye strain and symptoms is
usually caused by poor lighting, improper
placement of the reading supplies,
computer screen or keyboard. We have found
that the type of lighting used in the
office and the level of reflection from
work surfaces can be changed to improve
the comfort of employees. Computer users
have the capability to reduce fatigue on
their eyes by getting filters or tints in
their eyeglasses, by getting glasses
specifically for computer use, or by
getting coatings or filters on their VDT
screens at work.
Here is a check list to evaluate your
computer situation:
1. The top of the VDT screen should be
placed slightly below eye level.
2. Your reference material should be
placed on a document holder and moved
close enough to the screen so that you do
not have to swing your head and eyes back
and forth from your material to the VDT
screen. Otherwise, your eyes are
constantly changing focus, and your
muscles can become stiff and sore, and
your eyes can fatigue quicker, causing eye
strain and headache symptoms.
3. Try adjusting your lighting to
eliminate or decrease glare and harsh
reflections. If office lighting or window
shades can not be modified, hoods or VDT
filters may decrease the problems.
4. A frequent break in eye usage by simply
glancing out the window or looking 20 feet
away will help. Simply standing up and
stretching in place for 5 seconds will
reduce fatigue.
5. Research shows that working on a
computer reduces normal blinking by half,
from 20 times a minute, to 10 times a
minute. To keep the eyes from drying out
and feeling hot, tired and itchy, try
blinking more rapidly every once in awhile
or occasionally closing your eyes for a
few seconds, alternating with the looking
at a distant object.
6. Anyone with diagnosed dry eyes would
benefit from using artificial tears
occasionally (or frequently) combined with
the above recommendations.
7. Get a good check-up from your
optometrist or family eye doctor if
problems persist, since the proper
prescription or computer vision lenses may
be needed for the most comfortable vision.
It is reported that more than 20 million
workers in America experience VDT eye
strain. As mentioned, other factors to
help relieve the strain include adjustment
of your chair's height to allow your feet
to reach the ground and rest comfortably.
Also, your keyboard should rest below your
desktop, if possible. And try to insure
that your wrists have proper supports.
In summary, the VDT computer screen is
here to stay, and you must do a few things
to help yourself remain comfortable while
at work or having fun on your computer. |
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Dr. Mark
Sibley
Dr. Mark
Sibley, M.D., F.A.C.S., is a Board
Certified Ophthalmologist and laser
specialist who practices locally. He is
medical advisor to the Society to Prevent
Blindness and to the American Diabetes
Association, and is team ophthalmologist
for the Devil Rays. |
