With so many
people using computers at work, eyestrain has become one of the leading
office-related health complaints.
Experts
estimate 50% to 90% of computer users experience some degree of eyestrain or
other symptoms of computer vision syndrome (CVS) during their work day. Studies
show eyestrain and CVS often cause fatigue, decreased productivity and more
work errors.
So what can
you do about it? Here are steps you (and your employer) can take to reduce
computer eye strain and the other common symptoms of computer vision syndrome
(CVS):
1. Get a
computer eye exam.
This is the
most important thing you can do to prevent computer vision problems. According
to the National Institute of Occupational Safety and Health (NIOSH), computer
users should have an eye exam before they start working on a computer and once
yearly thereafter. Be sure to tell your eye doctor how often you use a computer
at work and at home.
2. Use
proper lighting.
Computer
eyestrain is often caused by excessively bright ambient lighting — either from
outdoor sunlight coming in through a window or from harsh interior lighting.
For the most comfortable computer use, ambient lighting should be about half as
bright as that found in most offices.
If possible,
reduce the brightness of interior lighting by using fewer fluorescent tubes in
overhead light fixtures or use lower intensity bulbs. If possible, position
your monitor so that windows are to the side of it, instead of in front or
back. Adjust window blinds to reduce the amount of sunlight entering your
workstation.
3.
Minimize glare.
Glare on
walls and finished surfaces as well as reflections on the computer screen can
also cause computer eyestrain. You may want to install an anti-glare screen on
your monitor and, if possible, paint bright white walls a darker color with a
matte finish.
Again, cover
the windows. When outside light cannot be reduced, consider using a computer
hood.
If you wear
glasses, have an anti-reflective (AR) coating applied to your lenses. AR
coating reduces glare by minimizing the amount of light reflecting off the
front and back surfaces of your eyeglass lenses.
4.
Upgrade your display.
If you've
not already done so, replace your old tube-style monitor (called a cathode ray
tube or CRT) with a flat-panel liquid crystal display (LCD), like those on
laptop computers.
LCD screens
are easier on the eyes and usually have an anti-reflective surface.
Old-fashioned CRT screens can cause a "flicker" of images on the
screen. Even if this flicker is imperceptible, it can still contribute to
eyestrain and fatigue during computer work.
If you still
use a CRT, you can decrease eyestrain from flicker by increasing the refresh
rate of your screen to 75 hertz (Hz) or higher. You can access this setting in
the Control Panel of your computer.
When
choosing a new flat panel display, select a screen with the highest resolution
possible. Resolution is related to the "dot pitch" of the display.
Generally, displays with a lower dot pitch have sharper images. Choose a
display with a dot pitch of .28 mm or smaller.
Finally,
choose a relatively large display. For a desktop computer, select a display
that has a diagonal screen size of at least 19 inches.
5. Adjust
the brightness and contrast of your computer screen.
For more
comfortable viewing, adjust the display settings on your computer so the
brightness of the screen is about the same as your work environment.
As a test,
try looking at the white background of this web page. If it looks like a light
source, it's too bright. If it seems dull and gray, it may be too dark.
Also, adjust
your screen settings to make sure the contrast between the screen background
and the on-screen characters is high. And make sure that the text size and color
are optimized for the most comfort. Usually, black text on a white background
is the best color combination. But other high-contrast, dark-on-light
combinations may also be acceptable.
6. Blink
more often.
Blinking is
very important — it rewets your eyes to keep them moist, comfortable and clear.
Studies show
that, during computer use, most people blink only about 20% as frequently as
they normally do. This greatly increases the risk for dry eyes, blurred vision,
eye irritation and fatigue.
To keep your
eyes comfortable and seeing well during computer use, try this exercise: Every
20 minutes, blink 10 times by closing your eyes as if falling asleep (very
slowly). This will help rewet your eyes.
Also, keep a
bottle of artificial tears at your workplace and use them to moisten your eyes
often during prolonged computer use. Ask your eye doctor to recommend the best
brands for your needs.
7.
Exercise your eyes.
Another
cause of computer eyestrain is focusing fatigue. Research shows that it's
harder for our eyes to maintain focus on computer-generated images than on
printed images in a book or magazine.
To reduce
your risk of focusing fatigue during computer use, look away from your screen
or monitor every 20 minutes and gaze at a distant object across the room.
Looking far away relaxes the focusing muscles inside your eyes, reducing
focusing fatigue.
Another
exercise is to look far away at an object for 10-15 seconds, then gaze at
something up close for 10-15 second--then look back at the distant object
again. Do this 10 times. This exercise reduces the risk of your eyes' focusing
system from "locking up" (a condition called accommodative spasm)
during prolonged computer work.
8. Take
frequent breaks.
Take
frequent, short breaks from your computer work throughout the day. Stand up,
walk away from your work station and stretch your arms, legs, back, neck and
shoulders. These activities will reduce your risk for computer vision syndrome
and neck, back and shoulder pain.
Many workers
take only two 15-minute breaks from their computer during their work day.
According to a recent NIOSH study, computer workers experienced significantly
less discomfort and eyestrain if they took four additional 5-minute
"mini-breaks" during the day.
Interestingly,
these supplementary breaks did not reduce productivity. Data entry speed was
significantly faster as a result of the extra breaks, so work output was
maintained even though the workers had 20 extra minutes of break time each day.
9. Modify
your workstation.
Looking back
and forth between a printed page and your computer screen (as during data entry
tasks), can also cause eyestrain. To improve comfort during these tasks, place
the print material on a copy stand adjacent to your screen or monitor. If
necessary, use a desk lamp to illuminate the print material--but make sure it
doesn't shine into your eyes or onto the computer screen.
Improper
posture during computer work also contributes to computer vision syndrome.
Adjust your workstation and chair to a comfortable height so your feet are flat
on the floor in front of you.
Adjust your
chair and computer so your screen is approximately 20 to 24 inches from your
eyes and slightly below eye level so you can view it comfortably with your head
and neck in a natural position.
10.
Consider computer eyewear.
For the
greatest comfort at your computer, you may benefit from having a customized
eyeglasses prescription for your computer work. This is especially true if you
normally wear contact lenses, that can become dry and uncomfortable during
sustained computer work.
Computer
glasses are also a good choice if you normally wear eyeglasses with bifocal or
progressive lenses. Though these lenses provide excellent vision for most
tasks, they don't provide an adequate viewing zone for prolonged computer work.
Your eye
doctor can prescribe specially-designed computer eyewear to give you the best
possible vision at your computer screen. Keep in mind that computer glasses
are a specific type of eyewear and typically should not be worn when driving.
For more
information on computer glasses and computer vision,
visit All About Vision®.
Article
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