Computer vision syndrome
Computer vision syndrome
Over the last twenty years, the pace of advance in electronic technology has been breathtaking. From the first limited-use personal computers and their fuzzy-imaged information exchange monitors (also known as CRTs and VDTs), the industry has evolved to offer faster chips, more capable software, higher storage capacity, the promise of the Internet with on-line living and the tease of a paperless society.
The change in capability has been rapid and massive, but the
information exchange medium for the computer user has evolved only a
little. Now, we view slightly less fuzzy VDT monitors and liquid
crystal display (LCD) screens, which are still not at all friendly
to the human visual system. Twenty years ago, optometrists began to
hear the first murmurings of vision-related complaints from their
computer-using patients. Today, we hear the same array of symptoms
from a great many more patients, but we give the impression to be no
closer to a good set of reliable answers.
Computer vision syndrome (CVS) is a term that describes
eye-related problems and the other
symptoms caused by prolonged computer use. As our dependence on
computers continues to grow, an increasing number of people are
seeking medical attention for eye strain and irritation, along with
back, neck, shoulder, and wrist soreness.
These problems are more noticeable with computer tasks than other near work because letters on the screen are formed by tiny dots called pixels, rather than a solid image. This causes the eye to work a spot harder to keep the images in focus.
Causes:
The people normally blink less when working on computer and blinking
is necessary to keep eyes moist and relaxed. Less blinking causes
excess of evaporation and dry eye.
Some people also have minor problems such as eye coordination and
focusing that aren't apparent in other activities, but become an
issue when using the computer.
Computers are often set up in ways that make eyes work too hard.
The computer typeface may be too small
The glare from nearby lights or windows may be too bright
The monitor may be placed higher than is natural for your eyes.
People over 40 with bifocals or reading glasses
often run into problems because their glasses are geared to looking
at books held 16 inches away, rather than computer screens that are
typically two feet away.
Pathophysiology:
CVS is caused by decreased blinking reflex while working long hours
focusing on computer screens. The normal blink rate in human eyes is
16-20 per minute. The blink rate to decrease to as low as 6-8
blinks/minute for persons working on the computer screen. This leads
to dry eyes. Additionally, the near focusing effort required for
such long hours puts strain on ciliary muscles of the eye. This
induces symptoms of asthenopia and leads to a feeling of tiredness
in the eyes after long hours of work. Some patients present with
inability to properly focus on near objects after a short duration.
This can be seen in people aged around 30-40 yrs of age, leading to
a decrease in the accommodative focusing mechanisms of the eye. This
can be a setting for early presbyopia
Symptoms:
1. Eyestrain
2. Blurred vision
3. Dizziness or nausea
4. Headaches
5. Red, dry or burning eyes
6. Increase in nearsightedness
7. Change in color perception
8. Slow refocusing
9. Excessive fatigue
10. Neck, shoulder and
back pain
11. Eye-teaming problems and/or occasional double vision.
Preventive steps:
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If you have trouble with your eyes when computing, follow the preventive measures which can give you relief from most of the symptoms:
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Position your monitor 16 to 30 inches away from your eyes, depending on what's comfortable.
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It should be four to eight inches lower than eye level, so you're look- slightly down towards it. And it should be tilted slightly up, as if it were a book or magazine. Looking down covers more eye and so tear evaporation from exposed surface is less.
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Place light sources perpendicular to your computer, so they won't shine in your eyes or reflect on your screen. If you have a glare problem, consider installing a glare screen or a three-sided hood on your computer.
Use a large enough typeface. Experiment with
different fonts and background colors to see if one is easier for
you to read.
Adjust your monitor for the most contrast that you are comfortable
with.
Make efforts to blink frequently.
Take short breaks that are look away from the screen or close the
eye periodically for few seconds / minutes.
In persons above 40 who are using bifocals will need special glasses
for computer work.
Treatment:
1. Use of artificial tears or contact lens wetting solution to keep
your eyes moist gives relief from symptoms.
2. People with moderate to severe eyestrain or fatigue may need
glasses.
Dr. Makbul G. Mansuri
M.S. (Ayu.) Shalakyatantra,
Lecturer Shalakyatantra,
J.S. Ayurved College,
NADIAD-387001 (Guj.)
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