Use computers? You may have CVS

Last Updated 16 November 2012, 13:01 IST

Regular computer use can lead to eye and vision problems, says Dr Sri Ganesh

A terrible headache, redness and dryness in the eyes, persistent pain in the neck, back and shoulders … these are not signs of aging but common problems that adults, and even young children, face today. You can blame it on the dependency on electronic gadgets like computers and laptops.

We neglect the minor pains thinking they are due to stress, a migraine or work pressure, but the underlying problem which has grown rapidly across the metros is Computer Vision Syndrome (CVS), a complex of eye or vision problems which are experienced during, and are related to, computer use.

The eyes are the most delicate parts of the body. Staring at the brightly-lit computer screens for hours at a stretch is adversely affecting the eyesight of people across the globe. This health condition most commonly occurs when the viewing demand of the task exceeds the visual abilities of the video display terminal (VDT) user. CVS is caused by our eyes and brain reacting differently to characters on the screen than they do to printed characters.

Working at a computer terminal requires focus on the computer screen. Prolonged viewing is the most common cause of CVS. Staring at a computer screen is unnatural for the human optical system.

Working for long durations in front of the screen requires a lot of effort and is challenging for the eyes. Blinking is very important when working at a computer — it re-wets your eyes to avoid dryness and irritation. When working on a computer, people blink less frequently. The human eye normally blinks approximately 14 times per minute but when we use the computer the blinks are limited to 4 to 6 times per minute. Lower blinking rates cause eye moisture to evaporate and this is generally referred to as dry eye.

Dry eye causes people to arch their foreheads in an effort to see better, thus causing headaches. The awkward, unnatural postures, lead to sore backs, stiff necks and hurting shoulders. Aches and pains are often caused by trying to read the screen through the lower portion of bifocals, or though half-eye reading glasses. You tip your head up or lean forward to see, and this unnatural posture makes you sore.

Computer eyeglasses make the screen look clearer because they eliminate the constant refocusing effort that the eyes go through when viewing the screen. It has also been clinically proven that having the correct prescription in computer eyeglasses increases productivity and accuracy. If you work in a brightly lit office, you may benefit from a light tint applied to your computer lenses. This can cut the amount of light that reaches your eyes and provide relief in some cases. But tints and filters don’t address the underlying cause of computer eyestrain.

Some important steps that can be taken to safeguard your eyes from CVS are: use of proper lighting, minimising the glaze and brightness of the computer, improving the quality of your monitor display etc.

More than 70 per cent of computer users need computer eyeglasses according to a study performed by the University of California, Berkeley. Twenty five per cent to 30 per cent of children would benefit from computer eyewear.

Ergonomics is a vital aspect of safeguarding your eyes from CVS. Changing one’s computer workstation can certainly help to minimise other physical symptoms. But ergonomics cannot fix a visual problem. The proper prescription computer eyeglass at the proper computer distance (18” to 28”) is the most important. This can be done only with the right computer lens prescription. Place your monitor directly in front of you, not off to one side (it should be about 20 to 26 inches away from you).

Make sure your monitor is not too high. CVS expert, Dr James Sheedy,  recommends that the centre of the screen be four to nine inches below your straight-ahead gaze. If you reposition your chair, keep in mind that your arms should be parallel to the floor when you type, and your feet should be flat on the floor (or a footstool).

Keep contrast and brightness at moderate levels and reduce your screen glare. Make it a point to blink rapidly. Blink 10 times by closing your eyes as if falling asleep (very slowly). This will help re-wet your eyes. Do this every 30 minutes and take frequent breaks. Exercise your eyes whenever possible.

(The writer is Chairman and Managing Director of Nethradhama Hospital, Bangalore.)

(Published 16 November 2012, 13:01 IST)

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