Curse in the blessing

From the CEO of a company to a child in school, everyone uses computers. However, our reliance on computers is affecting our physical and mental well being and ultimately affects our productivity.

What is computer vision syndrome?

The American Optometric Association defines it as a complex of eye and vision problems related to computer use.

If you use the computer, you probably have experienced one of these symptoms at some point or the other.

- Headache
- Burning, red, eyes
- Dry or sore eyes
- Sensation of “sand in the eyes”
- Watering of eyes
- Inability to maintain focus
- Letters on screen running together
- Blurred vision or double vision

Computer vision syndrome occurs due to a combination of factors.

Pixels vs. Print: Human eyes are good contrast detectors and respond well to images which have well defined edges with good contrast between the letters and background. Therefore eyes respond well to printed text material that consists of solid black letters on white background. In contrast, electronically generated pixels are brightest in the centre with the brightness decreasing towards the edges. Our eyes respond to the indistinct edges by reverting to a point in space where the eye muscles rest. This constant movement of the eye muscles causes eye strain and fatigue.

Lighting and glare: Glare from computer and surroundings like fluorescent lights, bright outdoor lights; highly reflective surfaces can cause eye strain.

Improper workstation: Improperly positioned workstation can cause awkward body posture and eye strain. We are visually directed creatures and hence will alter our body position to see things clearly. Computer placed higher than our eye level  forces us to keep our eyes wide open and blink less and can cause neck, shoulder and back pain.

Reduced blinking: Blinking keeps the eye wet and allows a fresh tear film to coat the eye surface. It allows the eye to rest for a few seconds. We normally blink 15-20 times a minute. During computer use, we tend to blink just 4-5 times per minute. Dryness of the eyes can lead to redness, pain, burning and foreign body sensation in the eyes. Slow refocusing: When our eyes continuously focus on near objects like the computer screen for long hours, our eye muscles begin to adapt to that range of vision. When we need to look at a distant object the muscles in the eye have difficulty in relaxing and distant objects appear blurred for a few seconds.

Corrective measures

- Eye examination: All computer users should have an eye examination to correct any refractive errors and to detect and undiagnosed eye conditions.

Proper lighting and reduce glare - Good light distribution is very important and is accomplished when all objects in the room have equal brightness.

- Use blinds or curtains to eliminate bright exterior light. Avoid bright fluorescent lights in offices. Most offices have too much ambient light around 75-150 foot candles.
Recommended light in offices where computers are used should be 18-46 foot candles.
Anti-glare screens can be installed on monitors to reduce visual discomfort.

- Blink - Try to blink more often. Since blinking is an automatic reflex, it may take some effort and concentration to make sure you blink constantly while working.
- Artificial tears: Artificial tears or ocular lubricants are eye drops that can be used regularly to prevent dry eyes.

- Break: Your eyes need to focus at different distances regularly to relax the eye muscles. It's a good idea to follow the 20/20/20 rule i.e., every 20 minutes look at an object 20ft away for 20 seconds. Alternately, close your eye for a few seconds. This not only relaxes your eye muscles but it also rewets your eyes.
- Adjustment of your workstation:  Computers should be placed 20-28 inches (50-60cms) in front of your eyes so that it is comfortable for both your eyes and body. The top of the monitor should be at your eye level because your eyes work best with a slight downward gaze.