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Ocean of knowledge #1

With so many of us using computers at work and school, computer eye strain has become a common complaint.
These problems can cause physical fatigue, decreased productivity and increased numbers of work errors.

Here are steps you can take to reduce computer eye strain and the other common symptoms of computer vision syndrome (CVS):

Use proper lighting.
Eye strain is often caused by excessively bright light either from outdoor sunlight coming in through a window or from harsh interior lighting. When you use a computer, your ambient lighting should be about half that found in most offices.

Eliminate exterior light by closing drapes, shades or blinds. Reduce interior lighting by using fewer light bulbs or fluorescent tubes, or use lower intensity bulbs and tubes. If possible, position your monitor so that windows are to the side of it, instead of in front or back.

Minimize glare.
Glare on walls and finished surfaces, as well as reflections on the computer screen can also cause computer eye strain. You may want to install an anti-glare screen on your monitor.
Again, cover the windows. When outside light cannot be reduced, consider using a computer hood.

Adjust the brightness and contrast of your computer screen.
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 the 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 — read the tips in the sidebar.
Black text on a white background is the best color combination for your eyes; other high-contrast, dark-on-light combinations are also good.

Blink more often.
Blinking is very important when working at a computer; it rewets your eyes to avoid dryness and irritation.
When working at a computer, people blink less frequently — about five times less than normally, according to studies.

Tears coating the eye evaporate more rapidly during long non-blinking phases and cause dry eyes. Also, the air in many environments is dry, which can increase the evaporation rate of your tears, placing you at greater risk for dry eye problems.

If you experience dry eye symptoms, ask your eye doctor about artificial tears for use during the day.

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.

Exercise your eyes.
A component of computer eye strain is focusing fatigue. To reduce your risk of tiring your eyes by constantly focusing on your screen, look away from your computer every 20 minutes and gaze at a distant object outside or down the hallway. Looking far away relaxes the focusing muscles inside the eye to reduce fatigue.
To ease eye strain, make sure you use good lighting and sit at a proper distance from the computer screen.Another exercise is to look far away at an object for 10-15 seconds, then gaze at something up close for 10-15 seconds. Then look back at the distant object. Do this 10 times.

This exercise reduces the risk of your eyes' focusing ability to "lock up" (a condition called accommodative spasm) after prolonged computer work.
Both of these exercises will reduce your risk of computer eye strain. Remember also to blink frequently during the exercises to reduce your risk of computer-related dry eye.

Take frequent breaks.
To reduce your risk for computer vision syndrome and neck, back and shoulder pain, take frequent breaks during your computer work day.
During your computer breaks, stand up, move about and stretch your arms, legs, back, neck and shoulders.

Modify your workstation.
If you need to look back and forth between a printed page and your computer screen, this can cause eye strain. Place written pages on a copy stand adjacent to the monitor. Light the copy stand properly. You may want to use a desk lamp, 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 the correct height.

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, which may become dry and uncomfortable during sustained computer work.

Computer glasses are also a good choice if you wear bifocals or progressive lenses, because these lenses are generally not optimal for the distance to your computer screen.


*Other Resources:

Galinsky D, et al. "Supplementary breaks and stretching exercises for data entry operators: A follow-up field study." American Journal of Industrial Medicine. 2007. Vol. 50, pp 519-527.

Lim SY, et al. "Occupational health aspects of working with video display terminals." Environmental and Occupational Medicine. 3rd ed. 1998. Philadelphia: Lippincott-Raven, pp 1333-1344.

Ashel J. "Visual ergonomics in the workplace." London: Taylor & Francis. 1998.