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Environmental health
Computer hazards
Originally Published: March 18, 1994 ~ Last Updated / Reviewed on: August 03, 1998
 
Alice,

What is an unhealthy amount of time to spend in front of a computer terminal? It seems like everything I do, from workstudy work to classwork to play, entails sitting in front of a computer terminal for hours on end. Any feedback on this would be much appreciated.

Going blind, sterile, or otherwise?

 

Dear Going blind, sterile, or otherwise?

Since you're still going to work and class, and presumably eating and seeing your friends, these are good signs that you are not spending all of your time in front of a computer terminal. Eye care specialists have noticed problems related to extensive use of video display terminals (VDTs). If you are farsighted, you may experience blurred vision and discomfort while using a VDT. If you have astigmatism, working at a VDT can cause aching eyes, headache, and fatigue.

Another common problem associated with computer work is repetitive stress injury (RSI), such as carpal tunnel syndrome. RSIs occur when a certain muscle or tendon is repeatedly overused or kept in an awkward position. If you spend long hours at a computer, you might want to take some of the following steps to prevent RSIs:

  • Use a firm, adjustable, and comfortable chair. Adjust chair height so that your thighs are horizontal, your feet are flat on the floor, and the backs of your knees are slightly higher than the seat of your chair. The back of the chair should support your lower back. Stretch your lower back by standing up and pulling each knee to your chest, holding that position for a few seconds.

  • Relax your shoulders. Your upper arms and forearm should form a right angle, with your wrist and hand in roughly a straight line.

  • Use the computer as you would play the piano, with fingers up and down. Don't rest your wrists and move your fingers sideways to type.

  • Position the mouse at the same height as your keyboard. When you slide the mouse around, move your entire arm and not just your wrist.

  • Take breaks of at least five to ten minutes every hour or so.

Lastly, people have expressed concern about the exposure to electromagnetic radiation from their VDTs. This is the same concern expressed about microwave ovens, cellular phones, and even high voltage power lines. It is known that these forms of radiation do have effects on health, but current research is contradictory and inconclusive about the health effects of "household" electromagnetic radiation.

"Playing" can happen off-line, too, so make sure your social life is balanced with real friends and activities -- not just virtual ones.

Alice
P.S.:
Sight Savers

  • Take frequent breaks.

  • Reduce glare and reflections -- clean your screen and block out excessive sunlight and reflections of lamps, etc., from the screen.

  • Maintain high contrast between characters and screen background -- use indirect room lighting.

  • Prevent eyestrain -- the top of your screen needs to be at, or slightly below, eye level; find a comfortable distance between your eyes and the screen (usually eighteen to twenty-eight inches).

  • Gently massage your eyes, cheeks, forehead, etc. from time-to-time to keep blood flowing and muscles loose.

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