Computers and Your Eyes

One of the most common requests we get here at Vision for Life is for information about PC use and vision. And it's no wonder-almost all of us use a computer at least once in a while, and many of us sit in front of the magic box all day! In fact, the University of Iowa's Christine Sindt, O.D., estimates that Computer Vision Syndrome- or the "complex of eye and vision problems related to near work that are experienced during or related to computer use" as the American Optometric Association defines CVS - affects 75% of the people who work on computers, most markedly those over the age of 40.

If you've experienced any of the 14 symptoms listed below, you'll want to read on for information on how to combat CVS.

The American Optometric Association's 14 Symptoms of Computer Vision Syndrome

1. tired eyes
2. eyestrain
3. sore eyes
4. periodic blurred near vision
5. occasional blurred distance vision
6. headaches
7. dry eyes
8. slowness in changing the focus of your eyes
9. red eyes
10. burning eyes
11. contact lens discomfort
12. changes in color perception
13. glare sensitivity
14. excessive tearing

Obviously, the easiest way to prevent CVS is to stop using the computer! But, as that is simply not an option for the millions of us (including this writer) who make a living performing computer-related tasks, here are 5 tips to help you monitor your natural monitors: your eyes.

1. Make sure your workstation, whether on the job or at home, is set up ergonomically

"Ergonomics" is just a fancy way of saying "Being kind to your body." But as we know, being good to your body every day will benefit you in the long run. Repositioning your monitor is an easy and effective way to avoid awkward head or eye movements. As Dr. Ergo (aka Dr. James Sheedy) notes on his Web site, "Because the eyes lead the body, your body will assume whatever position is required to enable your eyes to see comfortably. A poorly located computer screen causes awkward body positions." He notes that a viewing distance of 20-28 inches is most common.

He also says that the center of the computer screen should be 4-
9 inches below your eyes, because your eyes work best with a slight downward gaze. Your computer screen and other work (and your phone, if that's part of your office) should be located straight in front of you so that you don't have to look sideways or twist your body or neck to see them.

2. Eliminate glare in your work area

Glare is an all-too-common cause of eyestrain and eye fatigue. Modifying your office lighting will eliminate glare and harsh reflections. First, find the source of the glare: Is it coming from a window, task light, or the screen itself (see #3 below)?

If possible, remove the offending source of light. Adjust blinds or curtains to minimize sunlight. Turn down overhead lights so that the brightness of the screen and the surrounding room are balanced. Do not, however, work in the dark: the contrast between computer-generated light and lack of background light strains the eyes. Task lights should be positioned to provide direct light for reading and other office work, but should not shine directly on the computer or in your eyes. You may need to use a low-wattage bulb.

You may also need to move your desk so that bright overhead lights or windows are not in your field of view. The best position for your desk is directly to the side of a window/overhead light. That way you can still enjoy some natural light without glare (caused by brightness in front of your field of vision) or reflections (caused by brightness behind you).

Another option is to use a monitor glare hood, or better yet, a screen. Look for anti-reflection screens that have been approved by the American Optometric Association.

3. Adjust your screen

Dr. Ergo notes, "Optimal contrast and visibility are attained with black characters on a white background. However, other combinations can be comfortable so long as the brightness contrast between the characters and the background is high. It is best to avoid dark backgrounds."

You can also adjust your brightness/contrast controls, and use a larger text size, as display legibility is an important factor in visual performance. For most, the size of the text should be three times the size of the smallest text you can read.

An article on "Flat-Panel Monitors Versus CRTs" in the magazine PC World says that "flat panel (LCD) displays have visual advantages compared to cathode ray tube (CRT) displays. They do not flicker and the contrast is typically higher." And because CRTs deteriorate gradually over time, you may not even realize that the picture you are looking at today is not the same one you were looking at five years ago when you bought the monitor-although this deterioration may be causing your CVS symptoms. Consider an upgrade.

4. Take a break

It's easy to lose track of time at the computer. Always remember the 10-10-10 rule and at the very minimum take a break at least once an hour for about 10 minutes and blink frequently -- video display use is associated with a decreased frequency of blinking. (And a computer break is a perfect excuse to perform your Vision for Life eye exercises.) Computer use can also cause an increased rate of tear evaporation.

5. Stay healthy

Although you can relieve dry, itchy eyes with artificial tears from the drugstore or supermarket, it's best not to rely on them. A better way to prevent dryness is to stay hydrated with good old-fashioned H2O. Of course, eating your beta-carotine-rich foods is always good for maintaining eye health, and a Japanese study suggests that supplementation with the amino acid taurine appears to alleviate vision fatigue. Contact lens wearers may want to switch to glasses during PC work, as contact lenses themselves can cause dry eyes.