If you spend more than 2 hours a day peering at a computer display, you have at least a 50-50 chance of experiencing vision problems or other physical ailments related to your PC use. That's according to Dr. Wendy Strouse Watt, O.D., in her 2003 article Computer Vision Syndrome and Computer Glasses.
The advent of flat panels may have minimized the risk somewhat, but most office workers now spend more time each day at a computer than they did at the time of the study. In a series of articles on Computer Vision Syndrome, the American Optometric Association (AOA) highlights the extent of the problem.
The association quotes the results of a survey of optometrists that estimates 10 million "primary" eye examines occur annually in the U.S. due in large part to use of computer displays. The AOA reports that computer users are more likely to complain of vision-related problems than to experience wrist pain and other musculoskeletal maladies.
You'll find plenty more about the causes of computer-related eyestrain in those two articles, as well as in this comprehensive article on the eMedicine site. More important for most of us PC users is the advice the articles offer for treating and avoiding health problems resulting from long hours using a PC. Here's a quick summary of the best ways to prevent and overcome ailments caused by extended computer use.
Get the angle-of-vision right
The AOA recommends a viewing distance from 20 to 28 inches, depending on the size of the text and the limitations of the workstation. Equally important is the viewing angle: the top of the monitor should be slightly lower than eye level so the viewer is looking down at an angle of about 15 degrees. Tilt the monitor up 10 to 20 degrees from vertical.
The eMedicine article features a pop-up diagram that lets you determine the optimum viewing angle based on a mathematical equation. The information is clearly intended for eye-health professionals, but the diagram certainly is precise.
Adjust the lighting
More accurately, adjust the glare level. Dr. Watt's article recommends that office areas where PCs are used have half the level of lighting you would find in a standard office. The experts also suggest finding and eliminating the sources of glare, such as windows and light-colored walls near the PC.
One reason PC users are more sensitive to light is that their eyes are wide open more of the time. The articles cite studies indicating that people blink much less often when staring at a computer display. This also tends to dry out the eyes, which is why many eye professionals recommend avoiding low-humidity work environments.
One way to give your eyes a break is to look away from the computer to a point at least 20 feet away for at least 20 seconds. Repeat each hour. An alternative is to close your eyes at least once an hour for about 30 seconds. But then people might think you were praying. (I've worked in offices where a prayer was about all we had.)
Adjust the display's brightness and contrast
In a CNET TV video, Eric Franklin describes how to use the free DisplayMate software to . As Eric notes, the higher you set the monitor's brightness, the quicker your eyes will give out.
Increase the size of your text
The All About Vision site suggests a simple way to determine your ideal text size: find the smallest size font you can see on the monitor and multiply that size by three. Browsers offer various ways to adjust the type size of Web pages, such as by using the mouse scroll button. I described several in a post from last January.
Don't neglect the rest of your workstation
Back in 2009 I described several resources that help you . One great site that wasn't included in that post is Stanford University's "Keys to safe computer use," which covers everything from keyboard shortcuts to reduce mouse use, to techniques for determining the correct height of your seat. The site includes a downloadable ergonomics PDF you can print as a trifold brochure that describes stretches you can do while seated.
Take breaks--lots of breaks
Rest breaks benefit more than just our eyes. Unfortunately, the demands of our jobs give us few opportunities in a workday to bust out of the cube farm. Most states require that employers offer their workers regular breaks during their shifts, and many organizations actively encourage their employees to take their allotment of rest periods each workday.
The fact is, many of us regularly work through our breaks--usually voluntarily. Just keep in mind that doing without work breaks can be hazardous to your health, in many different ways.