Computer Vision Syndrome, or CVS, refers to the vision problems associated with the use of a computer monitor or video display terminal (VDT). The most common symptoms include dry, tired and burning eyes, difficulty focusing, eye strain, double vision, headaches, blurred vision, as well as, neck and shoulder pain.
The American Optometric Association recently conducted a telephone survey of 1,000 American consumers’ use of computers and hand held devices. The survey found:
- Forty-two percent of Americans spend three or more hours each day in front of a computer or handheld device.
- Forty-one percent have complained of eye strain and 45 percent suffer from neck or back pain from prolonged computer or hand held device use.
- Special computer glasses and other computer products are available to help reduce glare and discomfort, but only 11 percent of Americans currently use these devices.
Some suggestions to alleviate the symptoms include:
Limit the amount of time you continuously use the computer. Practicing the 20/20 rule (look away from the computer every 20 minutes for 20 seconds) will minimize the development of eye-focusing problems and eye irritation caused by infrequent blinking.
Check the height and arrangement of the computer. More comfortable computer viewing can be achieved when the eyes are looking downward. Optimally, the computer screen should be 15 to 20 degrees below eye level (about 4 or 5 inches) as measured from the center of the screen and 20 to 28 inches from the eyes.
Check for glare on the computer screen. Windows or other light sources should not be directly visible when sitting in front of the monitor. When this occurs, turn the desk or computer to prevent glare on the screen.
Reduce the amount of lighting in the room to match the computer screen. A desk lamp can be substituted for a bright overhead light or a dimmer switch can be installed to give flexible control of room lighting. Turn three-way bulbs to the lowest setting.
Keep Blinking. To minimize the chances of developing dry eye when using a computer, make an effort to blink frequently. Blinking keeps the front surface of the eye moist. Artificial tears may also be used throughout the day to increase the moisture of the eyes.
Upgrade to a Large Flat Panel Display. The new LCD flat panel displays are much better than the old CRT displays and are easier on the eyes. They have an anti-reflective coating and do not have issues with flicker like their predecessors. If you must use a CRT, be sure to set the refresh rate to highest possible setting. When selecting an LCD monitor be sure to select one with the best possible resolution. Resolution is related to the “dot pitch” of the display. You will get a sharper image with a lower dot pitch display. Try to choose a display with a dot pitch of .28 mm or lower.
Consider Computer Eyewear. Computer users normally sit 20 to 26 inches from their computer. This is considered to be an intermediate zone of vision — closer than driving ("distance") vision, but farther away than reading ("near") vision. For this reason distance glasses and normal reading glasses may not work well at this intermediate distance. Computer users attempting to use their normal bifocal or progressive lenses may end up with neck and shoulder pain when they attempt to view their computer monitor through the lower portion of their lenses by lifting their chins up. Better options include single vision reading glasses set for the individual user’s computer distance, computer progressives, or a bifocal with the top portion of the lens set for the computer distance and the bottom for close work.
Computer Vision Syndrome affects not only millions of office workers, but also students and the retired who use computers on a daily basis. Only when the eyes are able to focus clearly at the appropriate distance, will computer users begin to feel relief from eyestrain. This can be achieved through the use of eyewear designed for use specifically at the computer. Further relief can be achieved by minimizing glare from overhead lights and windows. LCD monitors with their antireflective coatings and high resolution can provide even more relief. If you are suffer from symptoms of CVS, make an appointment with your eye doctor. He or she can help map out a plan to help you find relief.
Links:
http://www.allaboutvision.com/cvs/irritated.htm
http://www.allaboutvision.com/cvs/faqs.htm
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