Computer Eye Strain
Steps for Relief
With so many of us using computers at work, computer eye strain has become a major job-related complaint. Studies show that eye strain and other bothersome visual symptoms occur in 50 to 90 percent of computer workers.
These problems can range from physical fatigue, decreased productivity and increased numbers of work errors, to minor annoyances like eye twitching and red eyes.
Here are easy steps you can take to reduce your risk of computer eye strain and other common symptoms of computer vision syndrome (CVS):
1. Get a comprehensive eye exam
Having a routine comprehensive eye exam is the most important thing you can do to prevent or treat computer vision problems.
According to the National Institute of Occupational Safety and Health (NIOSH), computer users should have an eye exam before they start working on a computer and once a year thereafter.
During your exam, be sure to tell your eye doctor how often you use a computer at work and at home. Measure how far your eyes are from your screen when you sit at your computer, and bring this measurement to your exam so your eye doctor can test your eyes at that specific working distance.
2. Use proper lighting
Eye strain often is 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 as bright as that typically 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 computer monitor or screen so windows are to the side, instead of in front or behind it.
Many computer users find their eyes feel better if they can avoid working under overhead fluorescent lights. If possible, turn off the overhead fluorescent lights in your office and use floor lamps that provide indirect incandescent or halogen lighting instead.
Sometimes switching to 'full spectrum' fluorescent lighting that more closely approximates the light spectrum emitted by sunlight can be more comforting for computer work than regular fluorescent tubes. But even full spectrum lighting can cause discomfort if it's too bright. Try reducing the number of fluorescent tubes installed above your computer workspace if you are bothered by overhead lighting.
3. Minimize glare
Glare on walls and finished surfaces, as well as reflections on your computer screen also can cause computer eye strain. Consider installing an anti-glare screen on your monitor and, if possible, paint bright white walls a darker color with a matte finish.
Again, cover the windows. When outside light cannot be reduced, consider using a computer hood.
If you wear glasses, purchase lenses with anti-reflective (AR) coating. AR coating reduces glare by minimizing the amount of light reflecting off the front and back surfaces of your eyeglass lenses.
If your older monitor is causing computer eye strain, replace it with a flat-panel LCD screen that is easier on the eyes.
4. Upgrade your display
If you have not already done so, replace your old tube-style monitor (called a cathode ray tube or CRT) with a flat-panel liquid crystal display (LCD), like those on laptop computers.
LCD screens are easier on the eyes and usually have an anti-reflective surface. Old-fashioned CRT screens can cause a noticeable 'flicker' of images, which is a major cause of computer eyestrain. Even if this flicker is imperceptible, it still can contribute to eye strain and fatigue during computer work.
Complications due to flicker are even more likely if the refresh rate of the monitor is less than 75 hertz (Hz). If you must use a CRT at work, adjust the display settings to the highest possible refresh rate.
When choosing a new flat panel display, select a screen with the highest resolution possible. Resolution is related to the 'dot pitch' of the display. Generally, displays with a lower dot pitch have sharper images. Choose a display with a dot pitch of .28 mm or smaller.
Flicker is not an issue with LCD screens, since the brightness of pixels on the display are controlled by a 'backlight' that typically operates at 200 Hz.
If you see a lower refresh rate (e.g. 60 Hz) noted on an LCD screen, don't worry - this refers to how often a new image is received from the video card, not how often the pixel brightness of the display is updated, and this function typically is not associated with eye strain.
Finally, choose a relatively large display. For a desktop computer, select a display that has a diagonal screen size of at least 19 inches.
5. Adjust your computer display settings
Adjusting the display settings of your computer can help reduce eye strain and fatigue. Generally, these adjustments are beneficial:
Brightness.: Adjust the brightness of the display so it's approximately the same as the brightness of your surrounding workstation. As a test, look 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.
Text size and contrast.: Adjust the text size and contrast for comfort, especially when reading or composing long documents. Usually, black print on a white background is the best combination for comfort.