Working World

More prevalent than carpal tunnel syndrome but less reported in the media, computer vision syndrome (CVS) detracts from personal comfort and work efficiency. Both the National Institute for Occupational Safety and Health and the American Optometric Association report that nearly 75 percent of all computer users in the U.S. workforce have experienced one or more computer-related eye symptoms that fall in the CVS category, and many more may not even know they are experiencing it until troublesome symptoms begin appearing. With computers becoming an occupational and recreational way of life, CVS prevention is critically important.

Unlike printed materials in which letters appear uniform and crisp to the eyes, viewing computer images is much more of a strain. Reading the screen is much like a digital camera or camcorder set to autofocus — the image will be blurry, then clear, then blurry again in an attempt to find the clearest resolution possible.

Onscreen characters are made up of many tiny squares known as pixels, each illuminated from the center and fading in brightness toward the edge. Since each onscreen text character and graphic is composed of roughly 72 pixels per square inch, the eye must constantly flex and focus in an attempt to construct clear and uniform images.

Over time this leads to tired eyes marked by blurred vision both onscreen and off, dry or burning sensations, light sensitivity, and neck and shoulder pain from the body trying to readjust itself to be able to focus more clearly.

Fortunately, there are a few workplace adjustments that can be made to help prevent and alleviate the discomfort of CVS-related symptoms. Whether symptoms are mild, severe or not yet surfaced, putting these five best practices into action will make computer exposure easier on your eyes for years to come.

1. Invest in a pair of computer glasses.
Many optometrists now choose to specialize in treating CVS symptoms in addition to their regular practice. Most eyeglasses and contact lenses are not effective in helping your eyes to resolve mid-range objects like those that appear on computer screens. Prescriptions are measured for clarity in close distance, like reading, or for viewing objects that are further away, such as glasses used while driving or watching television. Computer glasses prescriptions by contrast are measured at the computer working distance.

Even if you already wear contact lenses or corrective lenses, you may want to look into an additional pair of computer glasses that you can wear while working in front of the computer. It may seem strange at first to have a specialized pair of glasses for computer work only, but these glasses are very helpful in reducing troublesome CVS symptoms and preserving the eye's ability to focus onscreen.

Just like sunglasses are worn to protect eyes during time spent in the sun, computer glasses help protect your eyes from time spent looking into a computer screen.

2. Reduce screen glare.
Glare may not seem like a problem if you've never thought about it, but it plays a major part in CVS. Anything that makes the eyes work harder to focus and refocus on onscreen characters and graphics further contributes to the problem. While each work environment is different, the main sources of computer screen glare are windows, overhead fluorescent lights and desk lamps.

Try closing window shades, using a desk lamp that throws softer and more uniform light, and shutting off at least half of the overhead fluorescents (many office fluorescents have two light switches per rowed section). If those are not viable options in your workplace, consider installing an anti-glare filter or screen visor that fits over the monitor, being sure to adjust the brightness and contrast of your computer settings to best balance the brightness with your surroundings. The goal is not to eliminate light sources, but to balance them as much as possible with what appears on your screen.

3. Take frequent eye breaks, blink more frequently.
Every 15-20 minutes take a break to gaze at mid-range and distant objects in your surroundings. This will allow the eyes to focus on objects that are more uniform than onscreen pixels. You don't necessarily need to physically get up from your chair and walk around; simply look around.

Additionally, consciously blinking more often helps lubricate the eye since computer work typically reduces the blinking rate, thereby drying out the eyes. Using artificial tears during the workday can also be helpful at replenishing lost moisture in the eyes lost to dry and air-conditioned offices.

4. Print out documents and graphics.
You can reduce onscreen viewing time by printing documents and working from printed copies whenever possible. This can be especially helpful for occupations like proofreaders and editors, who spend most working hours reading large blocks of text and graphics.

5. Check your monitor ergonomics.
In addition to taking steps to reduce common musculoskeletal symptoms such as carpal tunnel syndrome and neck, shoulder and back pain, it is also a good idea to reposition your monitor to achieve the least stressful impact on your eyes. Like carpal tunnel, CVS can be thought of as a repetitive stress effect.

A good rule of thumb is to position the top portion of your monitor 20 to 28 inches from you, just below where your line of sight falls naturally when looking straight ahead. It is also slightly easier to focus on objects while looking downward than upward, and positioning your monitor above this line of sight causes the eyes to focus upward, causing tension in the neck and shoulders.     

SIDEBAR

Common Computer Vision Syndrome Symptoms 

•    Headaches
•    Intermittent blurry or fuzzy vision, both onscreen and off
•    Dry, burning eyes
•    Bloodshot eyes
•    Slight double vision
•    Light sensitivity
•    Neck and shoulder pain

Chrissy Coleman is a freelance journalist and copywriter covering dating, relationship, family and work issues. She holds a degree in journalism and lives in Los Angeles.

1 COMMENTS

• Catherine Rhodes

  There's a great deal of difference in the resolution between a printed page and a computer screen. The page is 300 dots per inch (dpi) while the screen is only 72. This makes it far more difficult to focus for long periods of time without eye strain. I noticed that the Kindle, the online book upload system by Amazon, is 180 dpi, so it will be interesting whether that is high enough resolution to allow people to read comfortably for long periods of time.

  Dec 31, 2008