computer vision

Computer Vision

Nearly one-half of American adults use a computer. Studies show that as high as 90 percent of people who work with computers more than three hours a day suffer from some type of eye trouble commonly known as Computer Vision Syndrome (CVS). Because Computer Vision Syndrome can lead to muscular discomfort in your neck and back, we recommend the following tips to minimize your risk.

Viewing Distance Between you and your Monitor

The body assumes whatever position necessary to enable the eyes to see comfortably. A poorly located monitor causes awkward body positions. It is important that your monitor be located so that it is comfortable for both your eyes and body.

  • A viewing distance of 20-28 inches is most common. If your viewing distance is outside this range, it may indicate a visual problem or it may contribute to posture-related symptoms.

Adjusting Monitor Height and Location

The eyes work best at a slightly downward gaze. Therefore, the center of the monitor should be 4-9 inches below your straight ahead vision. The monitor should also be positioned directly in front of you so that you don’t have to look sideways or twist your body or neck to see it.

If the screen is too low (more than 9” below your eyes), consider the following:

  • Raise the computer screen. (Spacers can be purchased or old phone books will work).
  • Lower the chair, but don’t allow the seat to become lower than the bottom of your kneecap.

If your screen is too high (higher than 4” below the eyes), consider the following:

  • Lower the monitor (take it off the hard drive component of your computer).
  • Raise the chair, taking care to keep your feet on the ground.

Lighting

Bright lights or other brightly colored objects in one’s peripheral vision are uncomfortable for the eyes. Methods of eliminating bothersome lights from your field of view include:

  • Turn off the light that is bothering you.
  • Close the blinds or drapes.
  • Rotate your workstation so that the bright lights are not in your field of view.
  • Consider wearing a visor or using a shield to block bright lights.

Reflections from your Monitor

Reflections from your monitor reduce contrast and make it difficult to see the screen. The following steps will improve screen visibility:

  • If possible, remove the offending source of light. You may be able to turn off the fluorescent light that is causing the problem or close the drapes or blinds on a window.
  • Hoods for your monitor can be used to reduce reflections.
  • Look for anti-reflection screens that have been approved by the American Optometric Association.

Dry Eyes

Studies have shown that we blink approximately 50% less often when we are working on the computer. This can lead to dry, burning irritated eyes. If you experience any of these symptoms, we recommend that you have a bottle of lubricating drops at your desk and use them every 2-3 hours while on the computer.

Focusing

If you had to hold a 20 pound weight for 20 minutes, chances are your muscles would start to fatigue and cramp. This principle also applies to your eye focusing muscles. A common symptom of CVS is poor ability to change focus from near to far, or difficulty seeing distant objects at the end of the day. We recommend that for every 20 minutes you spend on the computer screen, you take a 20 second break and focus on something 20 feet away; the “20/20/20” rule. This allows your eye focusing muscles the opportunity to relax and maintain flexibility.

Your doctor may also recommend a pair of computer glasses that you keep at your computer. Just like we have multiple types of shoes for running, walking, or dress-wear, so too may you need an occupational pair of computer glasses. Computer glasses with anti-reflective lenses help reduce eye-strain from computer glare and provide the most accurate vision for computer distance.