Computer Work and Computer Vision Syndrome

I´ll bet you are doing what I am doing right at this very moment – sitting in front of the computer. Just like what millions of other people all over the world are doing right now. Whether you are doing it for business or for fun, sitting in front of the computer for prolonged periods of time can have some health consequences that need to be taken seriously. And one of the consequences is the effect on our vision.

As part of the Save Your Vision Month campaign this month, the American Optometric Association (AOA) gives us information about the computer vision syndrome (CVS).

The AOA defines CVS as “the complex of eye and vision problems related to near work that are experienced during or related to computer use.”

Here´s what happens when we work in front of a computer screen:

• We look straight ahead for long stretches.
• We blink less often.
• We usually work indoors, in an environment of low air humidity – such as in an office or at home.

All these can contribute the CVS.

In addition, we also use specific vision skills that place extra demands on our already overworked visual system, namely:

• Ocular motility – the ability of the eyes to move in various positions.
• Accommodation – the ability of the eyes to focus clearly at various distances.
• Vergence – The ability to move the eyes in (convergence) or out (divergence).

The computer screen itself presents some physical barriers that affect our vision, namely:

• Resolution
• Contrast
• Glare and reflections
• Image refresh rates and flicker
• Working distances and angles

Here are some tips from the AOA for a healthy, comfortable vision at the computer:

1. Have a regular comprehensive eye exam to ensure your eyes are healthy and that you have the correct eyeglass or contact lens prescription (if necessary). Be certain to tell your optometrist about the computer work you do.
2. Wear glasses that are specifically designed to function comfortably at the computer. The lenses you wear for day-to-day activities may not be the best for working at the computer. 
3. Practice the following eye care tips:

• Rest the eyes
• Blink forcefully
• Use a humidifier
• Instill artificial tear

4. Set up your work station for comfortable and effective computer use, as recommended below.

o Feet should be flat on the floor (or on a slightly angled foot rest) with knees bent close to or greater than 90 degrees.

o Chair seat should support the legs without excessive pressure on the back of the thighs.

o The back should be snug against the seat to fit your spinal contour. Thigh-to-trunk angle should be 90 degrees or greater.

o Wrists and hands should extend nearly straight from the elbow to the home row of the keyboard.

o A commonly preferred work surface height for keyboard use is about 26″ as opposed to the conventional 29″ of most tables or desks.

o Place the monitor 20″-26″ from your eyes, depending on the size of the monitor and individual vision conditions.

o The monitor and keyboard should be straight ahead.

o The top of the monitor should be slightly below horizontal eye level. Tilt the top of the monitor away from you at a 10 degree to 20 degree angle. The center of the monitor should be 10 degrees to 20 degrees below your eyes. This is 4-9 below your eyes at a distance of 24″

o Keep the monitor free of fingerprints and dust. Both can reduce clarity.

o Place document holders close to the screen within the same viewing distance. Keep the keyboard and monitor in line.

o Adjust the keyboard tilt angle so that wrists are straight.