Using your Eyes and your Computer

Using Your Eyes and Your Computer
To minimize discomfort when working at your computer
avoid looking at the monitor for long periods of time.
It’s 1:00 p.m.
and you’ve been working at your computer since 9:00 a.m. Your eyes feel irritated and fatigued
your vision is blurry
and you still have several hours of work ahead of you.

The symptoms you are experiencing are common among people who do considerable “near” work
including those who work with computers. The symptoms may be a result of the way that you use the equipment and furnishings at your workstation. But they may also be
at least partly
the result of a vision problem. Anytime you experience symptoms like eye strain
blurred vision
eye irritation
double vision
excessive tears or dry eyes
pain in the eyes
or excessive blinking and squinting
you should visit your eye care practitioner for a comprehensive eye examination.

After you have had a comprehensive eye examination
there are a number of things that you can do to arrange your workstation to eliminate or minimize discomfort.


Adjusting your chair

Many times
your chair can be adjusted to make your workstation much more efficient and comfortable. For instance:

  • Your feet should be flat on the floor with your knees bent close to or greater than 90 degrees – if your feet do not reach the floor get a footrest.
  • Your chair seat should support your legs without excessive pressure on the back of your thighs.
  • Your back should be snug against the seat to fit your spinal contour. Your thigh to trunk angle should be 90 degrees or greater.
  • The distance from the front of your chair to the hollow of your knee should be 2”-4”.
  • Your wrist and hands should extend nearly straight from the elbow to the home row of the keyboard.

Setting up your work surface

Consider the following suggestions to make sure the height of your work surface and the amount of leg room it provides are comfortable.

  • For most people the amount of leg room below the work surface should be about 25” high by 27” wide by 27” deep. Larger people will require more space.
  • A commonly preferred work surface height for computer use is about 26” as opposed to conventional 29” of most tables or desks.

Using your monitor and keyboard

The following suggestions will help you arrange your computer monitor and keyboard to allow you to work most productively and comfortably:

  • Locate your monitor 16” -30” from your eyes depending on the size of your monitor and your individual vision conditions. Many people find 20” – 26” most comfortable.
  • The top of the monitor should be slightly below a 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 20 degrees to 30 degrees below your eyes. This is 4” to 9” below your eyes at a distance of 24”.
  • Keep your monitor free of fingerprints and dust. Both can reduce clarity.
  • Place document holders close to your screen within the same viewing distance. Keep your keyboard and monitor in line.
  • Adjust your keyboard tilt angle so that your wrists are straight.

Computers and lighting

To improve visual efficiency when using your computer:

  • Adjust the brightness of the monitor to an intensity that is comfortable for your eyes; not too bright and not to dim. Eliminate bright light sources from your peripheral vision.
  • Next adjust the contrast between the characters on the monitor and the background so the letters are easily read. Repeat the brightness adjustment and then the contrast adjustment. If necessary write in bigger font.
  • Minimize the reflected glare on your monitor by using anti-glare screens or hood shields.
  • Position your monitor perpendicular to windows or other bright light sources to reduce glare.
  • Turn the monitor slightly so light doesn’t reflect into your eyes.

To minimize discomfort when working at your computer
avoid looking at the monitor for long periods of time. Occasionally rest your eyes for a few moments by closing them or looking into the distance. As you work
make an effort to blink more frequently than you normally do
which will keep your eyes from drying out and feeling irritated. Try your best to take rest breaks
too. Some experts recommend a brief break every 45 minutes or so; others suggest a 15-minute break from the computer every two hours.

Another possible cause of discomfort is uncorrected refractive errors. This can cause eye fatigue
so if your eyes tire easily or your vision blurs periodically
a check-up with your eye care practitioner may be in order. In addition
you may need “occupational” glasses designed for your viewing angle and exact distance from the screen. If you wear progressive lenses
the location of your glasses in relation to the screen is crucial (the reading portion of your bifocals must be in the exact position for reading material onscreen or else possible neck- or headaches will result.)