Using Your Eyes and Your Computer
It’s 11:30 in the morning. You’ve been working at your computer since 9:00 AM. Your eyes feel irritated and fatigued, your vision is blurry and you still have several hours of work ahead of you.
The symptoms that you are experiencing are common among people who do considerable near work including those who work with computers. They may be a result of the way that you use the equipment and furnishings in your workstation. But they may also be, at least partly, the result of a vision problem. Anytime you experience symptoms like headaches, eye strain, blurred vision, eye irritation, double vision, excessive tears or dry eyes, pain in the eyes or excessive blinking or squinting, you should visit your doctor of optometry for a comprehensive eye examination. And, when you do, be sure to tell the doctor about the computer work that you do.
After you have had a comprehensive eye examination, there are a number of things that you can do to arrange and use the elements of your workstation to eliminate or minimize discomfort.
Adjusting your chair
Many times, your chair can be adjusted to make your work station much more efficient and comfortable. For instance:
- Your feet should be flat on the floor (or on a slightly angled foot rest) with your knees bent close to or greater than 90 degrees.
- 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 hand 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 your 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 10 degrees to 20 degrees below your eyes. This is 4″-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 to your eyes; not too bright and not too 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.
- Minimize reflected glare on your monitor by using window treatments, dimmer switches on lights and anti-glare screens. Look for anti-glare screens that have recieved the American Optometric Association Seal of Acceptance.
- Position your monitor perpendicular to windows or other bright light sources to reduce glare.
Human eyes were made for most efficient operation at a distance, but if you use the suggestions made here and those made by your doctor of optometry you will be able to use your computer more comfortably and productively.