How Computer Use Affects Your Vision
Many of us spend hours in front of a computer screen every day, and that can take a toll on your vision. Generally speaking, viewing objects farther away from us is easier on our eyes; conversely, the muscles in our eyes must work harder to view things at close range. Staring at a computer screen for long periods of time, therefore, can cause you to strain the muscles in your eyes and may result in headaches, blurred vision and eye fatigue.
There are changes you can make that may help relieve many computer-related vision problems, such as improving lighting in the work area, altering the workstation height, taking intermittent breaks, or obtaining prescription glasses for computer use.
Ambient Lighting and Screen Placement
- You may need to remove or dim overhead lights, and use desk lamps with shades for other deskwork.
- Natural light from windows should be controlled with blinds or drapes.
- Reduce reflected glare on your computer screen by placing it so windows and other bright light sources are not directly behind or in front.
- If you cannot solve glare problems by rearranging the furniture, try hoods that extend above the screen and glare shields that cover the screen. However these devices may interfere with the screen’s character resolution (the lightness or darkness of the type).
- Tilting the screen also may reduce glare. Glare-reducing computer screen overlays are also available
- Adjust the contrast (the lightness or darkness of the screen) to a comfortable level using the buttons on the terminal.
- Position the monitor 24-28 “ from your eyes with the top of the screen at eye level
- The center of the screen should be about 20 degrees below eye level
- Place reference materials as close to the monitor as possible. Copy holders are helpful in holding the material in place. By arranging the copy next to the screen, you reduce the need for excessive eye and head movements.
- Your monitor height should be adjustable.
- Reference material placed next to screen.
- Your wrists should be in a straight or “neutral” position.
- Your upper arm and forearm should create a 90-degree angle.
- Your chair height should be adjustable with good lower back support.
- Elbow, hip, and knee joints should be as close to 90 degrees as possible.
- Feet should be flat on the floor or on a footrest.
- Take regular breaks from your computer, such as 2-3 minutes each half-hour and 10-15 minutes every 2 hours.
- Regularly focus on distant objects. Look out a window or at an object at least 20 feet away to relax the eyes. Maintaining a close focus on the computer monitor can create a focusing spasm.
- Do simple stretching exercises to relax the whole body.
Extended demand on the eyes often causes visual problems. Even small amounts of the following uncorrected conditions may contribute to discomfort when using a computer:
- Nearsightedness: when eyes see close objects more clearly than distant objects)
- Astigmatism: when eyes see blurred or imperfect images)
- Anisometropia: when eyeglass prescriptions are different for each eye.
- Farsightedness: eyes see distant objects more clearly than close objects.
- Inefficient teaming of the two eyes: the two eyes don’t coordinate well together.
Consider scheduling an eye exam with your eye doctor to determine if you need computer glasses. These glasses are designed for the specific distance between the eyes and the screen and differ from your driving and reading glasses. Your eye doctor and optician can customize your lens choices to suit your individual environment:
- Tinted lenses can be helpful if your office uses fluorescent lighting.
- Single Vision lenses can maximize dedicated glasses area for computer viewing
- Bifocals for computer use are different from those used for driving and general near tasks. With this specialized bifocal prescription, the top segment of the spectacle is focused for the computer viewing distance, eliminating the wearer’s need to tilt the head up in order to focus on the computer screen. The bottom segment is focused for closer writing or reading distances.