Health Risks of Computer Screens

By John Lister

Sensible use of a monitor will minimize health risks.
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The potential risks from using computer monitors fall into four categories: eye strain; repetitive strain injury to the neck and other body parts; radiation; and chemical emissions. Most medical research that has been published suggests that the risks are relatively low and that with sensible use most people should not experience any significant medical problems.

Eye Strain

The Mayo Clinic reports that using computer screens for an extended period can cause eye strain, also known as computer vision syndrome. Symptoms include sore or tired eyes, difficulty focusing, and blurred or double vision. Ways to minimize the problem include using natural lighting wherever possible, aiming light away from the screen to reduce glare, and making sure the screen is around 20 to 30 inches from your eyes to avoid squinting or straining. You can also take occasional breaks to exercise your eyes. One trick is to use the 20-20-20 rule by which every 20 minutes you stop working and focus your attention on an item 20 feet away for 20 seconds. If you follow all these steps and still have eye strain from computer use, it could be a sign of underlying eye conditions, so seek medical advice.


Repetitive Strain Injury can come from two main behaviors, working separately or in conjunction: using a monitor for too long without a break and using a monitor incorrectly. The latter can include having the screen too close or too far away, meaning you move your head back or forth into an unnatural and uncomfortable position. The ideal position is at arm's length. It can also be from having the screen too far to one side, or too high or low. The ideal position is straight ahead and either at or slightly below eye level, such that you can see the entire monitor just by moving your eyes rather than your head. Computer use can still lead to RSI if your keyboard or mouse are in awkward positions.


Computer monitors do emit low levels of radiation, but the radiation is not at harmful levels, even to pregnant women. No credible medical studies have shown clear evidence of any danger. U.S. law requires that monitor manufacturers test radiation and keep monitor emissions at safe levels.


A 2000 study by the University of Stockholm found that cathode-ray monitors may emit "significant" levels of triphenyl phosphate, used as a flame retardant. This could contribute to nasal congestion, headaches and skin allergies. The researchers suggested that leaving the monitor turned on but kept away from users for 10 days after purchase could reduce the exposure by around two-thirds. These risks may be heavily reduced in modern flat screen monitors, simply because they have less surface area requiring flame retardants.