Monitors should be at a comfortable viewing distance, which is approximately an arm's length. Users with bifocal glasses should tilt their monitors slightly backwards. Lighting Always use a good amount of ambient light, even though a computer screen is self-illuminating. There should never be a large contrast between the screen and the area surrounding it. In addition, there should be no glare falling on the screen.
Glare can cause discomfort, eyestrain and headaches.
Avoid glossy work surfaces and furnishings which can contribute to glare. Breaks are Important The risk of problems associated with computer use depends more on the amount of time that one spends keyboarding without taking a break. Looking at a computer screen for extended periods of time causes some changes in how the eyes work, causing less blinking and more exposure to air and dust. Every 15 minutes you should briefly look away from your screen and focus for a minute or two on a more distance object. This allows the muscles inside your eye to relax.