It's very similar to what happens to drivers at night, when they concentrate on the road, forget to blink and experience eyestrain. The cornea isn't lubricated, and then they feel all sorts of sensations as the eye tells them they have a problem. Weiss recommends that computer users close their eyes for breaks and blink frequently. Those who wear contact lenses, in particular, should use supplemental lubricants or artificial tears. Professor Bob Beaton, a researcher at Virginia Tech in Blacksburg who has worked on glare filters for 15 years, said properly designed anti-reflection filters improved contrast, making the screen easier to see.
People often set brightness inappropriately, unaware that brightness and contrast work together.
A filter helps when circuitry on the computer can't make the screen bright enough for the contrast users want. Beaton said filters had little, if any, effect on the resolution of the display. They can attenuate or minimize reflections of a bright office or a bright shirt. Make sure light is not cast directly on the screen from windows, then adjust the monitor properly so that it is bright but sharp. The larger the screen, the better the resolution, given decent software.