It is helpful to use a copyholder. A good viewing distance is 22 to 26 inches. Some people may need special glasses for focusing at the intermediate distance that is neither as long a distance as prescriptions for nearsightedness usually encompass, nor a typical reading distance. This is particularly true if you wear reading glasses or bifocals. Tell your eye-care professional if you use a computer for long periods, and discuss any eye discomfort you have.
Dust can make the eyes tear, feel gritty, or turn red.
Proper humidity and ventilation are important. There are cleaners available to remove dust from the screen. Alternating only 60 times a second, the effects of these fields are at the center of a scientific controversy. Some studies of humans exposed to ELF radiation have suggested an association between this exposure and certain types of cancer. But the evidence is not clear.