While this statement may not be altogether true, extended computer or television use may indeed take a toll on the eyes. Eyestrain can be caused by any work involving heavy eye concentration on one particular point, such as reading, computer work and watching television. However, the strain is not a result of sitting too close or the effects of radiation from the screen. Bradley Bowman, MD, tells WebMD that eyestrain is a result of focusing too hard. Bowman is an ophthalmologist and cornea specialist who also serves as medical director at HealthSouth Surgery Center of Dallas.
Conditions caused by focusing too hard include presbiopia and asthenopia.
Bowman explains that presbiopia and asthenopia are most common among middle-aged people and may cause eyestrain headaches. However, Bowman says that the more common scenario, at least in the workplace, is dry eyes. In normal conversation, a person blinks an average of 16 times per minute, but only three to four times per minute while focusing on a computer screen, Bowman says. This staring phenomenon causes tear film instability, resulting in dry eyes. Unless corrective steps are taken, dry eyes can cause blurred vision, headaches, gritty eye sensation, eye fatigue, decreased visual efficiency, more frequent errors and reduced overall efficiency.