Office workers who spend long hours looking at computer screens have changes in their tear fluid similar to people with the disease known as dry eye, according to a study from Japan.

The protein MUC5AC, secreted by cells in the upper eyelid, makes up part of the normally occurring mucus layer, or tear film, that keeps the eye moist. But study participants with the most screen time had MUC5AC levels nearing those of people with diagnosed dry eye.

At computers, our blinking times decreased compared to reading a book at the table. People staring at screens tend to open their eyelids wider than while doing other tasks, and the extra exposed surface area in addition to infrequent blinking can accelerate tear evaporation and is associated with dry eye disease, Dr. Yuichi Uchino, an ophthalmologist at the School of Medicine at Keio University in Tokyo said.

Researchers tested the tears from both eyes of 96 Japanese office workers, about two-thirds of them men, and measured how much of the total protein content of the tears was MUC5AC.
Seven percent of men and 14 percent of women were diagnosed with ‘dry eye disease,’ they reported symptoms of eye problems like irritation, burning or blurred vision and had poor quality or quantity of tear film.

According to previous studies people with dry eyes at work tend to be less productive and are more likely to be depressed.

The exposed ocular surface area can be decreased by placing the terminal at a lower height, with the screen tilted upward.
Workers suffering from ocular fatigue and dry eye symptoms should blink more frequently in an intended manner during screen use and should use artificial tears.
Doctors recommend using a humidifier at the office and avoiding being in the direct path of the wind from an air conditioner.

For more information
JAMA Ophthalmology
Alteration of Tear Mucin 5AC in Office Workers Using Visual Display Terminals

MDN