Working in front of a monitor for more than seven hours per day may lead to symptoms similar to those of dry eye disease, a new study has warned.

The tear fluid that protects and lubricates the eye contains a protein called MUC5AC that is secreted by specialised cells in the upper eyelid.

Researchers have found the levels of MUC5AC in the tears of those who stare for long periods at computer screens were almost as low as in people with dry eye disease, 'Utah People's Post' reported.

People staring at screens also tend to open their eyelids wider as compared to 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.

"Office workers who are worried about dry eye can make some simple changes to decrease the risk of disease. The exposed ocular surface area can be decreased by placing the terminal at a lower height, with the screen tilted upward," Dr Yuichi Uchino, an ophthalmologist at the School of Medicine at Keio University in Tokyo said.

Researchers sampled tears from the eyes of 96 Japanese office workers, roughly two-thirds of which were men. They then measured the concentration of MUC5AC proportional to the total amount of protein in the tears.

The amount of MUC5AC in the tears of workers who looked at screens for more than seven hours per day was, on average, 38.5 per cent lower than the amount in the workers who spent fewer than five hours a day looking at screens.

Among the subjects, 14 per cent were diagnosed with dry eye disease and had 57 per cent less MUC5AC in their tears compared to those without dry eye disease, the report said.

The research was published in the journal JAMA Ophthalmology.