Eye specialists of the premier medical institute call it a serious matter. They have approached the Union health ministry seeking funds to study the scale of the problem and find remedial measures."We have just completed an action plan involving screening of people living in different parts the city . Focus will be on areas where there is higher level of pollution, such as major traffic intersections, to assess the extent of the damage to the population," Dr J S Titiyal, professor and head of cornea, cataract and refractive surgery service at AIIMS, told TOI.

While the effects of pollution on the respiratory and circulatory system are well documented, experts say less attention has been paid to the damage caused to the outer layer of the eye, which is directly exposed to pollutants. Small particulate matters n affect the eyes in two wa can affect the eyes in two ways: firstly, they can cause dryness of the eyes, leading to irritation and redness. Secondly, they can cause watering of the eyes. Usually , these symptoms are controlled with application of artificial tears and topical steroids.

However, doctors say constant exposure to high level of pollutants impairs the healing process and the problem turns chronic in nearly 20% to 30% of patients. "It can also lead to poorer vision," said an ophthalmologist.

In 2003, AIIMS published a study comparing two groups of healthy volunteers living in Delhi and found greater instability of the tear film of the eye. According to the study , climatic conditions had a significant effect on outer surface of the eye. Researchers found those travelling through polluted areas had faced high levels of ocular surface abnormalities.

"If these abnormalities are found in the general population, then it is a cause for concern. Apart from implementing long-term steps to decrease the level of air pollution, short-term measures such as using protective goggles while travelling through polluted areas can be taken to decrease ocular contact with air-borne toxins," said an expert.

Titiyal said they conducted a questionnaire-based survey of 5,000 people who visited the hospital in the 20132014 period to assess the prevalence of eye problems. It was found that 10-15% of the people suffered from chronic irritation and dry eyes--conditions that are directly related to constant exposure to a high-level of pollutants.

"Such patients require medications such as artificial tears, anti-allergic medicines and, in some cases, steroids.But these can cause severe side-effects, including loss of vision, on long-term use," he said. Titiyal advised that people should wash their eyes after visiting heavily polluted areas.