Ageing is a major risk factor for glaucoma and cataracts, two conditions that can cause sight loss. Glaucoma damages the optic nerve, which carries information from the eye to the brain, and can permanently reduce vision. Cataracts develop when the eye’s lens becomes cloudy, making vision blurred and potentially causing blindness.
A review of 41 studies involving millions of people across East Asia and the UK suggests that air pollution is also linked to these diseases. The clearest links involved PM2.5: tiny particles in the air measuring no more than 2.5 micrometres across. People exposed to higher levels of these particles had a greater risk of glaucoma and cataracts. Most studies estimated long-term exposure using pollution levels near people’s homes and in their communities.
These findings show a connection, not proof that pollution causes either disease. Researchers suggest that fine particles may enter the body and trigger processes that damage eye cells. However, exactly how pollution might contribute to these conditions remains unclear.
