People who regularly take aspirin for many years, such as those with heart problems, are more likely to develop a form of blindness, researchers say.
A study on 2,389 people, in the journal JAMA Internal Medicine, showed aspirin takers had twice the risk
of "wet" age-related macular degeneration.
The disease damages the 'sweet spot' in the retina, obscuring details in the centre of a patient's field of vision.
One in 10 people in the study, conducted at the University of Sydney, were taking aspirin at least once a week. On average the participants were in their mid-60s.
Eye tests were performed after five, 10 and 15 years.
By the end of the study, the researchers showed that 9.3% of patients taking aspirin developed wet age-related macular degeneration (AMD) compared with 3.7% of patients who did not take aspirin.
Their report said: "The increased risk of [wet] AMD was detected only after 10 or 15 years, suggesting that cumulative dosing is important."