A new American study found that regular aspirin use is associated with an increased risk of developing a rare eye disease.

A study published in the Journal of the American Medical Association found that people who regularly took aspirin doubled their chances of contracting neovascular macular degeneration of the retina, the most severe form of macular degeneration. However, the increase in risk was very small – an increase was seen in about 1 in 200 older adults.

Although the risk was low, the results can still be significant because 1 in 5 adults take aspirin on a regular basis to prevent diseases such as heart disease and certain types of cancer.

Retinal dystrophy is a chronic eye disease that ultimately leads to deterioration of the macula, the center of the retina. As a result, central vision is gradually blurring, and it becomes more difficult for patients to distinguish between fine details.

The researchers used data from a long-term eye study that has followed thousands of patients for over 30 years. People in the study were classified as using aspirin if they took at least 2 aspirin tablets per week for more than 3 months. The people who took aspirin for the longest ultimately had the highest risk of developing the disease.

Scientists emphasize that the results should not discourage someone from continuing to take aspirin – especially if it was prescribed by a doctor. “It’s better to have blurry vision than to die of a heart attack,” they say.