That's for people who drink at least three cups a day.
The study found specifically caffeinated coffee appears to be associated with a type of glaucoma which is characterized by tiny fibers peeling from the eye's lens that can cause a pressure build-up.
The risks for glaucoma was even higher in people with a family history.
This is said to be the first study to link coffee consumption with this type of glaucoma risk, so scientists are saying further research is needed.
The report appears in the Journal of Investigative Ophthalmology and Visual Science.