Smokers are four times as likely as nonsmokers to develop a form of eye disease called age-related macular degeneration that can lead to blindness, new research indicates.

Age-related macular degeneration, or AMD, causes the light-sensing cells in the retina to die off, causing vision loss. “The bottom line for people worried about age-related macular degeneration is that there is a modifiable risk factor that is very, very strong, and that’s smoking,” study co-author Dr. Peter Gehlbach, of Johns Hopkins University in Baltimore, told Reuters.

Nearly 30 percent of Americans over 75 have AMD, according to the National Eye Institute. There are two forms of AMD, wet and dry. The wet form is marked by leaky blood vessels in the retina, while the more common dry form progresses more slowly.

The study, published in the journal Ophthalmology, included 279 men and women with AMD and 143 adults without the disease. In addition to an increased risk of AMD, smokers were nearly five times as likely as nonsmokers to develop an eye disease called polypoidal choroidal vasculopathy, which also leads to bleeding in the retina.