Doctor and senior woman wearing facemasks during coronavirus and flu outbreak. Virus protection. COVID-2019..

Researchers have found that more than 28 million Americans over age 40 have eye ailments that put them at risk for vision loss and blindness, as published in Monday’s Archives of Ophthalmology. The number is expected to soar as the population ages.

Cataracts are the leading cause of blindness worldwide and the biggest cause of poor vision in the United States, affecting an estimated 20.5 million American adults, according the study. That number is expected to reach 30.1 million in the next 20 years.

Macular degeneration, glaucoma and diabetic retinopathy are also major causes of blindness and vision loss and are strongly linked with aging.

The data are crucial for showing where research dollars need to be spent, according to an accompanying editorial. Johns Hopkins University researcher James Tielsch wrote there may be a “tidal wave of chronic ocular disease over the next few decades.” Similarly, the study shows there will be substantial increases in healthcare costs that need to be addressed, experts say.