Many reported cases of serious eye damage result from misusing contact lenses, including sleeping in them or wearing them beyond their recommended use, a report released Thursday by the Centers for Disease Control and Prevention (CDC) suggests. Between 2005 and 2015, the Food and Drug Administration (FDA) received reports of 1,075 contact lens-related corneal infections that involved ulcers or keratitis, which is inflammation of the cornea, according to a CDC news release. About 20 percent of these reports involved serious eye damage, but about a quarter of those cases could have been avoided with proper contact lens use.

About 41 million Americans wear contact lenses, and in 2014, more than 99 percent of patients surveyed reported having at least one behavior that puts them at risk for a contact lens-related eye infection, the CDC noted. Keratitis sends an estimated 1 million patients to clinics and ERs annually, and in 2010 those visits accounted for $175 million in direct health care expenditures, according to the report. Researchers defined serious eye damage as having a central corneal scar, a decrease in vision, or the need of a corneal transplant. The most common contact lens abuse was wearing them for an extended period when not approved for that use (about 11 percent)— which often led the patients to discontinue using them— followed by wearing contact lenses beyond their prescription (8 percent), and occasional overnight wear or napping in lenses (7 percent). Other patients abused contact lenses by using expired products, storing lenses in water, or wearing lenses while swimming.