Woman nearly loses sight in one eye after wearing contacts in shower and pool

You may want to think twice about showering or swimming with your contact lenses in.

A 41-year-old woman in England nearly lost her vision in one eye from an infection she got after swimming and showering while wearing contact lenses. Her case is described in a brief report published Wednesday in the New England Journal of Medicine.

Many contact lens wearers are unaware of the risk of this infection, called Acanthamoeba keratitis. Indeed, it’s exceedingly rare. In the U.S., the Centers for Disease Control and Prevention estimates there are one to two cases per million contact lens wearers.

“I’ve been practicing optometry for 19 years and I’ve seen two cases,” said Dr. Shilpa Register, an optometrist and clinical assistant professor with the University of Alabama at Birmingham department of ophthalmology and visual sciences, who was not involved with the woman’s case. “When it happens it’s severe, and it can cause blindness pretty quickly if it’s not treated immediately.”

The eye infection is caused by a microscopic, free-living amoeba called Acanthamoeba that’s commonly found in water and soil. Any kind of water exposure while wearing soft contacts puts a person at risk.