Why You Should Never Shower With Your Contact Lenses In

Contact lenses offer a level of convenience for those with less-than-perfect vision that glasses can hardly compete with, but that doesn’t mean the daily struggle of taking them in and out of your eyes doesn’t wear on you. If you get a little lazy and decide it’s fine to leave them in your eyes during showers or pool parties, think again.

According to Popular Science, a 41-year-old woman in the UK lost sight in her left eye as a result of frequently showering and swimming without removing her contacts. The culprit was Acanthamoeba polyphaga, a protozoa that crawled into her eye and caused a cornea infection called Acanthamoeba keratitis. After two months of pain, blurry vision, and light sensitivity, the woman sought medical attention at the Manchester Royal Eye Hospital, where doctors discovered a ring shape in her left eye and a hazy layer covering her cornea. Upon testing her vision, they found that her left eye was now 20/200, which counts as legally blind in the United States.

Leela Raju, an ophthalmologist and cornea specialist at New York University, told Popular Science that the single-celled organisms “can be anywhere,” including pools, hot tubs, showers, dirty saline solution containers, and even tap water. Lens-wearers make up around 85 percent of those who get infected, and experts think it may be because the amoeba can latch onto a contact lens more easily than a bare eye.

Though Popular Science reports that Acanthamoeba keratitis only affects one or two people out of every million contact wearers each year, that’s no reason not to be careful. If you do catch it, you’ll likely need a cornea transplant, and even that won’t necessarily restore your eyesight to its previous state—after her transplant, the UK woman’s left eye now has 20/80 vision.

“It’s just a long road, for something that’s totally preventable,” Raju says. In addition to removing your contacts before swimming, showering, or sleeping, you should also refrain from reusing saline solution, make sure your contact case is completely clean and dry before filling it with more solution, and check out these other tips.

[h/t Popular Science]