Disposable contacts can be convenient, as long as they are properly used. But contact lens wearers are also at higher risk for infection.

The Daily Mail reports that  Lian Kao, a 23-year-old college student in Taiwan, lost her eyesight after wearing disposable contacts for six months, even while she was sleeping and swimming.

General guidelines indicate that contact lenses should not be worn for more than eight hours per day. People should not wear their contacts when they come in contact with water, such as in the shower or pool.

Single-cell amoeba, which are microscopic bacteria, gnawed away the corneas, devouring the surface of both of her eyes. The damage is believed to be permanent.

Kao was officially diagnosed with acanthamoeba keratitis. The acanthamoeba adhere to the contact lens surface and then burrow into the corneas.  The condition usually does not cause severe symptoms until the latter stages, when eye damage has already been suffered. In the earlier stages, prescription drugs and corneal transplants are sometimes effective in treating the condition.

Doctors hope this story serves as a reminder to contact lens wearers that proper hygiene is a necessity to protect eye health.