There has been an increase in recent years in the number of eye infections caused by the rare but dangerous Acanthamoeba parasite. These infections can be very difficult to treat and sometimes lead to blindness.

Contact lens wearers usually are the victims, because Acanthamoeba can attach itself to the surface of a contact lens and then enter the eye through tiny cuts in the cornea. Contact ­lenses can cause some of these tiny cuts (microtrauma).

Three things contact lens wearers can do to stay safe…

Remove your lenses before showering, bathing and swimming. Acanthamoeba can live in tap water…swimming pool water…hot tub water…and even in natural bodies of water, both fresh and salt. This danger exists even if the water has been treated by a local water district and is perfectly safe to drink…and even if swimming pool water has been chlorinated. Acanthamoeba can survive these treatments, and infections have been increasing since 2004. Previously there were one to two cases per million American contact lens ­wearers. Now there are about 15 cases per ­million. It is not clear what is causing the increase.

Remove and thoroughly disinfect your lenses as soon as possible if they are exposed to water. Peroxide cleaning systems are the only type that have been shown to kill Acanthamoeba.

Never use tap water to rinse off lenses or lens cases. ­