Using tap water for lens cleaning and wearing lenses while showering can leave contact lens wearers open to infections, U.S. ophthalmologists warn. Study authors Drs. Danielle Robertson and Dwight Cavanagh, ophthalmologists at the University of Texas Southwestern Medical Center in Dallas, said many of the 35 million people in the United States who wear contact lenses risk infection and other complications because they don't know how to care for or wear them. The most common risky behavior is not replacing lens solution daily; exposing lenses to tap water; not replacing storage cases; and not washing hands before handling lenses. The ophthalmologists said using tap water for lens cleaning and wearing lenses while showering can leave contact lens wearers open to infections that could result in substantial vision loss if not identified early. The ophthalmologists also recommend to: