Contact solution is sterile and is specially designed to clean and disinfect your lenses. Tap water doesn’t share the disinfectant properties of contact lens solutions. In fact, water allows bacteria and harmful pathogens to stick to your contacts. Water often contains amoebas, single-celled organisms that have the ability to change shape. One particular type of amoeba, known as acanthamoeba, is typically found in tap water, well water, lake water, and other sources. Acanthamoeba can cause a severe eye infection known as acanthamoeba keratitis. “Acanthamoeba keratitis is one of the most challenging infections that we treat in ophthalmology,” Dr. Dhaliwal says.