Can I use tap water on my contact lenses or case?

Tap water — including filtered tap water and most bottled water — is the single biggest avoidable risk factor for contact-lens-related infections.

The danger is Acanthamoeba keratitis, a parasitic infection of the cornea. It is rare but devastating: months of intensive treatment, often a corneal transplant. The parasite lives in tap water at levels harmless for drinking but problematic on a contact lens that holds it against the cornea for hours.

The rules:

• Never rinse a lens, case or hands-just-before-handling with tap water.
• Never wear lenses in the shower, hot tub or while swimming without sealed goggles.
• If you must touch your lens after touching water, rinse the lens with multi-purpose or saline before reinsertion.

"Boiled and cooled" or "filtered" tap water is still not sterile enough for lens contact. Always use commercial solution or sterile saline.