No, you cannot use water as a contact solution. Water, whether from the tap, bottled, or distilled, should never be used to clean, rinse, or store contact lenses. The fluids required for lens care are specifically formulated to maintain eye health and lens integrity, a function water cannot perform. Using water introduces significant risks of infection and can cause physical damage to the lenses themselves.
The Immediate Danger of Using Water
The primary risk of using water with contact lenses is the introduction of dangerous microorganisms, even if the water appears clean. Tap water, bottled water, and distilled water commonly contain the microscopic organism Acanthamoeba. This parasite can attach to the contact lens and infect the cornea, leading to a severe, sight-threatening condition known as Acanthamoeba keratitis. This infection sometimes results in permanent vision loss or blindness.
Beyond the biological threat, water presents a physical danger to the contact lenses and the eye due to a principle called tonicity. Soft contact lenses maintain their shape and fit in an isotonic solution, which has a salt concentration similar to the eye’s natural tears. Pure water is hypotonic (less salty), causing the lens material to absorb the water and swell.
This swelling changes the lens’s shape, leading to an improper fit that can cause discomfort and scratch the delicate surface of the cornea. A scratch on the cornea makes it easier for bacteria and parasites to enter the eye and establish a severe infection.
How Commercial Solutions Protect Your Eyes
Commercial contact lens solutions are complex chemical mixtures designed to perform multiple functions that keep both the lenses and the eyes healthy. The first function is disinfection, which involves killing harmful germs like bacteria, fungi, and amoebae that accumulate on the lens surface during wear. Multipurpose solutions use chemical agents, while hydrogen peroxide systems use oxidative agents.
Solutions are also formulated to clean the lenses by removing deposits that build up over time. They contain surfactants that break down and lift away proteins, lipids, and debris from the lens. This cleaning action is necessary because these deposits can irritate the eye and reduce visual clarity.
Another element is the storage and hydration function, ensuring the lens remains moist and maintains its correct shape. Solutions are buffered and balanced to be isotonic, preventing the lens from swelling or shrinking. This maintains a comfortable and safe fit on the eye.
Emergency Steps When Solution Is Unavailable
If you find yourself without contact lens solution, the safest action is to remove your contact lenses immediately. If the lenses are reusable, the best temporary measure is to store them completely dry in a clean contact lens case until you can purchase the proper solution. Storing them dry is preferable to using any non-approved liquid.
You must avoid all common makeshift alternatives, including homemade saline, saliva, or regular eye drops, as none of these can effectively disinfect the lens. Saline is only for rinsing and does not contain the necessary disinfecting or cleaning agents, while saliva introduces a host of oral bacteria to the lens. Using any of these liquids risks contaminating the lenses and setting the stage for a serious eye infection.
Once you obtain the correct solution, you must soak the lenses for the minimum recommended disinfection time before wearing them again. Keep a small, travel-sized bottle of solution with you at all times, especially when traveling. For those who frequently run out, switching to daily disposable lenses eliminates the need for solution or storage care.