When a contact lens solution runs out, the situation requires immediate and cautious action to protect eye health and maintain lens integrity. Contact lenses must be kept in a sterile, pH-balanced liquid that is specifically designed to clean, disinfect, and hydrate them. Since the delicate environment of the eye is highly susceptible to infection, it is important to understand that no common household liquid can serve as a true, long-term substitute for commercial lens solution. Approaching this issue requires prioritizing eye safety and understanding the difference between temporary moistening and actual disinfection.
Immediate Temporary Substitutes
The safest short-term liquids available are those already approved for ocular use, such as sterile, sealed saline solution. This solution is specifically formulated to rinse the lens and keep it hydrated, matching the salinity of human tears. It is important to note that sterile saline is only a rinsing or moistening agent and lacks the necessary ingredients to effectively disinfect the lens.
Another acceptable option is preservative-free artificial tears, often called lubricating eye drops, which can be used to keep a lens moist for a very brief period. These drops are sterile and designed to be compatible with the eye’s surface, preventing the lens from drying out and warping. Neither saline nor artificial tears should be relied upon for cleaning or storage beyond the immediate emergency, such as a short trip to a pharmacy. If the lens is stored in these liquids, it must still undergo a full disinfection cycle before re-insertion.
Critical Safety Warnings
You must never use tap water, bottled water, or distilled water to rinse or store contact lenses. Tap water, even if potable, contains numerous microorganisms, including a microscopic amoeba called Acanthamoeba. This organism is a primary cause of Acanthamoeba keratitis, a painful and sight-threatening corneal infection.
Tap water is also hypotonic, meaning it has a lower salt concentration than the lens material and the eye’s natural tear film. This osmotic imbalance causes soft contact lenses to absorb water and dramatically swell. The change in the lens’s shape and size can cause it to adhere tightly to the cornea, making removal difficult and potentially creating microscopic abrasions on the eye’s surface.
Never attempt to use saliva, as the human mouth is a rich source of bacteria that can be easily transferred to the lens and cause severe eye infections. Similarly, homemade saline solutions should be avoided because they cannot guarantee the sterility or the precise pH and osmolarity required for safe contact lens care.
Emergency Overnight Storage Protocol
The ideal course of action for lenses that must be removed without proper solution is to discard them immediately, especially if they are daily disposable lenses. If the lenses are expensive or intended for extended use and must be saved, the goal is to keep them from drying out until a proper solution can be obtained. Wash your hands thoroughly and place the lenses in a clean, sealed contact lens case.
The case should be filled with sterile saline or preservative-free artificial tears to hydrate the lenses overnight. If no acceptable sterile liquid is available, the last resort is to store the lenses completely dry in the sealed, clean case. Although this risks the lenses drying out, shrinking, and warping, it avoids the severe infection risk posed by water.
Any lens stored without a proper multipurpose or hydrogen peroxide disinfecting solution is considered contaminated. Before wearing, the lenses must be soaked in a fresh disinfecting solution for the entire manufacturer-recommended period, which is typically six to eight hours.