Contact lenses are medical devices, and their safe use depends entirely on a sterile environment maintained by specialized cleaning solutions. Proper contact lens solution performs three tasks: cleaning the lens surface, disinfecting the material to kill microorganisms, and hydrating the lens to maintain comfort. Running out of solution puts your lenses and eyes at immediate risk because these components require a sterile, pH-balanced medium when not being worn. Without the proper solution, the lens material and the natural tear film are compromised, making the lenses a potential vector for infection.
Why Common Substitutes Are Dangerous
Tap water is a common but dangerous choice because it is not sterile and often contains microorganisms, including the sight-threatening parasite Acanthamoeba. If this amoeba contaminates the lens and is introduced to the cornea, it can cause Acanthamoeba keratitis, a severe infection that is difficult to treat and can lead to permanent vision loss. Furthermore, tap water is a hypotonic solution, meaning it has a lower salt concentration than tears and lens material. When a soft contact lens is placed in tap water, the lens absorbs the water, causing it to swell, distorting its shape and potentially damaging the corneal surface.
Saliva is another unsafe option because the human mouth is home to a dense population of bacteria. Transferring saliva to a contact lens introduces a high concentration of oral flora, such as Streptococcus or Pseudomonas, directly onto the lens surface. These organisms can quickly multiply and cause aggressive eye infections, including bacterial keratitis, which can rapidly progress and result in corneal ulceration. The enzymes in saliva are also not balanced for the eye’s environment, which can damage the lens material.
Attempting to create a homemade saline solution by mixing salt and water fails to meet the necessary safety standards for contact lens care. While this mixture may mimic the tonicity of tears, it lacks the disinfecting agents and buffers found in commercial solutions. Crucially, it is not sterile, meaning it can still harbor bacteria and other pathogens that are transferred to the eye. The only way to ensure a solution is truly sterile and properly balanced for disinfection is to use a commercially manufactured product.
Safest Temporary Measures for Lens Handling
When you are without proper solution, the safest course of action is to immediately remove and discard your contact lenses, then switch to wearing glasses. Lenses that have been removed and not properly disinfected should be treated as contaminated and must not be reinserted into the eye. If you must preserve the lenses, the immediate goal is simply to keep them hydrated until they can be properly disinfected.
If you have sterile, unpreserved saline solution (sold in small vials for rinsing), it can be used for temporary storage, but only for up to 24 hours. This sterile saline is only a rinsing agent and does not contain the necessary chemicals to clean or kill microorganisms. After temporary storage, the lenses must be thoroughly cleaned, rubbed, and soaked in fresh, disinfecting solution for the full recommended time before re-wearing.
Rigid gas permeable (RGP) lenses are more durable and less absorbent than soft lenses. The safest temporary measure for overnight storage is to clean them briefly and then place them into a clean, dry case. This dry storage method prevents the lens from harboring bacteria in a non-disinfecting liquid. Before re-inserting, RGP lenses must be cleaned and soaked in their specific disinfecting solution as directed by your eye care professional.
What to Do Next
Your immediate next step is to procure a new bottle of disinfecting contact lens solution as quickly as possible. Many large retail stores, supermarkets, and 24-hour pharmacies often stock travel-sized bottles of multipurpose solution, which can serve as an emergency supply. Convenience stores and gas stations are less reliable but may carry basic eye care products that can provide a short-term fix. Always check the expiration date and ensure the solution is compatible with your lens type before purchase.
Once the immediate crisis is resolved, focus on future preparedness to prevent this situation from recurring. Assemble an emergency kit containing a travel-sized bottle of solution, a spare contact lens case, and a small container of lubricating or sterile saline drops. This kit should be kept in a car, bag, or office desk, ensuring you have a backup supply outside of your home.
You must closely monitor your eyes for any signs of irritation or infection if you wore a lens that was stored improperly. Symptoms to watch for include persistent redness, pain that does not resolve quickly, blurred vision, or increased sensitivity to light. If any of these symptoms appear, remove your lenses immediately and seek prompt medical attention from an eye care professional to rule out a serious corneal infection.