Realizing you are without contact lens solution can cause panic, but attempting a quick substitute is a serious health risk. Contact lenses are medical devices requiring a specialized, sterile solution for proper cleaning, rinsing, and disinfection. Using improper liquids carries a severe risk of permanent eye damage. Your immediate action should be to remove the lenses and switch to glasses, as incorrect cleaning or storage can introduce dangerous microorganisms.
Why Standard Contact Solution Is Non-Negotiable
Commercial contact lens solution is a complex, multi-functional product engineered to maintain lens safety and integrity. The formulation performs three distinct actions: cleaning, rinsing, and disinfection. This multi-purpose fluid contains surfactants, which are specialized agents that lift and remove debris, protein deposits, and lipids accumulating on the lens surface.
The disinfecting component, often chemical agents or hydrogen peroxide, neutralizes harmful microorganisms like bacteria and fungi. The solution is also carefully pH-balanced to be isotonic, matching the eye’s natural osmotic pressure. This composition prevents the lens material from swelling or shrinking, which could cause a poor fit, discomfort, and corneal irritation.
The Absolute Worst Substitutes to Avoid
Using common, non-sterile liquids as substitutes can have immediate and severe consequences. These alternatives introduce contaminants directly onto the lens surface, which is then pressed against the sensitive cornea.
Tap water is one of the most dangerous substitutes because it is not sterile. It frequently harbors Acanthamoeba, a microscopic organism that causes a devastating eye infection known as Acanthamoeba keratitis. This parasitic infection is difficult to treat and can lead to severe pain, permanent vision loss, or the need for a corneal transplant. The lack of salinity in tap water also causes the lens to swell, potentially leading to microscopic corneal abrasions that allow the amoeba to enter.
Saliva is a highly risky substitute because the human mouth contains a large, diverse population of bacteria. Using saliva to wet or rinse a lens transfers these non-sterile microorganisms directly to the eye. Common oral bacteria, such as Pseudomonas aeruginosa, can rapidly colonize the lens and cause aggressive bacterial keratitis.
Homemade saline solutions, made by mixing table salt and water, are profoundly unsafe. While intended to mimic the saline content of tears, it is impossible to ensure the mixture is truly sterile or correctly balanced outside of a laboratory. Non-sterile water or contaminated salt can introduce hazardous pathogens found in tap water, including Acanthamoeba, directly to the lens.
Safe, Short-Term Emergency Rinsing Options
In an emergency where immediate rinsing is necessary, such as removing a speck of dust, there are limited, temporary options, but none are a substitute for disinfection. The best option is a commercially prepared, sterile saline solution. This fluid is designed only for rinsing and does not contain the necessary disinfecting agents to kill pathogens.
Sterile saline can be used for a brief rinse to remove small foreign particles before reinserting a lens. Similarly, unexpired rewetting drops, which are designed to hydrate the eye while the lens is worn, can be used for momentary moisture. Neither option should be used for cleaning or overnight storage, as they lack the chemical components required for true disinfection.
If you must remove and store a lens without proper solution, it is safest to discard it immediately, especially if it is a daily disposable lens. If the lens is intended for extended wear, it can be placed in a sterile lens case and covered with fresh, sterile saline for a few hours at most. The lens must then be thoroughly cleaned and soaked in a proper disinfecting solution for the full recommended cycle, typically six to eight hours, before wearing it again.
Risks of Improper Lens Handling and Storage
Misusing lenses by using improper substitutes or neglecting hygiene increases the risk of severe ocular complications. The most serious outcome is microbial keratitis, an infection of the cornea caused by bacteria, fungi, or parasitic amoebas. These infections progress rapidly, causing intense pain, light sensitivity, and vision loss.
Untreated or poorly managed infections can lead to corneal ulcers, which are open sores on the eye’s surface, resulting in permanent corneal scarring and vision impairment. In some cases, the damage is so extensive that a corneal transplant is required to restore sight.
Beyond infection, using non-specialized liquids compromises the physical integrity of the lens. Solutions that are not isotonic or pH-balanced can cause the lens material to swell or warp, leading to an improper fit. A poorly fitting lens can rub against the cornea, causing abrasive injuries or reducing oxygen flow, which may lead to corneal hypoxia and inflammation.