You should never wash your contact lens case with water. This practice is a significant risk factor for severe eye infections, making proper contact lens case hygiene essential for maintaining eye health. The case acts as a reservoir; if it becomes contaminated, the harmful microorganisms it harbors are transferred directly to the contact lens and then onto the eye’s surface. Failing to maintain a clean case increases the potential for serious complications that can affect vision. Avoiding water is the first step in establishing a safe contact lens care routine.
Why Tap Water is Unsafe for Contact Lens Cases
Tap water, despite being safe for drinking, is not sterile and contains microscopic organisms that pose a threat to the eye. The primary danger comes from the amoeba Acanthamoeba, which is commonly found in water sources, including tap water, distilled water, and even bottled water. When this amoeba contacts a contact lens case, it can adhere to the plastic and transfer to the contact lens.
This transfer can lead to a rare but serious condition known as Acanthamoeba keratitis, a painful and potentially blinding eye infection. The organism exists in two forms, the active trophozoite and a highly resistant cyst, making it very difficult to eliminate once it contaminates the lens or case. Water also harbors various types of bacteria, such as Pseudomonas aeruginosa and Serratia marcescens, which thrive in moist environments and can cause other serious microbial keratitis infections.
Soft contact lenses are particularly susceptible because their porous material can absorb contaminants and water-borne minerals. The presence of these microorganisms and minerals on the lens can create an environment where a sticky, protective layer called a biofilm forms inside the case. This biofilm shields the microbes, making them resistant to the disinfecting agents in contact lens solutions. Introducing unsterile tap water directly undermines the entire disinfection process and increases the risk of ocular infection.
The Correct Daily Cleaning and Storage Procedure
The correct daily procedure for a contact lens case relies entirely on using fresh, sterile contact lens solution, not water. After removing the lenses, the old solution must be emptied and discarded immediately, as it loses its disinfectant properties. Wearers must never “top off” the old solution by simply adding new solution to the reservoir, as this significantly reduces the effectiveness of the disinfectant.
The next step involves physical cleaning of the case itself. The case should be rinsed thoroughly using only fresh multipurpose solution, which acts as a gentle washing agent. Some practitioners recommend a light “rub and rinse” technique, where the inside surfaces are rubbed with a clean fingertip or wiped with a clean tissue during rinsing to dislodge any residual biofilm or debris.
Once rinsed, the case must be allowed to completely air-dry to inhibit the growth of bacteria and fungi. The best practice is to place the case upside down on a clean, lint-free tissue with the caps removed, which allows for maximum air circulation and drainage. This air-drying step is essential because a moist environment is a breeding ground for microorganisms, even after rinsing with a disinfecting solution.
Knowing When to Replace Your Contact Lens Case
Even with perfect daily hygiene, the contact lens case has a limited lifespan and must be replaced regularly. The standard recommendation from eye care professionals is to replace the case at least every three months. This schedule is necessary because the plastic material develops microscopic scratches and becomes a site for stubborn biofilm accumulation over time.
The complex structure of the mature biofilm makes it nearly impossible to remove completely with routine cleaning, turning the old case into a continuous source of potential contamination. Replacing the case every three months ensures that a fresh, non-colonized surface is used to store and disinfect the lenses. However, replacement should occur sooner if any signs of material degradation are noticed. Visible indicators like cracks in the plastic, discoloration, or any residue that cannot be cleaned away signal that the case’s protective integrity has been compromised and it should be discarded immediately.