Many contact lens wearers wonder if they can extend the life of their daily disposable lenses by cleaning and storing them in solution overnight, often hoping to reduce costs. A daily disposable lens is specifically engineered to be worn for a single day and then immediately discarded. The design dictates that the lens is meant for one-time use only, eliminating the need for cleaning steps. This article addresses the reuse of these lenses, focusing on design principles, material limitations, and the health risks associated with improper storage and re-wear.
Daily Disposables: The Single-Use Design
The direct answer to whether a daily disposable lens can be stored in solution for reuse is no. These lenses are classified by the U.S. Food and Drug Administration (FDA) as single-use medical devices. They are intended to be worn for one period and thrown away immediately upon removal, meaning they should never be cleaned, disinfected, or stored, regardless of the solution used.
The convenience of daily disposables is built upon this disposable nature, bypassing the need for lens care solutions, cases, or nightly cleaning routines. This model provides the highest level of hygiene, as a fresh, sterile lens is placed on the eye each morning. Attempting to reuse a daily lens defeats the purpose of the design and introduces risks the material is not equipped to handle.
Material Differences That Prevent Storage
Daily disposable lenses are constructed from materials fundamentally different from those used in bi-weekly or monthly reusable lenses. They are made to be extremely thin and flexible, which enhances initial comfort but makes them highly susceptible to damage. This thin structure means the lens is prone to micro-tears and scratches simply from the physical handling and rubbing involved in a cleaning process.
The surface of a daily disposable is not engineered to resist the buildup of tear film components, such as proteins and lipids. The material is designed to allow these deposits to accumulate quickly since the lens is meant to be discarded before they become problematic. Standard multipurpose cleaning solutions are ineffective at removing these embedded deposits from the delicate material. Furthermore, trying to clean them can cause the lens to break down, compromising its integrity for a second day of wear.
Ocular Health Risks of Reuse
The most serious concern with reusing daily disposable lenses is the increased risk of microbial contamination and eye infection. Since the lens material is not designed for repeated disinfection, storing a used lens in a case, even with fresh solution, creates a breeding ground for bacteria. Studies have shown that a high percentage of worn daily disposable lenses stored overnight were contaminated with harmful microorganisms like Staphylococcus aureus.
Re-wearing a lens covered in deposits and microbes can lead to severe conditions such as keratitis, an inflammation of the cornea that can cause significant pain and vision loss. The accumulated protein and lipid deposits also block the lens’s ability to transmit oxygen efficiently to the cornea on the second day. This oxygen deprivation, known as corneal hypoxia, can lead to swelling and compromise the eye’s natural defenses. Unremoved deposits also trigger inflammatory responses, which can manifest as irritation or allergic reactions.