Eye health professionals strongly recommend against swimming while wearing contact lenses. Lenses are precisely fitted medical devices placed directly on the corneal surface, and exposure to any water source creates a serious risk of contamination and infection. Water, even if it appears clean, can harbor microorganisms that become trapped against the eye, bypassing natural defense mechanisms. This practice is consistently flagged by organizations like the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) as significantly compromising ocular health.
How Water Sources Introduce Contaminants
Water from any source, including pools, lakes, oceans, hot tubs, and tap water, is non-sterile and contains various microorganisms. Soft contact lenses are particularly susceptible because their porous material allows them to absorb water like a sponge, along with any dissolved chemicals or microbes. Once saturated, the lens material swells and changes shape. This change can cause the lens to adhere tightly to the cornea, making it difficult to remove and potentially causing microscopic abrasions.
The physical presence of the lens on the eye creates a barrier, preventing the natural flow of tears that would typically flush out foreign particles. Trapped contaminants are held directly against the sensitive corneal tissue for prolonged periods. Even though pool water contains chlorine, this chemical does not eliminate all pathogens, particularly the hardier organisms. This mechanism transforms the lens into a localized reservoir for infection, dramatically increasing the risk compared to swimming without contacts.
Specific Eye Health Risks
The direct consequence of water contamination is a heightened risk of severe ocular infections, primarily a condition known as microbial keratitis. This is an inflammation of the cornea caused by bacteria, fungi, or amoebae trapped beneath the lens. Among the most dangerous is Acanthamoeba keratitis, a rare but devastating infection caused by a microscopic amoeba commonly found in water sources.
Symptoms often begin with severe eye pain, disproportionate to visual findings, accompanied by intense redness and increased sensitivity to light. Patients may also experience blurred vision and the persistent sensation of a foreign object in the eye. The infection is difficult to treat and can persist for months, sometimes leading to corneal scarring that necessitates a transplant, or permanent vision loss. Beyond infection, exposure to pool chemicals like chlorine can cause non-infectious risks, including intense eye irritation, dryness, and corneal abrasions.
Mitigation Strategies and Safe Alternatives
If swimming with contacts is considered necessary, certain measures can reduce, though not eliminate, the risk. Wearing tight-fitting, sealable swim goggles over the contact lenses provides the most effective physical barrier against water exposure. The goggles must form a watertight seal to prevent contaminated water from reaching the eye and becoming trapped beneath the lens.
Immediately after water exposure, contact lenses must be removed and discarded, especially if they are daily disposable lenses. Reusable lenses require immediate and thorough cleaning, rubbing, and disinfection with fresh solution for a minimum duration, often overnight, to attempt sterilization. The safest alternatives for maintaining clear vision involve prescription-based options that eliminate the need for contacts. Prescription swim goggles or masks provide a secure, watertight seal with lenses custom-matched to the wearer’s visual correction.