Contact lenses are not designed for water exposure. Eye care professionals advise against wearing them while swimming or showering because all water sources—including chlorinated pools, oceans, and tap water—contain microorganisms and chemicals. These contaminants pose a threat to eye health when trapped against the cornea by a contact lens. Soft contact lenses are particularly susceptible because their porous material absorbs water, which can carry contaminants directly to the eye’s surface.
The Immediate Danger: Acanthamoeba Keratitis
The most severe consequence of water exposure is the risk of contracting Acanthamoeba keratitis, a rare but potentially sight-threatening parasitic infection. This condition is caused by the Acanthamoeba parasite, a microscopic amoeba commonly found in water sources worldwide, including lakes, oceans, soil, and even treated municipal water supplies. The amoeba exists in a highly resistant cyst form, making it difficult to eliminate even with standard disinfectants like chlorine.
When a soft contact lens is exposed to water containing this parasite, the amoeba can adhere to the lens surface and become trapped between the lens and the eye. Contact lens wear can cause tiny, microscopic abrasions on the cornea, which then act as entry points for the parasite to invade the eye tissue. Once inside, the amoeba can begin to consume the corneal tissue, leading to an extremely painful and destructive infection.
Symptoms of this infection include severe eye pain, intense light sensitivity, blurred vision, and a sensation that something is lodged in the eye. Diagnosis can be difficult in the early stages, and treatment often requires a lengthy regimen of specialized medications that can last for months or even a year. If not treated early and aggressively, the infection can lead to permanent visual impairment, the need for a corneal transplant, or, in rare cases, blindness.
General Risks: Chemical Irritation and Lens Adherence
Swimming with contact lenses introduces common physical and chemical irritations to the eye. Pool water contains chlorine and other chemicals that bind to the porous material of a soft lens. This chemical residue can cause immediate irritation, redness, and a dry eye sensation once the lens is worn out of the water. Saltwater from the ocean can similarly dehydrate the lens and disrupt the natural tear film that protects the eye’s surface.
Water absorption also physically changes the contact lens itself, which can lead to mechanical problems on the eye. Soft lenses swell and change shape when immersed in water, often causing them to tighten or suction onto the cornea. This adherence can make the lens difficult to remove and may lead to painful corneal abrasions. These microscopic injuries create an easy entry point for common waterborne bacteria, such as Pseudomonas aeruginosa, which can cause acute, painful corneal ulcers and bacterial keratitis.
Immediate Action Steps
If you accidentally wore your contact lenses while in the water, action is necessary to minimize the risk of irritation or infection.
Steps to Take Immediately
- Wash your hands thoroughly with soap and water before attempting to touch your eyes or lenses.
- Remove the contact lenses immediately upon leaving the water.
- If you wear daily disposable lenses, discard them instantly and replace them with a fresh pair or switch to glasses.
- For reusable lenses, they must be thoroughly cleaned and disinfected by rubbing, rinsing, and soaking them in a fresh, multipurpose solution for a full overnight cycle.
- Use preservative-free artificial tears to gently flush the eyes and remove any microscopic debris or irritants.
If your eye remains red, painful, or you experience blurred vision for more than a few hours, seek an immediate examination from an eye care professional. These persistent symptoms could indicate the start of a serious infection requiring prompt treatment.
Safe Water Alternatives
The most effective way to prevent water-related eye complications is to avoid wearing contacts during any water activity. For those needing vision correction, prescription swimming goggles are the safest alternative, as they provide clear underwater vision while creating a watertight seal that keeps contaminants away from the eyes.
If prescription goggles are not an option, choosing to wear a fresh pair of daily disposable lenses for swimming is recommended. Discarding the contaminated daily lenses immediately after swimming eliminates the risk of waterborne pathogens remaining on the lens for future wear. Carrying a spare contact lens case with fresh solution and a backup pair of glasses ensures you are prepared to safely remove your lenses if water exposure occurs unexpectedly.