Water and contact lenses are a dangerous combination. Eye care professionals universally advise against letting your lenses touch any type of water, including tap water, pool water, showers, or hot tubs. Contact lenses are medical devices maintained with sterile solutions, and exposure to non-sterile water introduces both a physical hazard to the lens material and a significant biological risk to the eye. Understanding these specific dangers is the first step toward maintaining healthy vision while wearing contacts.
How Water Physically Affects Contact Lenses
Soft contact lenses are engineered to be hydrated by specialized contact lens solutions which are isotonic, meaning they have a salt concentration balanced with the natural environment of the eye. Plain water, however, is hypotonic, containing a lower salt concentration than the lens material itself. When exposed to water, the lens begins to absorb it through osmosis.
This rapid absorption causes the lens to swell significantly, altering its shape and changing how it fits on the cornea. A misshapen lens can cause acute discomfort, blur vision, and potentially adhere tightly to the eye’s surface. When the lens sticks to the cornea, removing it can cause corneal abrasions, creating a potential entry point for harmful microorganisms. Furthermore, mineral deposits found in tap water can bind to the lens surface, leading to irritation and reduced clarity.
Pathogens Found in Water Sources
Beyond the physical damage, the greatest risk from water exposure is the introduction of microorganisms that thrive in non-sterile environments. Tap water, showerheads, hot tubs, and natural bodies of water are not sterile and often contain bacteria and parasites that pose a severe threat. These organisms can easily adhere to the porous surface of a contact lens, becoming trapped between the lens and the delicate corneal tissue.
The most concerning of these is Acanthamoeba, a microscopic, free-living amoeba commonly found in water and soil. This organism is particularly dangerous because it can transform into a highly resistant cyst form, allowing it to survive harsh conditions. Other common waterborne bacteria, such as Pseudomonas aeruginosa, can also attach to the lens and multiply rapidly, bypassing the eye’s natural defenses and leading to serious complications.
Serious Eye Infections Resulting from Water Exposure
The introduction of waterborne pathogens can lead to severe and vision-threatening conditions, collectively known as microbial keratitis. One of the most devastating forms is Acanthamoeba Keratitis (AK), an infection of the cornea caused by the amoeba discussed previously. AK is often misdiagnosed initially because its symptoms mimic more common eye infections. The infection can cause excruciating pain, severe light sensitivity, blurred vision, and redness.
AK is notoriously difficult and lengthy to treat, sometimes requiring months of intensive medication. If the infection progresses, it can cause permanent corneal scarring, leading to long-term vision loss or requiring a corneal transplant. The bacteria Pseudomonas aeruginosa can cause bacterial keratitis, resulting in a corneal ulcer that progresses quickly and requires immediate medical intervention to prevent permanent vision impairment.
Essential Steps for Safe Contact Lens Care
Protecting your eyes from water-related risks requires strict adherence to proper lens hygiene. Never expose your contact lenses to any form of water, which includes showering, swimming, or using a hot tub while wearing them. Only use a fresh, sterile, commercially prepared contact lens solution recommended by your eye doctor for cleaning, rinsing, and storing your lenses. Never use tap water or saliva as a substitute for solution.
Always clean your contact lens case with fresh solution, not water, and allow it to air-dry completely between uses. Replace your lens case at least every three months to prevent the buildup of biofilms where microorganisms can thrive. If your lenses accidentally come into contact with water, remove them immediately and discard them, or clean and disinfect them in fresh solution overnight. If you experience any pain or redness, seek prompt consultation with an eye care professional.