Risks Associated with Cleaning Contact Lenses with Drinking Water

The world of optometry has revolutionized the lives of millions of people with visual impairments thanks to contact lenses. However, it is essential to understand correct hygiene and care practices to avoid potentially harmful complications. A common mistake is the use of drinking water to clean contact lenses, a practice that can have serious consequences for ocular health.

Although drinking water is safe to drink, it is not sterile and can contain microorganisms harmful to the eyes (Kilvington, Gray, Dart, Morlet, Beeching, Frazer, & Matheson, 2004). Some of these microorganisms can be resistant to chlorination processes and other water purification methods. In the ocular environment, these microorganisms can cause serious infections, including Acanthamoeba keratitis, a painful and potentially blinding infection caused by an amoeba called Acanthamoeba (CDC, 2019).

Acanthamoeba is naturally found in water, soil, and air, and is resistant to most conventional water treatment methods. Acanthamoeba infection is rare, but in most cases, it affects contact lens users, particularly those who have exposed their lenses to water (Seal, 2003). The amoeba adheres to the surface of the contact lenses and can be transmitted to the eye, where it can cause a serious infection.

In addition to Acanthamoeba, there are other microorganisms, such as Pseudomonas aeruginosa, which can also cause serious eye infections (Bourcier, Thomas, Borderie, Chaumeil, & Laroche, 2003). Pseudomonas is a bacterium commonly found in water that can cause a rapid and destructive corneal infection. Although rare, this infection can cause permanent damage in a matter of hours.

The most effective way to prevent these infections is to follow the recommendations of eye health professionals and contact lens manufacturers. This includes not exposing contact lenses to water, including tap water, bottled water, sea water, and water from swimming pools or hot tubs. Contact lenses should be cleaned and stored in recommended disinfecting solutions and never reusing or "topping off" old solution (Stapleton, Keay, Edwards, Naduvilath, Dart, Brian, & Holden, 2008).

In conclusion, washing contact lenses with drinking water, although it may seem harmless, can pose a significant risk to eye health. It is crucial for contact lens users to understand this risk and follow care and cleaning recommendations to protect their vision.

References:

1. Bourcier, T., Thomas, F., Borderie, V., Chaumeil, C., & Laroche, L. (2003). Bacterial keratitis: predisposing factors, clinical and microbiological review of 300 cases. British Journal of Ophthalmology, 87(7), 834-838.
2. CDC. (2019). Acanthamoeba Keratitis FAQs. Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/acanthamoeba/gen_info/acanthamoeba_keratitis.html
3. Kilvington, S., Gray, T., Dart, J., Morlet, N., Beeching, J. R., Frazer, D. G., & Matheson, M. (2004). Acanthamoeba keratitis: the role of domestic tap water contamination in the United Kingdom. Investigative Ophthalmology & Visual Science, 45(1), 165-169.
4. Seal, D.V. (2003). Acanthamoeba keratitis update—incidence, molecular epidemiology and new drugs for treatment. Eye, 17, 893–905.
5. Stapleton, F., Keay, L., Edwards, K., Naduvilath, T., Dart, J. K., Brian, G., & Holden, B. A. (2008). The incidence of contact lens-related microbial keratitis in Australia. Ophthalmology, 115(10), 1655-1662.

Dr. Zeyad Zaben

Optometrist, Spain