Do You Wear Contact Lenses?

There's something you should know…

More than 34 million people in the U.S. and 71 million people in the world wear contact lenses. Contact lens wearers include athletes, actors, musicians, and people in occupations where glasses get in the way. Some people wear contacts for cosmetic reasons.


What is Acanthamoeba?

Pronounced A·can·tha·moe·ba, acanthamoeba is a microbe that is very common in the environment, including in tap water. It has two forms: the trophozoite and the cyst. The infective form is the trophozoite, which can change into a cyst and survive a long time. These trophozoites and cysts can stick to the surface of your contact lenses and then infect your eye.

What are the symptoms of Acanthamoeba eye infection?

Symptoms include severe pain in the eye, the sensation of a foreign body in the eye, and a whitish halo at the periphery of the eye. The infection cal last weeks to months, and it never fully heals despite treatment. See your doctor immediately if you experience any of these symptoms. You can locate a contact lens doctor by visiting the website for the Contact Lens Association of Ophthalmologists Exit.

How do you get Acanthamoeba on your contact lenses?

Acanthamoeba gets on your lens when you use contaminated or homemade lens solutions to rinse or store your lenses. Eye infections often result when the microbe attaches to the surface of the lens and the contact case. You can also get infected when you swim while wearing your contact lenses.

Who can get infected?

  • Anyone who wears contact lenses and does not use proper lens care.
  • Teens who share and swap their colored lenses.
  • People who use homemade saline solutions for contact lenses.
  • People who do not disinfect their contact lenses.
  • People who use saliva to wet their contacts.
  • People who buy contacts at beach shops and flea markets without going to the eye doctor for a prescription.

Can Acanthamoeba eye infection be treated?

This infection is difficult to treat. A doctor can successfully treat it with a combination of topical ointments such as Brolene and PHMB. You can locate a contact lens doctor by visiting the website for the Contact Lens Association of Ophthalmologists Exit.

How can I prevent an Acanthamoeba eye infection?

  • Practice good personal hygiene when handling your contact lenses.
  • Remind young contact lens wearers about proper lens handling.
  • Clean, rinse, and disinfect lenses with commercially made sterile solutions before placing them in the eyes.
  • Clean lens cases with commercially made sterile solutions.
  • Don’t use tap water, homemade solutions, and other non-sterile solutions to disinfect and store contacts.
  • Don’t wet lenses with saliva.
  • Follow manufacturer instructions in rinsing and storing contact lenses.
  • Don’t swim while wearing your contacts.
  • Don’t trade, share, or borrow another person’s lenses.
  • Replace lenses and lens cases as often as possible.
  • Only wear contact lenses prescribed by an eye care professional.

What is EPA doing about Acanthamoeba?

We have issued a guidance for vision care and health care providers on Acanthamoeba in contact lens wearers. An EPA fact sheet also provides condensed information for public awareness on Acanthamoeba.

Additional Materials and Guidance

The Centers for Disease Control (CDC) has good information on acanthanmoeba, including frequent questions.

Guidance Documents

Fact Sheets

  • “Acanthamoeba: What Vision Care and Health Care Providers Should Know” (EPA-822-F-04-003)
  • “Lo que deben saber quienes cuidan de la vista y de la salud” (EPA-822-F-04-004)

Brochures for the Public

  • “Preventing Acanthamoeba Eye Infection in Contact Lens Wearers” (EPA-822-F-04-005)
  • “Do You Wear Contact Lenses? There’s Something You Should Know” (EPA-822-F-04-006)
  • “¿Usas Lentes de Contacto? Hay Algo Que Debes Saber” (EPA-822-F-04-007)

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