Acanthamoeba is one of the most common organisms in the environment. Although it rarely causes infection, when it does occur, it can threaten your vision.
Irritated eye - eye infection - keratitis

Recently, there have been increased reports of Acanthamoeba keratitis. The best defense against this infection is proper contact lens hygiene.

Causes & risk factors

  • Using tap water to clean and disinfect contact lenses, including the lens case.
  • Swimming with contact lenses, especially in freshwater lakes and rivers.

Acanthamoeba keratitis has been found in almost all water sources from pools to hot tubs and showers. Failure to follow contact lens care instructions could lead to infection.


  • A red, frequently painful eye infection that doesn't improve with traditional treatment.
  • Feeling of something in the eye, excessive tearing, light sensitivity, and blurred vision.
  • Red, irritated eyes that last for an unusually long time after removing your contact lenses.


The best course of action is to see a doctor of optometry with symptoms. Do not hesitate to tell your doctor of improper contact lens or case care, as accurate information can lead to a precise diagnosis and proper treatment.

  • Doctors will use the patient's history, symptoms and lens-care habits to determine if the patient has Keratitis.
  • Pain is typically out of proportion to signs.
  • The doctor will perform a complete eye health examination and may order lab tests or consider a biopsy.


  • Topical agents applied to the infected area over months.
  • Removal of damaged tissues.
  • The doctor may consider a biopsy if the condition worsens.


  • Always wash hands before handling contact lenses.
  • Rub and rinse the surface of the contact lens before storing.
  • Use only sterile products recommended by your doctor of optometry to clean and disinfect your lenses. Saline solution and rewetting drops are not designed to disinfect lenses.
  • Avoid using tap water to wash or store contact lenses.
  • Contact lens solution must be discarded upon opening the case, and fresh solution used each time the contact lens is placed in the case.
  • Replace lenses using your doctor’s prescribed schedule.
  • Do not sleep in contact lenses unless prescribed by your doctor and never after swimming.
  • Never swap lenses with someone else.
  • Never put contact lenses in your mouth or use saliva to wet the contact lens.
  • See your doctor of optometry regularly for contact lens evaluation.
  • If you experience RSVP (redness, secretions, visual blurring or pain), return to your doctor of optometry immediately.
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