Acanthamoeba Keratitis is a vision-threatening eye infection caused by parasitic, water-dwelling microorganisms called Acanthamoebae. These single-celled protozoa are usually harmless to humans, but if they latch onto a contaminated contact lens, they can infect the cornea causing pain and even blindness.

Incidences are relatively rare – 1 in 30,000 contact lens wearers become infected – but this particular contact lens infection is now on the rise in the UK.  So, to mark Love Your Lenses Week 2019, we’re offering advice on how to prevent the condition…

A 3D representation of the Acanthamoeba parasite


Acanthamoeba Keratitis is caused by the contamination of contact lenses, storage cases and non-sterile solutions.  Several factors can increase your risk of contracting the infection:

  • Using tap water to clean or store lenses
  • Reusing old contact lens solution to store lenses
  • Putting in contact lenses whilst hands are still wet/with unwashed hands
  • Showering/bathing whilst wearing contact lenses
  • Swimming in pools or the sea whilst wearing contact lenses


The symptoms of Acanthamoeba Keratitis are varied. Initially you may experience pain, blurred vision, redness, watery eyes and sensitivity to light, though in the early stages discomfort may be minimal.  However, as the infection progresses, it can affect nerves and deeper parts of the cornea, resulting in severe pain. Without timely treatment, the condition can potentially result in blindness.

A recurring case of Acanthamoeba Keratitis in a 28-year-old


Acanthamoeba Keratitis can be difficult to treat as it isn’t a bacterial infection, so the earlier we diagnose the symptoms the higher your chance of recovery.  If your optometrist suspects you have a contact lens infection, they will immediately refer you to an hospital ophthalmologist who will most likely prescribe medicated antiseptic eye drops to use day and night. Painkillers may be required and additional antibiotics, as Acanthamoeba Keratitis is often accompanied by a bacterial infection.

Severe infections may cause vision-obstructing scarring and require the need for a corneal transplant.


Due to the condition’s difficulty to treat, effective contact lens hygiene is vital to preventing the infection. Here are a few easy steps you can take to reduce the risk:

  • Always clean and dry your hands before handling your contact lenses to avoid contamination
  • Use sterile, in-date solutions to clean and store your lenses to kill any bacteria picked up during hours of wear
  • Always remove your contact lenses before sleeping
  • Never clean or store your lenses with tap water
  • Avoid wearing contact lenses in the shower or bath
  • Avoid wearing contact lenses when swimming in the pool or the sea
  • Think about switching to daily disposable lenses if you are finding it difficult to maintain bi-weekly or monthly contact lenses.
  • If in doubt, always see a qualified contact lens practitioner!

A slit lamp examination with your optometrist gives a good indication of any suspect signs of contact lens infections


If you suspect you’re suffering from symptoms of Acanthamoeba Keratitis, contact us to book an appointment or call us on 0207 224 7400 as soon as possible – one of our highly experienced optometrists will then be able to give you rapid diagnosis and a referral if necessary.