Contact Lens Infections

Improperly used contacts can cause infections

woman putting contact lens in her eye
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She was back in the emergency room. Her eye was acting up, again. The world was blurry. It was all because of the contact lenses she had worn - a year before. 

A pair zombie white eyes, a set of yellow slit snake eyes, a unique turquoise lens - all seem like harmless Halloween fun. It was just a bit of dress up. Contact lenses, however, are medical devices; if used improperly, they can be dangerous.

 Not washing contact lenses properly and then inserting them can place infections right onto the eye.

Contact Lenses can cause a serious infection if not cared for properly. They can increase the risk of keratitis. This is an inflammation of the cornea, which is the dome above the iris (the colored part of the eye). 

The warning signs for Keratitis (a serious eye inflammation) with Contact Lenses are:

  • Decreased, Blurry, or Lost Vision
  • Red or pink eye
  • Pain in or around eyes, even after taking out contacts
  • Pain when looking at lights (light sensitivity)
  • New discharge from eyes or watery eyes
  • Sensation of something in the eye

See your doctor or an Eye Doctor if any worrisome symptoms like these develop with Contacts.

To avoid ill-fitted or dangerous contacts, the FDA reminds us that these are medical devices that require a prescription. This involves having an eye exam with eye measurements for prescription lenses.

A prescription should be obtained and the contact lens seller should require this prescription. Contacts should not be lent, borrowed, or shared. They should be cared for properly and the prescriber should explain their proper care.

They are not cosmetics or over-the counter purchases. They are not "one size fits all".

A poor fitting contact or one that isn't hygienic can damage the eye. Colorful contacts sold at Halloween without a prescription are sold illegally.

There are 4 main types of infections: 

These infections can be serious and should be cared by an eye doctor.


Bacteria, including Staphylococcus Aureus (such as MRSA) and Pseudomonas aeruginosa, can infect the eye from contact lenses. These bacteria spread from the skin or water when a contact is not cleaned correctly. Infections require medical attention for antibiotic treatment, such as with prescription antibiotic eye drops.

Risks include: overnight wear, using rigid lenses to correct nearsightedness, not washing lenses or cases well, storing or washing lenses in water, or sharing lenses.


A very rare parasite, Acanthamoeba keratitis, or AK, can cause an eye infection that leads to vision loss, even blindness. It is caused by an Acanthamoeba which is an ameba, a one-celled organism.

Most Acanthamoeba infections, 85% in the US, occur in contact lens wearers.This infection can come from using tap water when washing contact lenses.

Lenses should be rinsed and stored in recommended lens solution, with no added Tap Water. Swimming or going into a hot tub while wearing contacts can also lead to infection, as can trauma to the eye.

Diagnosis early is important, as the infection is difficult to treat even when diagnosed. Treatment requires an eye doctor and prescription eye medications.

This is not spread by drinking tap water or by having contact with steam.

Risks include:  using tap water to wash contact lenses or to dilute the lens solution. Swimming or hot tubbing can also be a risk.


Oral herpes (HSV-1 mouth sores) can spread to the eye from pre-existing herpes blisters. Do not touch your eye without proper hand washing, especially if you have cold sores or herpes blisters around your mouth or elsewhere.

Risks include: touching your eyes without washing your hands, especially if you have cold sores.


The risk of fungal keratitis is increased by contact use. It can happen after eye trauma from plants, such as thorns or sticks, getting into the eye.  Those with immune system or eye disease are at more risk.

There was an outbreak of Fusarium keratitis in 2006 due to a specific contact lens solution, later withdrawn from the market. Other types of fungal infections include Aspergillus and Candida.

Risks include: In rare cases, certain contact lens solutions can be contaminated by fungus - and should be removed fro the market.

Safe Use

Even when lenses are legally obtained, infections still happen. The misuse of contacts that can lead to infections. Washing or storing lenses in Tap Water can spread infections.

In order to avoid this risk, there are basic rules:

  • Remove lenses if there is pain, redness, or irritation
  • Wash hands well with soap and water before changing lenses
  • Clean lenses and cases well with cleaning solution
  • Do not use Tap Water to clean lenses or cases
  • Do not top off cleaning solution with Tap Water
  • Do not store lenses in Tap Water
  • Avoid showering, swimming, or using a hot tub with contacts unless discussed with your eye doctor
  • Do not wear lenses overnight unless prescribed
  • Do not share lenses
  • Follow up with an eye doctor regularly and if there is a problem

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