Keratitis is irritation of the cornea. The cornea is the clear, rounded tissue on the front of the eyes that is covering the pupil and the iris. Keratitis can be noninfectious or infectious; the infectious keratitis is usually caused by bacteria, viruses, fungi and parasites; whereas the noninfectious keratitis on the other hand can appear due to minor injury from something simple as wearing contact lenses for a long time..



If a person is experiencing some of the symptoms of keratitis, he/she should see the doctor as soon as possible, because if the keratitis is left untreated it can lead to serious complications or even permanent vision damage.

The symptoms are:

  • Redness
  • Blurry vision
  • Decreased vision
  • Pain
  • Light sensitivity
  • Excess tears (or other discharge)
  • Felling that something is in the eye



The causes for keratitis can be:

  • Injury by scratching the surface of the eye (a noninfectious keratitis may occur, or infectious keratitis if a bacteria makes through the damaged surface)
  • Contamination of the contact lenses (microscopic parasite can inhabit the contact lenses and contaminate the cornea causing infectious keratitis)
  • Virus (such as: herpes simplex, herpes zoster, and the virus that causes chlamydia)
  • Polluted water (chemicals in pools, bacteria, parasites and fungi in rivers, lakes and hot tubs; especially if the cornea is already sensitive and vulnerable by wearing contact lenses for too long for example)


Risk factors

The following factors may increase the risk of keratitis:

  • Wearing contact lenses (if the lenses are not disinfected properly, if they are worn while swimming or for a long period of time, or if water or other homemade solutions are used for cleaning the lenses)
  • Eye injury (previous injury of the cornea, makes the eye more susceptible to keratitis)
  • Warm climate (the risk is higher if a person lives in a place with humid climate; especially if a plant material gets in the eye)
  • Weak immune system because of medications or diseases
  • Using corticosteroid eyedrops



Some potential complications that can occur are:

  • Swelling and scarring of the cornea
  • Corneal ulcer
  • Repeated or chronic infections
  • Chronic inflammation of the cornea
  • Brief or long-lasting vision reduction
  • Blindness



The treatment of both noninfectious and infectious keratitis differs depending on the cause.

For instance, if the keratitis is caused by overtime lens wear (i.e. noninfectious keratitis), the person may only need an eye patch for 24 hours or certain eye medicine.

If the keratitis is infectious, the treatment differs depending on what caused the infection, i.e. if the cause is bacterial, fungal, viral, etc.

  • For bacterial keratitis the infection may be treated only by antibacterial eyedrops, or oral antibiotics if the infection is moderate or severe
  • The fungal keratitis needs to be treated with antifungal eyedrops oral medications
  • If the keratitis is caused by a virus, antiviral eyedrops and oral medications may be effective, but not able to eliminate the virus completely, so the virus can reoccur in the future


  • Acanthamoeba keratitis-is a keratitis cause by the small parasite acanthamoeba. It can be difficult to treat this kind of keratitis. Antibiotic eyedrops can be of some help, but some infections of this kind are resistant to medicines, so the solution for severe cases may be a cornea transplant.



Proper use, cleaning and disinfecting of contact lenses can help prevent keratitis. Some advices to follow include: wear daily contact lenses, take the lenses out before sleeping, handle the contact lenses with clean and dry hands, use sterile products made for contact-lens care, rub the lenses gently when cleaning them, pay attention to the instructions of the eye specialist and follow the recommendations.