Keratitis is an inflammation and swelling of the cornea, the clear front cover of the eye.

Keratitis may or may not be associated with an infection.

Noninfectious keratitis

Noninfectious keratitis can be caused by an eye injury, by wearing contact lenses too long or by a foreign body in the eye.

Infectious keratitis

Infectious keratitis can be caused by bacteria, viruses, fungi and parasites.

Keratitis can be associated with other eye conditions such as conjunctivitis (pink eye). Keratitis can cause pain, redness and blurred vision. If left untreated or if an infection is severe, keratitis can lead to serious complications that may permanently damage your vision.

Causes & risk factors

Wearing contact lenses increases the risk of developing infectious and noninfectious keratitis, especially if slept in them. Do not wear contact lenses longer than recommended by a doctor of optometry. Follow the cleaning regimen and do not wear contact lenses while swimming, as the chemicals and microbes in the water can cause keratitis.

  • Eye Injury—mechanical (scratch) or chemical (fumes or liquids splashed in the eye).
  • Dry eyes.
  • Overexposure to ultraviolet (UV) light, also called snow blindness.
  • Bacteria.
  • Viruses, most commonly Herpes Simplex.
  • Fungus.
  • Allergies.
  • Conditions and medications that cause a reduced immune system.


Symptoms of keratitis can include:

  • Redness.
  • Pain.
  • Excessive tearing.
  • Blurred vision.
  • Light sensitivity.


Keratitis is best diagnosed by a doctor of optometry, who can provide treatment options. Necessary testing might include:

  • Patient history to determine symptoms and the presence of any general health problems that may be contributing to the eye problem.
  • External examination of the eye using a biomicroscope to examine the cornea and to make other structures of the eye have not been affected. The doctor may apply a stain to the surface of your eye to determine the extent of the keratitis.
  • A culture or biopsy may be necessary to determine the pathogen causing the infection.


Treatment of keratitis depends on the cause of the inflammation or infection.

  • Non-infectious—for mild discomfort, artificial tears may be prescribed. In more severe cases, a bandage contact lens and anti-inflammatory eye medications may be necessary.
  • Infectious—in mild cases, eye drops (antibiotic, antiviral or antifungal, determined by the cause of the infection) are prescribed. In advanced infections, oral medications may be necessary.


If left untreated, keratitis can cause serious complications and may permanently damage your vision. Consult with your eye doctor if you experience symptoms of keratitis so that the cause of the inflammation can be determined and appropriate treatment can be initiated. To prevent keratitis, contact lens wearers should follow the wearing schedule and care regimen prescribed by their eye doctor. Do not sleep in lenses unless recommended by a doctor of optometry. Do not swim in contact lenses and always wash hands before handling lenses. If experiencing redness, pain or blurry vision, remove the contact lenses and contact your doctor of optometry.

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