Herpetic keratitis

Herpetic keratitis is a viral infection of the cornea, the transparent front surface of the eye, caused by herpes simplex virus and producing a painful, red eye. Most cases arise from the cold sore virus, which spreads through skin contact and then persists in the body. Attacks are more likely with weakened immunity and may be provoked by illness, stress, bright sunlight or eye injury, and repeat episodes are common. Usually one eye shows pain, redness, watering, light sensitivity, blurred vision and sometimes eyelid swelling or blisters. Recurrent or unresponsive infection can scar the cornea, causing sight loss and occasionally requiring a corneal transplant. An eye specialist confirms it with slit-lamp examination, fluorescein staining and testing of corneal scrapings. Treatment is antiviral eye ointment, drops or tablets, sometimes with steroid drops, and preventive antiviral tablets may be advised when infections keep returning.

Seek emergency care for sudden loss of vision, a painful red eye, or flashes and floaters that appear suddenly. See an eye specialist for gradual vision change, halos around lights, or a family history of glaucoma. Call the local emergency number for any symptom that is sudden and severe. This page is a reference for healthcare professionals and does not replace an assessment.