Herpetic keratitis is a herpes simplex virus infection of the eye. There are two types of herpes viruses, herpes simplex 1 (HS1) and 2 (HS2). HS2 herpetic keratitis is more rare since HS2 is sexually transmitted. HS1, however can spread to the eye by touching an infected mouth sore and then touching the eye. Symptoms of herpetic keratitis include redness, photophobia (light sensitivity), blurred vision, tearing, and pain. Herpetic keratitis is also the most common form of infectious blindness in the world. Most infections, however, are healed on their own within three weeks. Oral and topical antiviral therapies are also effective treatments for herpetic keratitis.