Herpes Simplex Keratitis
Herpes keratitis is a viral infection of the eye caused by the herpes simplex virus, best known for causing cold sores. Herpes keratitis usually affects only one eye and most often occurs on the cornea—the normally clear dome that covers the front part of the eye.
The most common form of herpes keratitis involves the covering layer of cells on the cornea, called the epithelium. A typical lesion from herpes epithelial keratitis is shown below. The areas where the epithelial cells are missing stain with fluorescein, an orange-yellow dye that glows green when exposed to blue light. Infections can also occur in the deeper layers of the cornea, called the stroma. Herpes stromal keratitis typically presents with small areas of haziness in the cornea. If the infection spreads into the eye behind the cornea, it is called herpes keratouveitis.
The symptoms of herpes keratitis may include: 
- Pain
- Redness
- Blurred vision
- Tearing
- Discharge
- Sensitivity to light
If the infection is superficial, with ulcers involving only the corneal epithelium, it will usually heal without scarring. However, if it involves the deeper layers of the cornea, it may lead to scarring of the cornea, loss of vision, and sometimes even blindness. Left untreated, herpes keratitis can severely damage your eye.
Herpes keratitis is usually treated with antiviral medications, either in eyedrop or pill form. In some special cases, topical steroids may be
Once herpes keratitis resolves, it is always possible for it to recur, although this can be quite variable between patients. If recurrent disease occurs, prophylactic oral antivirals are often used to prevent prevent future recurrences.