Corneal ulceration refers to a breakdown in the surface of the cornea (clear membrane that encapsulates the front of the eye). Trauma to the eye is the most common cause of ulceration to the cornea. Other causes include: viral infections (e.g.: Herpesvirus in cats), bacterial infections, abnormal eyelash growth, allergies, and medications. Pets with a corneal ulcer tear excessively, squint, and blink their eyelids often. Diagnosis of a corneal ulcer requires a special stain to highlight the ulcer and determine the extent of its border. Corneal ulcers are treated with antibiotic drops; some pets may also need drops to decrease the inflammation within the eye. Severe ulcerations require surgery to repair the defect and prevent corneal rupture. Corneal ulcerations must be monitored closely with frequent recheck examinations to ensure resolution. Part of any therapy for corneal ulceration must also address the primary cause of the ulcer to prevent recurrence.