Inflammation or irritation of the cornea due to infection, dryness, or injury and characterized by pain, foreign body sensation, photophobia, blurred vision, red eye, and teary eyes. Depending on the type, it can progress rapidly, resulting in scarring, endophthalmitis, perforation, and blindness. Types include dendritic keratitis, keratitis sicca, neuroparalytic keratitis, rosacea keratitis, and interstitial keratitis.