Keratitis is divided into two categories: ulcerative keratitis, also known as corneal ulcer, and non-ulcerative keratitis, also known as deep keratitis. It is caused by different internal and external factors. It is an inflammation caused by corneal trauma, bacteria and viruses invading the cornea. The affected eye has a foreign body sensation, stinging or even burning sensation. The surface of the bulbar conjunctiva is mixed with congestion, accompanied by symptoms such as photophobia, tearing, visual impairment and increased secretions. The surface of the cornea is infiltrated with ulcers. Ulcerative keratitis, also known as corneal ulcer, is mostly caused by external factors, that is, inflammation caused by infectious pathogens invading the corneal epithelial cell layer from the outside.