Keratitis can be treated with erythromycin eye ointment, but it should be used at night, not during the day. Keratitis involves inflammation of the cornea, and can be classified into bacterial keratitis, viral keratitis, fungal keratitis, corneal ulcers, and corneal perforation. If not treated promptly, it can severely affect vision. After the onset of keratitis, it is important to properly use eye drops and ointment for treatment. Regular rest and a light diet should be maintained. Avoid spicy and irritating foods, do not stay up late, use your eyes correctly, do not rub your eyes with dirty hands, have regular check-ups, and monitor your vision.