Marginal ulcerative keratitis, also known as corneal ulcer, is overwhelmingly an inflammatory disease caused by exogenous factors, i.e., the invasion of infectious agents into the corneal epithelial cell layer from outside. Patients often complain of decreased vision, photophobia and foreign body sensation. There is a cloudy area at the edge of the cornea due to leukocyte infiltration and ulceration, which can be stained with fluorescein green. So what are the common causes of marginal ulcerative keratitis? The following is a brief description. The common causes of marginal ulcerative keratitis ulcers: 1, improper use of contact lenses: such as wearing too long, not properly used and clean contact lenses, etc. 2, eye diseases: eyelash inversion, incomplete eyelid closure and corneal epidermal defects, etc. 3, caused by trauma: foreign objects (iron filings, sand, branches or chemicals) directly injure the cornea. 4, improper topical eye drops abuse: such as long-term steroid topical eye spotting. Marginal ulcerative keratitis and infection is currently one of the major blinding eye diseases. Due to the location of the cornea, the cornea is most vulnerable to injury and infection. It can bring a very heavy blow to people’s body and life, so for patients who have symptoms of limbal ulcerative keratitis to actively go to a professional regular hospital for systematic diagnosis and treatment to achieve early detection, early diagnosis and early treatment, only then can more effectively promote the recovery of the disease.