Various pathogenic factors put the conjunctiva in a damaged state, causing lesions that lead to edema called conjunctival edema; if not properly taken care of, it can cause keratitis and corneal ulcers in mild cases, or infection or even blindness in severe cases. What is the diagnosis of conjunctival edema and corneal ulcers? If conjunctival edema is not properly cared for, it can cause keratitis and corneal ulcers in mild cases, or infection and even blindness in severe cases. In the early stage of corneal ulcer, the eye has obvious irritation symptoms, photophobia, tearing, eye pain, grayish white dots or lamellar infiltration on the cornea; in severe cases, the above symptoms become more obvious, unable to open the eye, eye pain is unbearable, and vision is reduced. The conjunctiva is purplish-red and congested, and the closer it is to the cornea, the more serious it is, and grayish-white necrotic tissue is seen on the surface of the cornea, forming ulcers. If the bacteria are highly virulent, combined with chronic dacryocystitis or systemic resistance is reduced, the ulcer spreads to the surrounding or deeper layers, forming pus in the anterior chamber and even causing corneal perforation, causing serious damage to vision. Pseudomonas aeruginosa corneal ulcers often cause corneal perforation within 1-2 days, with very serious consequences. Mycobacterial corneal ulcer, on the other hand, starts with mild symptoms, irregular ulcer surface, grayish-white, and pus often accumulates in the anterior chamber.