Bacterial keratitis is a common ophthalmic disease, but one would not expect that it can actually be caused by a variety of bacteria, and the symptomatic features of the infection can vary from one bacteria to another. 1. Gram-positive coccus infection The cornea appears as a round or elliptical focal abscess lesion with a distinct gray-white stromal infiltrate at the border. Staphylococci, both coagulase-negative and positive genera, can lead to severe stromal abscesses and corneal perforation. Pneumococcal-induced keratitis (creeping corneal ulcer) presents as an oval, central stromal ulcer with creeping margins and deeper, often with pus accumulation in the anterior chamber. 2, gram-negative bacterial infection manifests as rapidly developing corneal liquefaction necrosis. The infection caused by Pseudomonas aeruginosa is characteristic. This type of ulcer is most often caused after corneal foreign body removal, or by wearing contact lenses, or by the use of contaminated sodium fluorescein or other eye drops. Patients have significant ocular pain, severe ciliary congestion or mixed congestion, and even bulbar conjunctival edema. Due to the production of proteolytic enzymes by P. aeruginosa, the cornea shows rapidly expanding infiltration and mucous necrosis, ulcerated foci of infiltration and slightly yellowish-green discharge, and severe pus accumulation in the anterior chamber. If the infection is not controlled, it can lead to corneal necrosis and perforation, eye content prolapse or total ophthalmoplegia 3, gonococcal infection Most of the newborns delivered through the birth canal. The affected eye has photophobia, lacrimation, pain, visual impairment, and blepharospasm. There is a high degree of eyelid edema, bulbar conjunctival edema and copious purulent discharge, ciliary or mixed congestion with corneal epithelial defects, corneal stromal infiltration and ulceration. The anterior chamber may have varying degrees of extreme pus. It often leads to corneal perforation. To sum up, these three bacteria are infections caused by direct hand contact with the lesion. It is worth drawing our attention to pay attention to personal hygiene when touching the wound to reduce unnecessary bacterial infections.