The dosage of levofloxacin eye drops is: generally 3 times a day, 1 drop each time, according to the symptoms can be appropriately increased or decreased; for the treatment of keratitis in the acute stage every 15~30 minutes 1 drop; for serious cases in the beginning of the first 30 minutes every 5 minutes 1 drop, the condition is controlled gradually reduce the number of drops. The drug has a broader antibacterial spectrum, and its mechanism of action is to hinder the activity of DNA rotase. It has a strong antibacterial effect on gram-negative bacteria and anaerobic bacteria such as Propionibacterium and other causative organisms of ocular infectious diseases. Clinically the drug is used for the treatment of blepharitis, blepharitis, dacryocystitis, conjunctivitis, blepharitis, keratitis, as well as for sterile chemotherapy methods in the perioperative period of ophthalmology. During the use of the drug may cause shock, allergy-like symptoms, close observation should be carried out; when erythema, rash, dyspnea, decreased blood pressure, swelling of the eyelids and other symptoms are detected, the administration of the drug should be stopped immediately, and timely treatment should be carried out in the hospital. Patients with a previous history of hypersensitivity to the components of the product, ofloxacin and quinolone antibacterial agents. The drug can be used for a maximum of 4 weeks after activation; to prevent contamination of the solution, care should be taken to avoid direct contact of the front of the container with the eye when administering eye drops. If the drug is needed, it should be used under the guidance of a specialist, and should not be self-administered to avoid adverse reactions.