Colobitol eye drops belong to the quinolone antibacterial agents, the main side effects are: 1. Allergic reactions and irritation of the ocular surface may occur, and secondary fungal infections or the induction of drug-resistant bacteria may occur with long-term application. In case of allergic reaction, itching, erythema or rash of eyelids or periorbital skin, conjunctival edema, burning and swelling of eyelids may occur; in severe cases, anaphylactic shock, respiratory distress, decreased blood pressure, etc., which require timely discontinuation of the drug and anti-allergic treatment. 2. Most of them return to normal after stopping the medication.