Erythromycin ophthalmic ointment belongs to the commonly used antibiotic ophthalmic ointment, which is usually applied continuously for no more than 1 month, and the specific use time is related to the patient’s condition. Erythromycin ophthalmic ointment belongs to broad-spectrum antibiotic eye ointment, which is a macrolide antibiotic, and is widely used in bacterial infectious diseases of the eye, such as bacterial conjunctivitis and bacterial keratitis. Patients who have bacterial infectious diseases of the eye and need to be treated with erythromycin ophthalmic ointment are usually not recommended to apply it continuously for more than one month. Because long time using the same antibiotic eye ointment for treatment, it is easy to cause the patient to bacterial drug resistance, if the treatment does not get better, it should be changed to other antibiotics within a month, but the specific use of time is related to the patient’s condition. It is recommended that patients use erythromycin ophthalmic ointment as prescribed by the doctor to assess their condition and follow the doctor’s instructions.