How long the eye drops are good for depends on the degree of the disease and the duration of the disease. For short-term bacterial conjunctivitis, antibacterial drugs, such as levofloxacin drops, may be used for 3-4 days, the symptoms will be significantly relieved or even disappeared, and then consolidated for 2-3 days can be discontinued. If seasonal allergies or perennial allergies, you need to use anti-allergy drops, commonly used Olopatadine drops, these drops according to the seasonal and perennial, may be used throughout the spring or fall, some people are allergic to perennial allergies may need to be used throughout the year. Therefore, the duration and number of eye drops should be decided according to the condition and the duration of the disease.