Eye anesthetics have surface anesthetics, local infiltration anesthetics, usually these two surface anesthetics, routinely used is Alkain, drops used in the eye will be able to play the role of surface anesthesia. The effect of anesthesia is in about half an hour, after half an hour will feel the pain. The anesthetics used for local infiltration anesthesia are routinely lidocaine or procaine, which is effective for about 1-3 hours. If the appropriate amount of epinephrine is added to the procaine, the duration of anesthesia may be appropriately prolonged, possibly up to 5-6 hours. There is also the long-acting anesthetic bupivacaine, which works for 6-7 hours, after which the anesthetic effect is slowly lost.