There are two possibilities for redness and pain in the lower eyelid: 1. Blepharitis, also called mydriasis, is an acute purulent inflammation of the eyelid glands. It is usually caused by a staphylococcal infection that invades the sebaceous or sweat glands of the lower eyelid and is characterized by redness, swelling and pain in the lower eyelid. When the eyelid is red, swollen, painful, and nodular at the onset, and the pain is obvious when pressing on the nodules, you can apply a hot compress for 10 minutes each time, three times a day. After the hot compress, apply levofloxacin eye gel oral anti-inflammatory medication to the swollen skin of the eyelid and in the conjunctival sac. 2. Acute dacryocystitis. If there is significant redness and pain in the inner part of the lower eyelid, the eye is also congested, tearing and purulent discharge may be an acute lacrimal sac. It is often an acute attack of chronic dacryocystitis that requires infection control, systemic application of antibacterial drops of anti-inflammatory eye drops, and nasal lacrimal sac anastomosis should be performed after the acute dacryocystitis is relieved.