Hi Andrea. What you describe is a failry common condition that develops when one of the glands located on the upper or lower eyelids gets blocked, infected and subsequently inflamed. It takes a few days to increase to a size that is painful and cosmetically bothersome. Warm compresses using a washcloth soaked in regular warm water and rinsed need to be placed on the swelling keeping the eye closed. Do this twice a day 15 minutes each time for a few days. Since it is an infection you would have to start an antibiotic eye ointment like Chloramphenicol twice a day to be applied inside the eye and on the swelling as well. The pain on the eyelid as well as the inflammation may be targeted with an oral course of Ibuprofen
tablets 2 times a day. Most of these swellings, especially if small and treated early, subside on their own. However, many remain as hardened masses much smaller in size than the original but visible all the same. These would have to be removed by incision and curettage where the cheesy material within the swelling is manually expressed. Start the medication and hot fomentation as early as possible to reduce the swelling in the acute stage.