Styes and chalazia are lumps in or along the edge of an eyelid. They may be painful or annoying, but they are rarely serious. Most will go away on their own without treatment. A stye is an infection that causes a tender red lump on the eyelid. Most styes occur along the edge of the eyelid. When a stye occurs inside the eyelid, it is called an internal hordeolum A chalazion (say "kuh-LAY-zee-on") is a lump in the eyelid. Chalazia (plural) may look like styes, but they are usually larger and may not be painful. Styes and chalazia may be related to blepharitis, a common problem that causes inflammation of the eyelids.