Chalazion is a small mass in the eyelid, caused by a blockage of a tiny oil gland in the eyelid.
A chalazion develops within the Meibomian glands of the eyelid, which are sebaceous glands that produce the tear film that lubricates the eyes. The eyelid has approximately 100 of these glands, located near the eyelashes.
A chalazion begins as diffuse swelling and tenderness, and later forms a cyst-like localized swelling.
Chalazion will often disappear without treatment within a month or so. If one continues to enlarge, it may need to be surgically removed using local anesthesia. This is usually done from underneath the eyelid to avoid a scar on the skin. Antibiotic eye drops are usually used several days before and after removal.