Click to identify the chalazion in the image above:

Seen here is a chalazion of the upper eyelid. A chalazion is formed when there is chronic inflammation involving the Meibomian glands when a duct gets plugged, causing a lipogranulomatous inflammation. This is an irritating, but benign, process. A recurrent chalazion should be biopsied to rule out the possibility of a sebaceous carcinoma. [Image contributed by Nick Mamalis, MD, University of Utah]