A chalazion is a chronic inflammation (not infection) of an eyelid oil gland that stimulates the formation of a surrounding cyst.

A chalazion may appear suddenly (and be confused with a sty) or slowly over many days. While a chalazion may shrink over several weeks and become painless, its core frequently remains intact.

Sooner of later, the cyst flares up again and again and may gradually deform the eyelid and distort the eyelashes.

Chalazion removal is a minor surgical procedure that takes about ten minutes.