Chalazion

<B>Chalazion:</B> A cyst of the little glands in the eyelids that make a lubricant which they discharge through tiny openings in the edges of the lids.

The lubricant is a fatty substance called sebum characteristic of sebaceous glands.</P> These glands are called the meibomian glands.

Inflammation of them is termed meibomianitis or, alternatively, meibomitis.

Chronic inflammation of the meibomian glands leads to meibomian cysts or chalazions.</P> The word 'chalazion' is Greek for small pimple (and little hail).

Like a pimple, a chalazion is an inflamed swelling.

But instead of being on the skin, a chalazion is in the margin of the eyelid.</P> The meibomian glands are named for a 17th-century German anatomist Heinrich Meibom (who must have had good eyes to see these minute structures).

They are also known as the palpebral glands, tarsal glands, or tarsoconjunctival glands.