Chalazions ("small pimples" in Greek) are cysts, or fluid-filled sacs, on the edge of the eyelid. Small glands in the eyelids called meibomian glands normally secrete a thick, fatty fluid called sebum into the hair follicles of the eyelashes. When these glands become chronically inflamed, chalazions – also called meibomian cysts – form.
A doctor usually treats chalazions by prescribing antibiotic eye drops and warm compresses. He or she may also drain a firm cyst by pressing on it to release the sebum trapped inside or inject a steroid medication to decrease inflammation.