They are next to the base of the eyelashes, and anterior to the meibomian glands within the distal eyelid margin.
Glands of Moll empty into the adjacent lashes.
Glands of Moll and Zeis secrete sebum that keeps lashes supple.
The glands of Moll are prone to infection and blockage of its duct with sebum and cell debris.
Blockage of the gland's duct causes swelling which can manifest itself as a stye.