What is the name of the sebaceous gland located on the posterior margin of each eyelid?

The sebaceous gland located on the posterior margin of each eyelid is known as the Meibomian gland. These glands play a critical role in maintaining eye health by secreting an oily substance called meibum, which forms part of the tear film. This oily layer helps to prevent the evaporation of tears, ensuring that the surface of the eye remains lubricated. The proper functioning of Meibomian glands is essential for preventing dry eye syndrome and maintaining overall ocular comfort.

Other terms such as chalazion gland or apocrine gland do not describe sebaceous glands related to the eyelid structure. A chalazion typically refers to a cyst that forms due to the blockage of a Meibomian gland, while apocrine glands are a different type of gland that are found in other areas of the body, particularly in the armpits and groins, and are not related to the eyelids.