This illustration is an adaptation of a drawing from Wolff’s “Anatomy of the Eye and Orbit” which shows a horizontal section of the eyelid.

The front half (anterior lamella) of the eyelid consists mainly of skin and muscle, whereas the back half of the eyelid (posterior lamella) is composed of the meibomian glands embedded in a firm tissue known as the tarsal plate. Meibomian glands open out onto orifices on the eyelid margin behind the the eyelashes.