Anterior eye: sagittal section (Latin)

Sagittal section of the anterior structures of the eyeball, the conjunctiva and the palpebrae. Directly adjacent to the cornea is the tunica conjunctiva bulbi oculi, a mucous membrane which lines the anterior surface of the eyeball and continues along the inner surface of the palpebrae as the tunica conjunctiva palpebrarum. Also depicted in the image are the numerous layers composing the eyelid: outermost the skin and cilia, followed by a layer of subcutaneous tissue (the tela subcutanea), skeletal muscle, the tarsus and innermost, the palpebral conjunctiva. The skeletal muscle within the eyelid is mainly fibres of the pars palpebralis musculi orbicularis oculi, which surrounds the eye and acts as a type of sphincter, as it closes the eyes upon contraction. The tarsus is a plate of dense connective tissue, responsible for the crescent-shaped form of the eyelid, conforming to the convex anterior surface of the eyeball.