Orbit (overview)

The orbits are bilateral bony cavities located in the skull, below the anterior cranial fossa and anterior to the middle cranial fossa, with openings present in the upper half of the face, on either side of the root of the nose. Each orbit contains the eyeball, the optic nerve, the extra-ocular muscles, the lacrimal apparatus, as well as adipose tissue, fascia, and nerves and vessels that supply all of these structures.


Seven bones contribute to the framework of each orbit:


Together these bones give the bony orbit the shape of a pyramid, with its wide base (the orbital rim) opening anteriorly onto the face as the orbital opening, and its apex extending in a posteromedial direction and continuing as the optic canal.

The orbital rim has four margins:

The orbit is composed of four walls: