Frontal boneIt forms the roof of the orbit. It also forms the upper rim of the opening.
Zygomatic boneIt forms the outer wall of the orbit. It also forms the outer part of the floor.
MaxillaIt forms most of the inner part of the orbit's floor.
Lacrimal boneA small, rectangular bone at the front of the inner wall. Tears drain past it toward the nose.
Ethmoid boneWith the lacrimal bone it forms much of the orbit's inner wall.
Sphenoid boneIt forms the back of the orbit. The optic canal and the superior orbital fissure are openings in it.
Palatine boneIt adds a small part to the orbit's floor beside the maxilla.
Openings 4
Optic canalThe opening at the apex of the orbit. The optic nerve passes through it on its way from the eye to the brain.
Superior orbital fissureA long, irregular opening on the outer side of the optic canal. The nerves to the muscles that move the eye pass through it.
Supraorbital foramenA small opening near the middle of the upper rim. A nerve to the skin of the forehead passes through it.
Infraorbital foramenAn opening in the maxilla below the orbit. A nerve to the skin of the face below the eye comes out of it.
How this list was compiled: Every name and detail checked on 2026-09-30 against OpenStax Anatomy and Physiology 2e, section 7.2 The Skull (the orbit: seven bones and the walls they form, optic canal, superior orbital fissure; supraorbital and infraorbital foramina; lacrimal bone), https://openstax.org/books/anatomy-and-physiology-2e/pages/7-2-the-skull, and against Wikipedia, Orbit (anatomy), text only. Licence: own work
The drawing: Drawn for this site on 2026-10-05. The proportions of the opening, the places where the sutures cross the rim and the width of the bone round it were checked against a public domain plate, and the outline of the small skull follows points read off it: Henry Gray, Anatomy of the Human Body (20th US edition, 1918; Wikimedia Commons, public domain), fig. 190 'The skull from the front' (https://commons.wikimedia.org/wiki/File:Gray190.png). Licence: own drawing; skull outline after a public domain plate
How it works
Seven bones meet in the orbit, the socket that holds the eye. The drawing looks into the right orbit from the front, nose to the right, and holds the bony features of the orbit, with four openings asked after the bones.
Read the full guide
Bones first, then openings
Numbers 1 to 3 are the big bones round the opening: the forehead above, the cheekbone at the outer side, the upper jaw below. Numbers 4 to 7 are inside: two on the inner wall, one at the back and a small one on the floor. Numbers 8 to 11 are openings: two at the back of the socket, one above the rim and one below it.
The inner wall is on the side of the nose; the outer wall is on the side of the cheek.
The optic canal is round; the superior orbital fissure beside it is a long slit.
Questions and answers
What are the 7 bones of the orbit?
The frontal, zygomatic, maxilla, lacrimal, ethmoid, sphenoid and palatine bones. The first three show round the opening; the other four lie inside the socket.
Which bones form the walls of the orbit?
The frontal bone forms the roof. The zygomatic bone forms the outer wall and outer floor. The maxilla, with the small palatine bone, forms the inner floor. The ethmoid and lacrimal bones make up much of the inner wall; the sphenoid forms the back.
What passes through the optic canal?
The optic nerve, on its way from the retina of the eye to the brain. The canal opens at the apex, the narrow back end of the orbit.
What is the superior orbital fissure?
A long, irregular opening at the back of the orbit, on the outer side of the optic canal. The nerves to the muscles that move the eye pass through it, with sensory nerves.