Bones of the left orbit.  The orbital rim is formed superiorly by the frontal bone, laterally by the zygomatic bone, inferiorly by the maxilla, and medially by portions of the frontal and maxillary bones. Openings into the orbit include the optic canal, an opening in the lesser wing of the sphenoid, the superior orbital fissure, a space between the lesser and greater wings of sphenoid, and the inferior orbital fissure, a space between the greater wing of sphenoid and the orbital portion of the maxilla. The supraorbital foramen or notch, as represented in this specimen, is located along the superior border of the orbit at the junction between its medial one-third and lateral two-thirds. The infraorbital foramen is the opening of the infraorbital canal several millimeters inferior to the lower border of the orbit. The supraorbital and infraorbital foramina follow along a vertical line through them. The bones of the medial wall of the orbit are very thin and include the lacrimal bone and orbital plate of the ethmoid bone (lamina papyracea). Sites of dehiscence here have exposed ethmoid air cells. The lacrimal fossa is a depression in the lacrimal bone and contains the lacrimal sac. It is bounded anteriorly by the anterior lacrimal crest of the maxilla and posteriorly by the posterior lacrimal crest of the lacrimal bone. (Image courtesy of AL Rhoton, Jr.)