Optic canal
The optic canal is a tunnel that connects the orbit with the middle cranial fossa. It is found deep within the orbit (at its apex) and is positioned on either end of the chiasmatic sulcus when viewing from the side of the middle cranial fossa. Additionally, the optic canal is found medial to the superior orbital fissure. Anteriorly, this opening is covered by the fibrous common tendinous ring (annulus of Zinn), from which the four recti extraocular muscles arise.