Ophthalmic a

The ophthalmic a. is the first branch of the internal carotid a.  It branches off the internal carotid either within the cavernous sinus or just after the internal carotid exits the cavernous sinus, and travels into the orbit through the optic canal with the optic nerve.  The central retinal a. is a branch of the ophthalmic a.  The opththalmic a. is the sole blood supply to the orbit.

Superior view of the left orbit to show the branches of the ophthalmic a.