The postganglionic sympathetic fibers destined for the orbit travel with the ophthalmic artery. Once in the orbit the fibers are distributed to the eyeball either by: passing through the ciliary ganglion, without synapsing, and joining the short ciliary nerves, which pass from the ganglion to the eyeball; or passing through long ciliary nerves to reach the eyeball.
In the eyeball postganglionic sympathetic fibers innervate the dilator pupillae muscle.