It contains postganglionic sympathetic fibers whose cell bodies are located in the superior cervical ganglion.

Sympathetic fibers supplying the eye separate from the carotid plexus within the cavernous sinus.

Interruption of the sympathetic chain at any level (from the brainstem to the ciliary ganglion) will produce pupillary constriction (miosis) and eyelid droop (ptosis) – the classic signs of Horner's syndrome.

The levator palpebrae superioris, which is supplied by a branch of the oculomotor nerve, also elevates the upper eyelid.

However, the ciliary ganglion is not simply a relay station connecting preganglionic to postganglionic nerve fibers.

It divides into branches that innervate the levator palpebrae superioris and four of the six extraocular muscles.

Parasympathetic fibers initially run in the inferior division of the oculomotor nerve.

These nerves enter the posterior aspect of the eyeball to supply the sphincter pupillae and ciliaris muscles.

The ciliaris muscle changes the shape of the lens, allowing the eye to focus on nearby objects (accommodation).