They enter the eyeball to provide sensory innervation to parts of the eye, and sympathetic visceral motor innervation to the dilator pupillae muscle.

[1] The long ciliary nerves provide sensory innervation to the eyeball, including the cornea.

[citation needed] The long ciliary nerves contain post-ganglionic sympathetic fibers from the superior cervical ganglion for the dilator pupillae muscle.

[1] The sympathetic fibers to the dilator pupillae muscle mainly travel in the nasociliary nerve but there are also sympathetic fibers in the short ciliary nerves that pass through the ciliary ganglion without forming synapses.

[citation needed] This article incorporates text in the public domain from page 888 of the 20th edition of Gray's Anatomy (1918)