Long ciliary nerves

The long ciliary nerves are two-three sensory nerves that arise from the nasociliary nerve (itself a branch of the ophthalmic branch (CN V₁) of the trigeminal nerve (CN V)). They pass forward within the orbit, passing toward the eyeball alongside the optic nerve (CN II). They enter the eyeball to provide sensory innervation to the cornea, iris, and ciliary body. They also provide sympathetic visceral motor innervation to the dilator pupillae muscle, which is responsible for dilation of the pupil. The long ciliary nerves are clinically relevant in conditions affecting corneal sensitivity, pupillary responses, and surgical procedures involving the eye.