The ciliary nerves are small nerves that originate from the ophthalmic nerve, a branch of the trigeminal nerve. They play a crucial role in the eye's function by supplying sensory innervation to the cornea and parts of the sclera. Additionally, they carry autonomic fibers that help control the muscles responsible for adjusting the pupil size and lens shape. These nerves are part of the parasympathetic nervous system and are essential for processes like accommodation, which allows the eye to focus on near objects. Damage to the ciliary nerves can lead to vision problems and discomfort in the eye.