The branches of the nasociliary nerve provide sensory innervation to structures surrounding the eye such as the cornea, eyelids, conjunctiva, ethmoid air cells and mucosa of the nasal cavity.[citation needed]
Clinical significance
Clinical assessment
Since both the short and long ciliary nerves carry the afferent limb of the corneal reflex, one can test the integrity of the nasociliary nerve (and, ultimately, the trigeminal nerve) by examining this reflex in the patient. Normally both eyes should blink when either cornea (not the conjunctiva, which is supplied by the adjacent cutaneous nerves) is irritated. If neither eye blinks, then either the ipsilateral nasociliary nerve is damaged, or the facial nerve (CN VII, which carries the efferent limb of this reflex) is bilaterally damaged. If only the contralateral eye blinks, then the ipsilateral facial nerve is damaged. If only the ipsilateral eye blinks, then the contralateral facial nerve is damaged.[citation needed]
Additional images
Nerves of the orbit. Seen from above.
Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion.
Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure.
Pathways in the ciliary ganglion.
Extrinsic eye muscle. Nerves of orbita. Deep dissection.