Ophthalmic nerve (V1)

Nervus ophthalmicus

NervousNervesHeadLeft and right

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What it is
The upper, purely sensory division of the trigeminal nerve. It passes through the superior orbital fissure and splits into frontal, lacrimal and nasociliary nerves; the frontal nerve runs along the orbit roof and emerges at the supraorbital notch onto the forehead.
Function
Sensation from the forehead and scalp back to the vertex, upper eyelid, cornea and conjunctiva, bridge of the nose and the frontal and ethmoid sinuses.
Size
About 2.5 mm thick, 2.5 cm to the fissure
Clinical note
The corneal reflex tests V1 (the blink is via the facial nerve). Shingles in V1 (herpes zoster ophthalmicus) threatens the cornea; a lesion on the nose tip warns of eye involvement.

Part of Trigeminal ganglion

Nearby nervous structures Abducens nerve (CN VI), Amygdala, Frontal lobe, Globus pallidus, Maxillary nerve (V2), Oculomotor nerve (CN III), Olfactory nerve (CN I), Olfactory tract root (CN I), Optic nerve (CN II), intracranial part, Putamen