Ophthalmic nerve (V1): the upper division of the trigeminal
Quick facts
- Origin
- First division of the trigeminal nerve (V1), leaves the skull through the superior orbital fissure.
- Type
- Purely sensory.
- Branches
- Frontal (supraorbital and supratrochlear), lacrimal and nasociliary.
- Territory
- Forehead, anterior scalp, upper eyelid, cornea and nasal dorsum.
The ophthalmic nerve, or V1, is the first and highest division of the trigeminal nerve. It is purely sensory and supplies the skin of the forehead, anterior scalp, upper eyelid and nasal dorsum, as well as the cornea. It controls no muscle: forehead movement comes from the facial nerve.
What are the branches?
V1 enters the orbit through the superior orbital fissure and divides into three.
| Branch | Terminations | Territory |
|---|---|---|
| Frontal | Supraorbital and supratrochlear | Forehead, upper eyelid, anterior scalp |
| Lacrimal | Branches to the lacrimal gland | Lateral part of the upper eyelid and lacrimal gland |
| Nasociliary | Infratrochlear, external nasal, ethmoidal and ciliary | Medial canthus, nasal dorsum and tip, cornea |
Why does V1 matter in practice?
The V1 territory is, to a large extent, the upper third of the face, where the glabella, the forehead lines and the nasal root are concentrated. This is the same territory supplied by branches of the ophthalmic artery. The overlap between a sensory nerve and high-risk vessels makes V1 a reasoning tool:
- Pain as a signal: intense pain in the forehead, nasal root or around the eye after a procedure is a symptom to take seriously.
- Expected numbness: after local anesthesia or a supraorbital block, the forehead and upper eyelid may be numb for a few hours.
- Herpes zoster ophthalmicus: lesions on the forehead, eyelid or tip of the nose indicate involvement of V1. The assessment is medical and urgent, and it is not the time for an aesthetic procedure.
- Headache: part of frontal headache depends on V1, and a history of chronic headache should be in the medical history before toxin in the upper third.
How to tell V1, V2 and V3 apart?
A simple way to remember is by the size of the territory: V1 covers the forehead and nose, V2 covers the cheek and upper lip, and V3 covers the chin and lower lip. If you draw a horizontal line through the eye and another through the mouth, the face splits into three bands, each with one nerve.
Also called: ophthalmic division of the trigeminal, V1, nervus ophthalmicus.
Frequently asked questions
Does V1 control forehead movement?
No. V1 only carries sensation. What moves the forehead is the facial nerve, which controls the frontalis muscle.
Why is the V1 territory considered high-risk?
Because vessels such as the supratrochlear, supraorbital and dorsal nasal arteries communicate with the ophthalmic artery. Vascular complications there can reach the eye.