Which nerve provides the corneal sensation and is a branch of the ophthalmic division?

• A. Nasociliary
• B. Frontal
• C. Lacrimal
• D. Zygomatic

Answer: (A)

Corneal sensation is carried by sensory fibers that travel with nerves arising from the ophthalmic division (V1). The nasociliary nerve is the branch of V1 that supplies the cornea, delivering its sensory fibers via its branches to the corneal surface (including the long ciliary nerves). The frontal nerve and lacrimal nerve are also branches of V1, but they innervate other structures (forehead/eyelids and lacrimal gland/conjunctiva, respectively) and not the cornea. The zygomatic nerve belongs to the maxillary division (V2), not V1. So the nerve providing corneal sensation from the ophthalmic division is the nasociliary nerve.