Frontal nerve
The frontal nerve is the largest and main branch of the ophthalmic division of the trigeminal nerve. It divides off the ophthalmic division just before entering the orbit through the superior orbital fissure outside and superolateral to the tendinous ring, where it lies between the lacrimal nerve and the superior ophthalmic vein. It then courses medially in the orbit outside the cone of muscles and between the periosteum of the orbital roof (which it supplies) and the levator palpebrae superioris muscle. It gives off a small branch to the frontal sinus before dividing into:
