The ophthalmic nerve [V1] exits the skull through the superior orbital fissure and enters the orbit. Its branches (Fig. 8.64) that innervate the face include: the supra-orbital and supratrochlear nerves, which leave the orbit superiorly and innervate the upper eyelid, forehead, and scalp; the infratrochlear nerve, which exits the orbit in the medial angle to innervate the medial half of the upper eyelid, the skin in the area of the medial angle, and the side of the nose; the lacrimal nerve, which exits the orbit in the lateral angle to innervate the lateral half of the upper eyelid and the skin in the area of the lateral angle; and the external nasal nerve, which supplies the anterior part of the nose (Fig. 8.65).