oculomotor nerve

The oculomotor nerve (CN III) is the third cranial nerve that innervates the levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique. It also provides parasympathetic input to the sphincter pupillae, constricting the pupil, and ciliary muscle, enabling accommodation. Oculomotor nerve palsy can cause ptosis, ophthalmoplegia, and pupillary dilation. Compressive lesions require urgent evaluation to rule out life-threatening aneurysms or tumors.