Four muscles attach to the exterior surface of the eye and work together to move the eyeball in a vertical direction. Two of those muscles, the superior and inferior rectus, move the eye up and down only when the eye is rotated away from the nose. When the eye is turned toward the nose, the inferior oblique muscle is responsible for elevating the eye, while the superior oblique moves it downward. When the eye is looking directly forward, all four muscles help create vertical movement, with the rectus muscles doing half the work and the two oblique muscles performing the other half. The inferior oblique arises from a point in the middle and toward the front of the floor of the eye socket near the tear duct. It passes below the inferior rectus muscle before inserting into the back of the sclera, the outer covering of the eye. This muscle, along with three of the rectus muscles, is supplied by the oculomotor (third cranial) nerve, which is also responsible for opening the eye.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Inferior oblique