Muscle · Head

Inferior rectus

Musculus rectus inferior

The downward-pulling member of the four straight eye muscles, running forward along the floor of the socket. Like the other three recti it starts from a shared fibrous ring around the optic nerve at the very back of the orbit and runs forward to attach to the white of the eye in front of its widest point — an arrangement that makes the four of them a sling the eye sits inside. Because the orbit points slightly outward while the eye points straight ahead, this muscle does not pull purely downward: it also draws the eye toward the nose. A sheath from its lower surface reaches the lower eyelid, so the lid follows the eye down when you look at the floor.