Superior oblique m

One of the 6 extra-ocular muscles, the superior oblique m. passes through a pully that re-directs its line of action.  So even though the muscle is superior to the eyeball and originates in the posterior orbit (from the annulus of Zinn, or common tendinous ring), its action is to rotate the gaze inferiorly and laterally (down and out).  The pulley the superior oblique tendon passes through is called the trochlea, and the innervation of the muscle is by the trochlear n. (CN IV).  

Superior view of the right orbit.