The inferior oblique is one of the external muscles of the eye within the orbit. It is a thin muscle that originates from the orbital surface of the maxilla. It passes posterolaterally. Along this path, it passes inferiorly to the inferior rectus muscle of the orbit.
It inserts into the sclera of the eye on its lateral aspect. At this point the insertion is posterior to the midline of the eye.
Inferior oblique is innervated by the inferior division of the oculomotor nerve (C.N. III).
Its actions on the eye are to:
- elevate it when adducted to the midline
- extort it when abducted
- assist in abduction
- protrude it within the orbit