Inferior oblique

Musculus obliquus inferior

Sensory (eye & ear)Deep musclesHeadLeft and right

View left in 3D View right in 3D

What it is

The only eye muscle that does not start at the orbit apex: it arises from the front of the orbital floor just beside the nasolacrimal canal, runs backward and outward beneath the inferior rectus and inserts on the lower-outer back quarter of the globe, near the macula.

Function

Rotates the eye outward (extorsion) and elevates and abducts it - chiefly elevation when the eye is turned in.

Size

~35 mm long; insertion ~2 mm from the macula projection.

Clinical note

Supplied by the inferior division of CN III; overaction of this muscle is common in childhood squint and is treated by weakening surgery.