Ventralis oblique muscle (Vom)
The ventralis oblique muscle is a sheet-like muscle with oblique fibers that runs ventrally to the depressor palpebrae inferioris muscle. This muscle is situated on the anteroventral surface of the eyeball in the nasal pole direction. It originates from fleshy fibers of the parabasisphenoid bone, fanning out to insert as aponeurosis on the scleral cartilage. The aponeurosis of the ventralis oblique muscle passes over the dorsal surface of the aponeurosis of the ventralis rectus muscle. Its insertion site is dorsal to the insertion site of the ventralis rectus muscle on the scleral cartilage. The origin of ventralis oblique muscle is located ventral to the optic nerve and anteroventral to the origin of the dorsalis oblique muscle\RL.
Origin: Fleshly, from the parabasisphenoid bone\RL.
Insertion: Aponeurotic, on the scleral cartilage\RL.
Function: Depresses the eyeball and causes rotation (intorsion/extorsion).