n :  either of two veins that pass from the orbit:  a  :  one that begins at the inner angle of the orbit and passes through its superior part and through the superior orbital fissure to empty into the cavernous sinus - called also superior ophthalmic vein   b  :  one that drains a venous network in the floor and medial wall of the orbit and passes posteriorly dividing into two parts of which one passes through the inferior orbital fissure to join the pterygoid plexus of veins and the other passes through the superior orbital fissure and empties into the cavernous sinus - called also inferior ophthalmic vein  .
 
 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2024.