Optic Chiasm

Optic Chiasm

Sumit Karia MD

The Common Vein Copyright 2010


Size  The mean width is 14.0 mm.  The mean area is 43 mm2.

Shape  Quadrilateral shape


Located behind the genum of the corpus callosum. Its inferior face rests over the hypophysis. Its superior face is connected to the base of the cerebrum thorough a very thin lamina consisting of gray matter, the lamina terminalis. The two anterior angles originate the optic nerves; the two posterior angles give rise to the optic tracts. These head posteriorly, surround the crus cerebri, later dividing in 2, which terminate in the internal and external geniculate bodies of the thalamus.


The optic chiasm is made of white substance.


Being formed by a partial crossing of the nerve fibers from the optic nerves, it allows stereoscopic vision, also known as a field of depth.