Area cribrosa sclerae

The Area cribrosa sclerae is a series of fine parallel canals, each of which gives access to nerve fibers of the optic nerve at the level of the disc of the optic nerve. Their caliber increases gradually from the inner to the outer surface of the sclera, to accommodate changes in nerve fiber structure and caliber. The diameter of the area cribrosa is significantly greater on the outer surface than on the inner surface.