The limbus:

The corneo-scleral junction , limbus is a region between 1mm and 2mm long between the sclera and cornea.

Schlemm ’s canal or the scleral venous sinus encircle the limbal region. Generally oval in section, it is likely to divide in to several canals which interconnect. It lies within the scleral tissues, internally coverd with a solitary layer of endothelium; the latter prevents direct connection between the anterior chamber and schlemm’ s canal.

Schlemm’ s  canal drains into the intrascleral plexus within the sclera, via 25 to 30 collector canals, then from here into anterior ciliary veins. Some of these outlets ( the aqueous veins) penetrate the sclera more directly but also empty into the anterior ciliary veins. Such aqueous veins are normally virtually colorless, containing only aqueous.