Tissue which connects the epithelium (outer "skin" of the cornea) to the rest of the cornea.

The basement membrane is a membrane of tissue right underneath the epithelium (outer "skin" of the cornea) which helps the epithelium adhere to the next layer down (Bowman's layer or stromal tissue). Defects in this membrane resulting in poor adherence are called ABMD - in other words a loose epithelium, which is associated with chronic dry eye and recurrent corneal erosions.