This is the maximum stage of corneal oedema.
It is a pathological condition in which small vesicles, or bullae, are formed in the cornea due to endothelial dysfunction. In a healthy cornea, endothelial cells keep the tissue from excess fluid absorption, pumping it back into the aqueous humour. When affected by some reason, such as Fuchs' dystrophy or a trauma during cataract removal, endothelial cells suffer mortality or damage. The corneal endothelial cells normally do not undergo mitotic cell division, and cell loss results in permanent loss of function.