The autolysis of the proteins of the lens plays a definite and specific part in the process of cataract formation in certain diseases of the lens. The term autolysis may be defined as the autodigestion or hydrolysis of cellular protein by the proteolytic enzymes of the tissue. Normally, the body tissue and the lens are faintly alkaline, and the cellular proteolytic enzymes are more or less inactive, but if the tissue becomes sufficiently acid, the proteolytic enzymes begin to break down the protein. The autolysis may be initiated in the lens indirectly by a general acidosis. which may be produced through faulty metabolism in the body, or by a direct local acidosis of the lens or of the lenticular fibers. The acidosis may also arise from an inflammatory reaction of the interior of the eye, decreased permeability of the capsule and injury or death of the cells of