As blood glucose levels
increase, glucose also
increases within the aqueous humor, glucose readily diffuses across the lens capsule, an aldose reductase pathway converts glucose to sorbitol, sorbitol accumulates within the lens as it can not diffuse through lens cell membranes, the osmotic gradient
increases, water enters the lens and irreversibly changes the lens structure via lens fiber swelling and rupture,
vacuole formation, and clinically evident cataract.