Glucose is reduced to Sorbitol (hygroscopic substance) by Aldolase reductase enzyme. Sorbitol is dehydrogenated to fructose by Sorbitol dehydrogenase enzyme. Since most cells in our body do not have Sorbitol dehydrogenase,in diabetes(when glucose level is increased) Sorbitol gets accumulated in cells, especially lens. Since Sorbitol is a hygroscopic substance, it leads to formation of cataract which is like a ❄