This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Galactose and fructose metabolism, Subject name: Biochemistry
Snow flake cataract is produced because of : 
Select and explain. 
A. Aldose reductase, B. Galactose reductase, C. Fructose dehydrogenase, D. Alcohol dehydrogenase
A: Aldose reductase
Answer: A: Aldose reductase 
Explanation: In Diabetics, Excess Glucose freely enters the cells of eye which are highly permeable to glucose. Here glucose is reduced by Aldose Reductase enzyme to produce Sorbitol/ Polyol. Sorbitol is hygroscopic in nature and absorbs water. Swelling due to excess sorbitol in the lens will ultimate leads to Snowflake cataract.