Cataract is one of the main causes of blindness in the current world, pathological basis of cataract is abnormal metabolism of lens as well as lenticular opacification. So far,it has been found that changes of osmotic pressure play an important role in the phase of lens’ metabolism, which influence polyol pathway, aquaporin, and gap junction proteins in the lens epithelial cell. Eventually these changes can affect lens’ metabolism and lead to the formation of cataract. This study makes statesment in the mechanism of function and effectiveness of osmotic pressure on lens’ metabolism.