In general, night blindness, whose symptoms are that people are unable to see things clearly when they are in dark at night or in environments with dim light. It is usually caused by the lack of vitamin A, malnutrition or pathological changes of the retina rhabdocyte cells. And some are inborn hereditary night blindness. As for cataracts, this kind of eye disease is caused by lens phacoscotasmus because of aging, inheritance, metabolic disturbance, trauma, radiation, poisoning, topo-malnutrition, and so on and so forth, which lead to the damage of lens phacoscotasmus peplos or degeneration of the proteins in the phacoscotasmus, making lens opacity. The main measure to treat the cataracts is to take a surgery to remove the bad lens phacoscotasmus, and sometimes people can use artificial phacoscotasmus to take place of the old one.