These enzymes help chemicals in the retina convert light into electrical impulses the brain can understand. Just how much zinc we need for good health and vision is not known. People with low levels of zinc in their blood may have more eye problems than other people. Some older people have lower blood levels of zinc, either because their diets are low in zinc or because they do not absorb zinc from their food. In fact, too much zinc can interfere with the body's use of copper, another important mineral.
Vitamins probably play a role in the health of the retina.
Vitamin A is normally present in nerve cells in the retina. It is considered necessary for good vision. Some experts think that taking vitamins C and E can protect the macula from oxygen molecules that may attack it. Generally, recommended dosages of vitamins and minerals help to promote good health. However, too much vitamin A can cause a variety of problems.