Along with a host of other functions, zinc is required for maintaining the health of your retina. Zinc is a trace mineral that plays the role of a helper molecule that transports vitamin A from the liver to the retina for melanin production. Melanin is a pigment that gives your iris color - black, brown, blue, green, etc. Melanin protects your eyes from sunlight (1). Zinc deficiency can cause cloudy cataracts and poor night vision. Meat and shellfish are dietary rich sources of zinc while vegetarians can get zinc from legumes such as lentils and chickpeas. Seeds and nuts are also good sources of zinc. Most eye vitamin supplements contain zinc due to these reasons.