Konya (Turkish pronunciation: [Ëkon.ja]; Greek: á¼°ÎºÏÎ½Î¹Î¿Î½ IkÃ³nion, Latin: Iconium) is a major city in the Central Anatolia Region of Turkey. It is the seventh-most-populous city in Turkey. As of 2016[update], Konya has a population of over 2.1 million.
Vitamin A is needed by the retina of the eye in the form of retinal, which combines with protein opsin to form rhodopsin, the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision. Retinol, the form of vitamin A absorbed when eating animal food sources, is a yellow, fat-soluble substance. 2  Since the pure alcohol form is unstable, the vitamin is found in tissues in a form of retinyl ester. 3  It is also commercially produced and administered as esters such as retinyl acetate or palmitate.
Researchers have found that certain nutrients, such as lutein/zeaxanthin, vitamin C, vitamin E, and zinc, can reduce the risk of certain eye diseases, including macular degeneration and cataracts. For more information on the importance of good nutrition and eye health, please see the diet and nutrition section.