One of the best things anyone can do for themselves is to eat foods that support health. Any doctor who is worth her salt will tell you how to optimize your diet for your particular health needs. The eyes in particular are sensitive to metabolic disease and systemic inflammation, which can be caused by eating bad (trans) fats, having high blood sugar, and not consuming enough antioxidants.
All antioxidants, including the ones you get from eating berries and bright colored vegetables, are fair game. The more the merrier, in fact, because they seem to have synergistic effects. The specific antioxidants that are protective pigments in the eye are lutein and zeaxanthin. You can buy supplements that have these things in them, but you don't have to. The best way to get these may be by eating good food. Dark leafy greens are an excellent source of these and of vitamin A. Spinach salads, kale, turnip greens and collards are best, but anything green probably has some of it in there. If you're not wild about greens, maybe you can find some other way to get a daily dose of them, such as putting them in casseroles and blending them up in a yummy fruit smoothie. Other vegetable sources of are broccoli, pumpkin, brussel sprouts, and sweet yellow corn. Anything that is brightly orange or yellow-colored has a chance of containing some.
One of my favorite sources is egg yolks. Each egg yolk contains approximately 210 micrograms. You'll notice, if you're an egg-eater, that egg yolks are not all the same color. The ones you want are the brightest, orangiest ones you can find. Usually organic eggs have better color, but they are so expensive that many people balk. You can scope out the best source of eggs from your grocery store by noting the yolk color each time you break some open. If you have two different brands, break open one from each dozen and compare. When you go shopping again, bias your buying toward the brighter yolks. They're good for your eyes. Eggs also happen to contain B vitamins and choline which are good for your brain and liver and most everything else. And in case you hadn't heard yet, eggs do not drive up your cholesterol, so if you stopped eating them for that reason, you can start up again now.
Another dietary addition that is great for the eyes is Brazil nuts. They contain just enough selenium that eating 2/day will keep you replete for the nutrient. If these nuts aren't your favorite, try chopping them up and mix them into your breakfast oatmeal. You won't even notice them, but they will help your eyes and support many other body systems as well.
Aging gentlemen need to be aware that taking a lot of zinc, without also consuming plenty of antioxidants, could actually cause macular degeneration. Zinc is great for the guys because it helps prevent BPH, so lots of men take it later in life. Make sure you're also eating colorful fruits and berries to prevent this possible negative effect!
One last suggestion that might help you keep your vision longer is to always protect your eyes from the sun. This means buying quality sunglasses and using them when you're in bright sun. Never stare directly at the sun (just like your momma said), and use hats to help protect your eyes when you're out for a long time.