By Enyeribe Ejiogu

Good nutrition is clearly very important for keeping the eyes healthy and functioning well throughout a person’s lifetime. Research studies have shown that antioxidants and other important nutrients may reduce the risk of cataracts and macular degeneration, which causes glaucoma and ultimately leads to blindness. Specific antioxidants can have additional benefits as well. For example, vitamin A protects against blindness, and vitamin C may play a role in preventing or alleviating glaucoma.
Omega-3 essential fatty acids appear to help the eye in a variety of ways, from alleviating symptoms of dry eye syndrome to guarding against macular damage.
Benefits of vitamins and micronutrients for the eyes
The following vitamins, minerals and other nutrients have been shown to be essential for good vision and may protect the eyes from the conditions and diseases that rob one of sight.
Incorporating the following foods in your diet will help you get the recommended dietary allowance (RDA) of these important eye nutrients. Established by the Institute of Medicine (National Academy of Sciences), the RDA is the average daily dietary intake level of a nutrient sufficient to meet the requirements of nearly all healthy individuals in a specific life stage and gender group.
While the RDA is a useful reference, some eye care practitioners recommend higher daily intakes of certain nutrients for people at risk for eye problems.
(In the following list, mg means milligram; mcg = microgram (1/1000 of a mg) and IU = International Unit.)
Beta-carotene
Beta-carotene has been established to be very beneficial in enhancing the health of eyes. When taken in combination with zinc and vitamins C and E, beta-carotene may reduce the progression of macular degeneration. The major sources of beta-carotene are carrots, sweet potatoes, spinach, kale, butternut squash.
While the consumption of a number of micronutrients have a recommended dietary average (RDA), there in no RDA for beta-carotene. Most over-the-counter supplements contain about 5,000 to 25,000 IU of beta-carotene.
Bioflavonoids (Flavonoids)
Bioflavonoids are believed to provide protection against cataracts and macular degeneration. Bioflavonoids are important antioxidants that help keep the eyes and body healthy. Foods high in vitamin C, such as citrus fruits and many vegetables, are also excellent sources of bioflavonoids.
Bioflavonoids have been used in alternative medicine as an aid to enhance the action of vitamin C, to support blood circulation, viruses, or arthritis and other inflammatory conditions, especially when they occur in the eyes.
Examples of citrus fruits that contain a lot of bioflavonoids and vitamin C include lemon and lime, as well as peaches, nectarines and other fruits. Again the green vegetable, broccoli, has a lot of vitamin C, as well as some other essential vitamins. Other sources of bioflavonoids are tea, red wine, bilberries, blueberries, cherries, legumes and soy products. Taking these items regularly will arm the eyes to function properly and enhance the health of the internal structures of the eyes. There is no recommended dietary average consumption.
Lutein and Zeaxanthin
Two very important eye nutrients that may reduce your risk for macular degeneration and cataracts have names you may not be familiar with: lutein and zeaxanthin.
Lutein and zeaxanthin are two types of carotenoids, which are yellow to red pigments found in many vegetables and other plants. Though lutein is considered a yellow pigment, in high concentrations it appears orange-red.
Cooked spinach is one of the best natural food sources of lutein and zeaxanthin.
In nature, lutein and zeaxanthin appear to absorb excess light energy to prevent damage to plants from too much sunlight, especially from high-energy light rays called blue light.
In addition to being found in many green leafy plants and colorful fruits and vegetables, lutein and zeaxanthin are found in high concentrations in the macula of the human eye, giving the macula its yellowish color. In fact, the macula also is called the “macula lutea” in medicine. It derives the from the Latin ‘macula’ meaning “spot,” and ‘lutea’ meaning “yellow.”
Recent research has discovered a third carotenoid in the macula is called meso-zeaxanthin. This pigment is not found in food sources and appears to be created in the retina from ingested lutein.
Lutein and zeaxanthin appear to have important antioxidant functions in the body. Along with other natural antioxidants, including vitamin C, beta-carotene and vitamin E, these important pigments guard the body from damaging effects of free radicals, which are unstable molecules that can destroy cells and play a role in many diseases.
In addition to important eye and vision benefits, lutein may help protect against atherosclerosis (buildup of fatty deposits in arteries), the disease that leads to most heart attacks.
In the case of the yes particularly, lutein, zeaxanthin and meso-zeaxanthin in the macula block blue light from reaching the underlying structures in the retina, thereby reducing the risk of light-induced oxidative damage that could lead to macular degeneration (AMD).
Omega-3 fatty acids
Omega-3 fatty acids are polyunsaturated fatty acids. According to Wikipedia, there are three types of omega-3 fatty acids involved in the functioning of the human body, namely, α-linolenic acid (that is, alpha linolenic acid) which is found in plant oils), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), both commonly found in oils in marine plants. Marine algae and phytoplankton are primary sources of omega-3 fatty acids. Common sources of plant oils containing the omega-3 ALA fatty acid include walnut, edible seeds, clary sage seed oil, algal oil, flaxseed oil, Sacha Inchi oil, Echium oil, and hemp oil, while sources of animal omega-3 EPA and DHA fatty acids include fish oils, egg oil, squid oils, and krill oil.
The human body is unable to synthesize omega-3 fatty acids, but can obtain the shorter-chain omega-3 fatty acid ALA through diet and use it to form the more important long-chain omega-3 fatty acids, EPA and then from EPA, the most crucial, DHA. The ability to make the longer-chain omega-3 fatty acids from ALA may be impaired in aging. In foods exposed to air, unsaturated fatty acids are vulnerable to oxidation and rancidity.
Omega-3 fatty acids help to prevent macular degeneration (AMD) and dry eyes.
The common sources include salmon, mackerel and herring; fish oil supplements, freshly ground flaxseeds and walnuts.
Selenium
Selenium is a chemical element and a nonmetal. When combined with carotenoids and vitamins C and E, it may reduce risk of advanced AMD. Primary sources of selenium are seafoods such as shrimp, crab, salmon, halibut), Brazil nuts, enriched noodles and brown rice.
It RDA for teens is 55 mcg for teens and adults (60 mcg for women during pregnancy and 70 mcg when breast-feeding.
Vitamin A
Vitamin A is necessary for protecting the eyes against night blindness and dry eyes.
It is a fat-soluble vitamin obtainable from beef or chicken liver, eggs, butter and milk.
The RDA is 3,000 IU for men; 2,333 IU for women (2,567 IU during pregnancy and 4,333 IU when breast-feeding.
Other vitamins and minerals
Other vitamins that are vital for healthy eyes are vitamin C (oranges, strawberries, broccoli). Vitamin D obtainable from sardines, mackerel, milk; orange juice fortified with vitamin D. The best source of vitamin D is exposure to sunlight. Ultraviolet radiation from the sun stimulates production of vitamin D in human skin, and just a few minutes of exposure to sunlight each day (without sunscreen) will insure your body is producing adequate amounts of vitamin D.

Vitamin E: When combined with carotenoids and vitamin C, may reduce the risk of advanced AMD. Food sources of vitamin E are almonds, sunflower seeds and hazelnuts.
Zinc helps vitamin A to reduce the risk of night blindness; may play a role in reducing risk of advanced AMD. Zinc is obtained from oysters, beef, crab and turkey (dark meat).
In general, it’s best to obtain most nutrients through a healthy diet, including at least two servings of fish per week and plenty of colourful fruits and vegetables.
A note of caution:
If you plan to begin a regimen of eye vitamins, be sure to discuss this with your optometrist or ophthalmologist.
Taking too much of certain vision supplements can cause problems, especially if you are taking prescription medications for health problems.