By Dr. Mercola
More than 70 percent of survey respondents from a National Eye Health Education Program (NEHEP) survey revealed that the loss of their eyesight would have the greatest impact on their day-to-day activities.1
Despite their prevalence and significant impact on quality of life, few are taking the necessary steps to prevent eye diseases and protect vision health at all life stages… namely, by eating a healthy diet.
Newly released data from the US Centers for Disease Control and Prevention (CDC) revealed that 87 percent of Americans are not meeting vegetable intake recommendations and 76 percent are not eating the recommended amount of fruits.3
If you want to protect your vision health, however, the time to act is now – by eating more of the healthy vision foods that follow.
The 7 Best Foods for Eye Health
1. Dark Leafy Greens
The carotenoids lutein and zeaxanthin are primarily found in green leafy vegetables, with kale and spinach topping the list of lutein-rich foods. Other healthy options include Swiss chard, collard greens, broccoli, and Brussels sprouts.
Lutein and zeaxanthin are both important nutrients for eye health,4 as both of them are found in high concentrations in your macula — the small central part of your retina responsible for detailed central vision.
More specifically, lutein is also found in your macular pigment – known for helping to protect your central vision and aid in blue light absorption — and zeaxanthin is found in your retina.
Both have been linked to a lower risk of cataracts and advanced macular degeneration. Julie Mares, professor of ophthalmology at the University of Wisconsin School of Medicine and Public Health, told Nutrition Action:5
“They’re the predominant carotenoids in both the lens and the retina, and specifically in the cone-rich area of the macula… That’s the part of the retina that’s used to see fine detail, like reading a pill bottle or newspaper…
By age 75, half of us will either have a visually significant cataract or have already had one extracted… It’s the number-one cause of poor vision among people aged 65 to 74.
There’s strong, compelling evidence for a potential protective effect of these carotenoids… They’re nutritional powerhouses… They’ve got gobs of antioxidants.”
2. Orange Pepper
According to one 1998 study in the British Journal of Ophthalmology orange pepper had the highest amount of zeaxanthin of the 33 fruits and vegetables tested.6 Zeaxanthin cannot be made by your body, so you must get it from your diet.
3. Organic Pastured Egg Yolks
Egg yolk is a source of both lutein and zeaxanthin along with healthy fat and protein, and while the total amount of carotenoids is lower than in many vegetables, they’re in a highly absorbable, nearly ideal form.
According to recent research,7 adding a couple of eggs to your salad can also increase the carotenoid absorption from the whole meal as much as nine-fold.
Keep in mind that once you heat egg yolks (or spinach) the lutein and zeaxanthin become damaged, and will not perform as well in protecting your vision; so cook your eggs as little as possible, such as poached, soft-boiled, or raw.
4. Wild-Caught Alaskan Salmon
Rich in omega-3s, the omega-3 fat DHA is concentrated in your eye's retina. It provides structural support to cell membranes that boost eye health and protect retinal function, and research suggests eating more foods rich in these fats may slow macular degeneration.
In fact, those with the highest intake of animal-based omega-3 fats have a 60 percent lower risk of advanced macular degeneration compared to those who consume the least.8
A 2009 study also found that those with the highest consumption of omega-3 fats were 30 percent less likely to progress to the advanced form of the disease over a 12-year period.9
A second study published in 2009 found those with diets high in omega-3 fats, along with vitamin C, vitamin E, zinc, lutein, and zeaxanthin, had a lower risk of macular degeneration.10 In addition to wild-caught Alaskan salmons, sardines, and anchovies are other good sources of animal-based omega-3s.
Wild-caught Alaskan salmon is a good source of astaxanthin, but you may not be able to eat enough of it to reap optimal clinical results. Astaxanthin is produced only by the microalgae Haematococcus pluvialis when its water supply dries up, forcing it to protect itself from ultraviolet radiation.
Compelling evidence suggests this potent antioxidant may be among the most important nutrients for the prevention of blindness. It's a much more powerful antioxidant than both lutein and zeaxanthin and has been found to have protective benefits against a number of eye-related problems, including:
Cataracts Age-related macular degeneration (ARMD) Cystoid macular edema Diabetic retinopathy Glaucoma Inflammatory eye diseases (i.e., retinitis, iritis, keratitis, and scleritis) Retinal arterial occlusion Venous occlusion
Astaxanthin crosses the blood-brain barrier AND the blood-retinal barrier (beta carotene and lycopene do not), which brings antioxidant and anti-inflammatory protection right to your eyes.
Dr. Mark Tso,11 now of the Wilmer Eye Institute at Johns Hopkins University, and who was my boss when I worked at the University of Illinois Eyebank in the1970s, has demonstrated that astaxanthin easily crosses into the tissues of your eye and exerts its effects safely and with more potency than any of the other carotenoids, without adverse reactions.
Depending on your individual situation, you may want to take an astaxanthin supplement. I recommend starting with 4 milligrams (mg) per day. Krill oil also contains high-quality animal-based omega-3 fat in combination with naturally occurring astaxanthin, albeit at lower levels than what you’ll get from an astaxanthin supplement.
6. Black Currants
Black currants contain some of the highest levels of anthocyanins found in nature — approximately 190-270 milligrams per 100 grams — which is far more than that found in even bilberries. They're also rich in essential fatty acids, lending added support to their anti-inflammatory properties.
Anthocyanins are flavonoids, and the health benefits of these antioxidants are extensive. As discussed in one 2004 scientific paper:12
"Anthocyanin isolates and anthocyanin-rich mixtures of bioflavonoids may provide protection from DNA cleavage, estrogenic activity (altering development of hormone-dependent disease symptoms), enzyme inhibition, boosting production of cytokines (thus regulating immune responses), anti-inflammatory activity, lipid peroxidation, decreasing capillary permeability and fragility, and membrane strengthening."
For medicinal purposes, many opt for using black currant seed oil, which is available in capsule form. But eating the whole food is always an option, especially when they're in season.
Bilberry, a close relative of the blueberry, is another nutritional powerhouse for your eyes. Its nearly black berries also contain high amounts of anthocyanins, just like the black currant (but contrary to black currant, bilberries tend to be difficult to grow and cultivate). Anthocyanin-rich bilberry extract has a protective effect on visual function during retinal inflammation.13
Further, a study in the journal Advances in Gerontology found that rats with early senile cataract and macular degeneration who received 20 mg of bilberry extract per kilo of body weight suffered no impairment of their lens and retina, while 70 percent of the control group suffered degeneration over the three month-long study.14 According to the authors:
"The results suggest that... long-term supplementation with bilberry extract is effective in prevention of macular degeneration and cataract."
Avoiding Eating This for Healthy Eyes…
Healthy vision is just as much a result of what you don’t eat as what you do. For starters, high insulin levels from excess carbohydrates can disturb the delicate choreography that normally coordinates eyeball lengthening and lens growth. And if the eyeball grows too long, the lens can no longer flatten itself enough to focus a sharp image on the retina. This theory is also consistent with observations that you’re more likely to develop myopia if you are overweight or have adult-onset diabetes, both of which involve elevated insulin levels. You’ll want to avoid sugars, especially fructose, as much as possible.
Research by Dr. Richard Johnson, Chief of the Division of Kidney Disease and Hypertension at the University of Colorado, shows that consuming 74 grams or more per day of fructose (equal to 2.5 sugary drinks) increases your risk of having blood pressure levels of 160/100 mmHg by 77 percent.
High blood pressure can cause damage to the miniscule blood vessels on your retina, obstructing free blood flow. A diet high in trans fat also appears to contribute to macular degeneration by interfering with omega-3 fats in your body. Trans fat is found in many processed foods and baked goods, including margarine, shortening, fried foods like French fries, fried chicken, doughnuts, cookies, pastries, and crackers.
Following my nutrition plan will automatically reduce, or eliminate, excess sugar and grain intake, as well as trans fats, from your diet while helping you optimize your insulin levels. As it stands, about half of Americans are eating vegetables less than 1.7 times per day and fruit less than once per day.15 Changing this dietary habit around so that you’re eating plenty of vegetables with every meal could make a major difference in your future vision health.
Outdoor Light Benefits Your Eye Health Too
Spending time outdoors offers exposure to multiple types of light, including ultraviolet B rays (UVB, which leads to the production of vitamin D) and visible bright light – two additional “nutrients” to feed your vision health. Research shows that people with nearsightedness have lower blood levels of vitamin D,16 which supports the function of muscle tissue around the lens in your eye. When exposed to outdoor light, for instance, cells in your retina trigger the release of dopamine, a neurotransmitter that slows down growth of the eye and perhaps stops the elongation of the eye during development. Nature reported:17
“Retinal dopamine is normally produced on a diurnal cycle — ramping up during the day — and it tells the eye to switch from rod-based, nighttime vision to cone-based, daytime vision. Researchers now suspect that under dim (typically indoor) lighting, the cycle is disrupted, with consequences for eye growth. ‘If our system does not get a strong enough diurnal rhythm, things go out of control,’ says [researcher Regan] Ashby, who is now at the University of Canberra. ‘The system starts to get a bit noisy and noisy means that it just grows in its own irregular fashion.’”
A study by researcher Ian Morgan of the Australian National University suggests three hours per day with light levels of at least 10,000 lux may protect children from nearsightedness.18 This is the amount of light you would be exposed to on a bright summer day. An indoor classroom or office, by comparison, would only provide about 500 lux. Like many facets of health, maintaining healthy eyes takes a comprehensive approach, one that involves eating right and paying attention to other healthy lifestyle factors like spending time outside in natural light.
In addition, if you already suffer from poor eyesight, The Bates Method, which teaches you how to retrain your eyes to relax thereby allowing you to see more clearly, may help you to improve your vision without glasses.