Your eyesight is probably the most important of your five senses.
Eye health goes hand-in-hand with general health, but a few nutrients are especially important for your eyes.
These nutrients help maintain eye function, protect your eyes against harmful light, and reduce the development of age-related degenerative diseases.
Here are 8 nutrients that benefit your eyes.
Your risk of developing an eye disease increases as you get older. The most common eye diseases include:
- Cataracts. A condition in which your eyes become clouded. Age-related cataracts are a leading cause of vision impairment and blindness around the world.
- Diabetic retinopathy. Associated with diabetes and a major cause of visual impairment and blindness, retinopathy develops when high blood sugar levels damage the blood vessels in your retina.
- Dry eye disease. A condition marked by insufficient tear fluid, which causes your eyes to dry up and leads to discomfort and potential visual problems.
- Glaucoma. A group of diseases characterized by progressive degeneration of your optic nerve, which transfers visual information from eyes to brain. Glaucoma may cause poor eyesight or blindness.
- Macular degeneration. The macula is the central part of your retina. Age-related macular degeneration (AMD) is one of the main causes of blindness in developed countries.
Although your risk of getting these conditions depends to some extent on your genes, your diet may also play a major role.
SUMMARY The most common eye conditions include cataracts, macular degeneration, glaucoma, and diabetic retinopathy. Your risk of developing these diseases depends on your age, genetics, chronic diseases, and lifestyle.
Vitamin A deficiency is one of the most common causes of blindness in the world ().
This vitamin is essential for maintaining your eyes' light-sensing cells, also known as photoreceptors.
If you don't consume enough vitamin A, you may experience night blindness, dry eyes, or even more serious conditions, depending on the severity of your deficiency ().
Vitamin A is only found in animal-derived foods. The richest dietary sources include liver, egg yolks, and dairy products.
However, you can also get vitamin A from antioxidant plant compounds called provitamin A carotenoids, found in high amounts in some fruits and vegetables.
Provitamin A carotenoids provide around 30% of people's vitamin A requirements, on average. The most efficient of them is beta-carotene, which is found in high amounts in kale, spinach, and carrots ().
SUMMARY Vitamin A deficiency may lead to night blindness and dry eyes. Vitamin A is only found in animal-derived foods, but your body can convert certain plant-based carotenoids into vitamin A.
Lutein and zeaxanthin are yellow carotenoid antioxidants known as macular pigments.
They are concentrated in the macula, the central part of your retina, which is a layer of light-sensitive cells on the back wall of your eyeball.
Lutein and zeaxanthin function as a natural sunblock. They’re thought to play a central role in protecting your eyes against harmful blue light ().
Controlled studies show that intake of lutein and zeaxanthin is proportional to their levels in your retina ().
One observational study in middle-aged and older adults noted that consuming 6 mg of lutein and/or zeaxanthin per day significantly reduced the risk of AMD.
The researchers also discovered that those with the highest intake of lutein and zeaxanthin had a 43% lower risk of macular degeneration, compared to those with the lowest intake ().
However, the evidence is not entirely consistent. One meta-analysis of six observational studies suggests that lutein and zeaxanthin only protect against late-stage AMD — not its early development stages ().
Lutein and zeaxanthin usually occur together in foods. Spinach, swiss chard, kale, parsley, pistachios, and green peas are among the best sources ().
What’s more, egg yolks, sweet corn, and red grapes may also be high in lutein and zeaxanthin ().
In fact, egg yolks are considered one of the best sources due to their high fat content. Carotenoids are better absorbed when eaten with fat, so it’s best to add some avocado or healthy oils to your leafy vegetable salad (, , ).
SUMMARY A high intake of lutein and zeaxanthin may reduce your risk of eye diseases, such as macular degeneration and cataracts.
The long-chain omega-3 fatty acids EPA and DHA are important for eye health.
DHA is found in high amounts in your retina, where it may help maintain eye function. It’s also important for brain and eye development during infancy. Thus, DHA deficiency can impair vision, especially in children (, , , ).
Evidence also shows that taking omega-3 supplements may benefit those with dry eye disease (, , , ).
One study in people with dry eyes revealed that taking EPA and DHA supplements daily for three months significantly reduced dry eye symptoms by increasing the formation of tear fluid ().
Omega-3 fatty acids may also help prevent other eye diseases. A study in middle-aged and older adults with diabetes found that taking at least 500 mg of long-chain omega-3s daily may reduce the risk of diabetic retinopathy ().
In contrast, omega-3 fatty acids are not an effective treatment for AMD (22).
The best dietary source of EPA and DHA is oily fish. Additionally, omega-3 supplements derived from fish or microalgae are widely available.
SUMMARY Getting adequate amounts of the long-chain omega-3 fatty acids EPA and DHA from oily fish or supplements may reduce your risk of several eye diseases — especially dry eyes.
Gamma-linolenic acid (GLA) is an omega-6 fatty acid found in small amounts in the modern diet.
Unlike many other omega-6 fatty acids, GLA appears to have anti-inflammatory properties (, ).
The richest sources of GLA are evening primrose oil and starflower oil.
Some evidence suggests that taking evening primrose oil may reduce the symptoms of dry eye disease.
One randomized controlled study gave women with dry eyes a daily dose of evening primrose oil with 300 mg of GLA. The study noted that their symptoms improved over a 6-month period ().
SUMMARY GLA, which is found in high amounts in evening primrose oil, may reduce symptoms of dry eye disease.
Your eyes require high amounts of antioxidants — more so than many other organs.
The antioxidant vitamin C appears to be especially important, although controlled studies on its role in eye health are lacking.
The concentration of vitamin C is higher in the aqueous humor of the eye than in any other body fluid. The aqueous humor is the liquid that fills the outermost part of your eye.
The levels of vitamin C in the aqueous humor are directly proportional to its dietary intake. In other words, you can increase its concentration by taking supplements or eating foods rich in vitamin C (, ).
Observational studies show that people with cataracts tend to have a low antioxidant status. They also indicate that people who take vitamin C supplements are less likely to get cataracts (, ).
While vitamin C appears to play a protective role in your eyes, it’s unclear whether supplements provide added benefits for those who aren't deficient.
SUMMARY Vitamin C is necessary for your eye health, and getting enough of this antioxidant may protect against cataracts.
Vitamin E is a group of fat-soluble antioxidants that protect fatty acids from harmful oxidation.
Since your retina has a high concentration of fatty acids, adequate vitamin E intake is important for optimal eye health ().
Although severe vitamin E deficiency may lead to retinal degeneration and blindness, it’s unclear whether supplements provide any additional benefits if you’re already getting enough from your diet (, ).
One analysis suggests that consuming more than 7 mg of vitamin E daily may reduce your risk of age-related cataracts by 6% ().
In contrast, randomized controlled studies indicate that vitamin E supplements do not slow or prevent the progression of cataracts (34).
SUMMARY Vitamin E deficiency may lead to visual degeneration and blindness. For those who aren't deficient, supplements probably won't provide an added benefit.
Your eyes contain high levels of zinc ().
Zinc is a part of many essential enzymes, including superoxide dismutase, which functions as an antioxidant.
It also appears to be involved in the formation of visual pigments in your retina. For this reason, zinc deficiency may lead to night blindness ().
In one study, older adults with early macular degeneration were given zinc supplements. Their macular deterioration slowed, and they maintained their visual sharpness better than those who received a placebo ().
However, further studies are needed before strong conclusions can be reached.
SUMMARY Zinc plays an important role in eye function. One study suggests that supplements may slow the early development of macular degeneration in older adults.
Healthy lifestyle habits, such as a wholesome diet and regular exercise, may help prevent many chronic diseases — including eye conditions.
Getting enough of the nutrients listed above may help reduce your risk. Other vitamins may also play a role in eye health.
However, don't neglect the rest of your body. A diet that keeps your whole body healthy will likely keep your eyes healthy, too.