Written by Seamus Flynn, Optometrist
Many of the structures in our eyes deteriorate naturally over time.
Those affected most are the cornea, the crystalline lens and the retina.
We don't have to stand-by and let father-time deteriorate our vision.
The nutrition that we get from our food plays a huge role in the health and function of our eyes.
What natural changes occur within our eyes?
Over time we can experience
- Dry eyes
- Diabetic retinopathy
- Reduced night vision
- Age-related macular degeneration
How can our diet affect our ocular health?
A diet rich in antioxidants, vitamins and Omega 3 is crucial to maintain ocular health and avoid eye conditions as we get older.
The most important ones are
A study published in the Archives of ophthalmology showed that people with a diet rich in luteins and zeaxanthin had a significantly reduced chance of getting macular degeneration.
They are carotenoids and are found abundantly in fruits and vegetables particularly dark green leafy vegetables like kale, and cabbage. They are also found in high concentration in the macula, the area at the back of the eyes used for clear sharp vision and have been shown to be deficient in people with macular degeneration.
Luteins and zeaxanthin protect the eye from oxidative damage and also act as a filter for harmful high energy blue light.
What are the best foods for ocular health?
Fish, in particular oily fish, are a great source of Omega 3 which is very important for our eyes.
Omega 3 is an essential fatty acid which means it cannot be produced by the body and must be consumed. In short, in people with diets low in DHA (type of Omega 3) a toxic substance builds up and accumulates at the back of the eyes which gradually leads to vision loss conditions such as ARMD. Omega 3 fatty acids act as a protective molecule against these toxic substances and helps slow down vision loss.
The best sources of oily fish are
A study published in PubMed(1) shows that Omega 3 have a significant protective effect against retinopathy.
It is recommended to get 500mg of DHA and EPA a day for optimal eye health. A 3.5 oz (100gm) serving of wild salmon provides approximately 1500mg of EPA and DHA.
Dark green leafy vegetables such as Kale, Cabbage and Broccoli are rich in lutein and zeaxanthin which protects the macula from age related macular degeneration.
They are also a great source of anti- oxidants which protects the eyes from free radical damage that can build up over time.
These carotenoids have also been linked to a reduction in the incidence of cataracts and diabetic retinopathy.
It is recommended to get 10mg of lutein and 2mg of zeaxanthin daily.
A cup of broccoli contains around 12 mg of lutein and 1.5mg of zeaxanthin.
Eggs are a great source of lutein, zeaxanthin, Vitamin A and zinc all of which are extremely important for healthy eye functions.
There are two types of Vitamin A, plant based and animal based so the Vitamin A in eggs are called retinols as it is animal based. It is extremely important for protecting the cornea or the front surface of the eye. It also helps prevent dry eyes by maintaining the lubricating front surface layer. Along with the other anti oxidative vitamins and minerals it helps protect the retina in the back of the eye.
Lutein in eggs is 300% more bioavailable than that of vegetable sources of lutein, meaning it enters the blood circulation and is available to function much easier.
Zinc also contributes to the health of the retina and is an important component in aiding night vision.
A 2020 study(2) from the journal Clinical Nutrition found that people who consumed between two to four eggs per week had a significantly lower risk of developing age related macular degeneration than those who consumed one egg or less per week over a 15 year period.
The recommended daily intake of Vitamin A for optimal eye health is 900 micrograms (mcg) for adult men and 700 mcg for adult women.
Taking two eggs a day gives you around 15% of your recommended Vitamin A intake.
Nuts are very important to maintain healthy eyes as they are rich in Vitamin E.
The best are
- Brazil nuts
One ounce of almonds for example contains 17mg of vitamin E which is slightly more than your daily recommended intake. (15mg)
Vitamin E acts as an antioxidant which helps protect the eye from unstable free radicals that can damage eye tissue and lead to cataracts and macular degeneration.
Carrots are perhaps the most widely recognised food that is known for being good for your eyes. They don’t so much improve your vision but the Vitamin and beta carotene they contain help protect the cornea or front surface of the eyes and tear film. Vitamin A is though to act as an effective barrier to prevent penetration of bacteria and certain virus’ so helps prevent infections.
Vitamin A also helps convert light that enters your eyes into signals that tell your brain what you are seeing. This helps in low-light situations which is why Vitamin A has a reputation for improving night vision.
The daily recommended intake of vitamin A is 6 to 15 mg of beta-carotene (which is the equivalent of 10,000 to 25,000 Units of vitamin A) per day. There is 6mg of beta carotene in one large carrot which demonstrates what a great source of beta carotene it is and how important they are for eye health.
Milk and other dairy products contain Vitamin A and zinc which is important to maintain your ocular health.
We discussed earlier the importance of Vitamin A. Zinc is just as important as it acts as a “carrier molecule” and transports Vitamin from the liver to the eye.
There is a high concentration of zinc in both the retina and choroid (vascular layer) of the eye. Because of this if a person is deficient in zinc it can cause blurred vision and can cause problems with night time vision.
A daily intake of 15mg of zinc a day is recommended for optimal eye health and to ensure adequate Vitamin A levels are getting to the eye.
A pint of milk contains around 2.5mg of zinc.
Oranges and other citrus fruits such as lemons are high in Vitamin C and antioxidants.
Vitamin C has been shown to lower the risk of getting cataracts and when it is taken along with other minerals and antioxidants can reduce age related macular degeneration and loss of vision.
Our crystalline lens starts out life as a clear transparent material. As it is exposed to unstable free radicals it becomes cloudy and eventually can result in a loss of vision in the eye.
Vitamin C acts as an antioxidant which attacks the free radicals and keeps the crystalline lens clearer for longer.
8) Lean meat
Beef is rich in Vitamin A and zinc whilst chicken and pork are also rich in zinc.
Zinc helps make a pigment called melanin which absorbs and blocks harmful high energy wavelengths of light such as blue light and UV light that causes damage to the various structures of the eye.
9) Dark Chocolate
Dark chocolate contains flavonoids that act as anti-oxidants and can protect the eyes from oxidative damage. Flavonoids increase blood flow to the retina and a 2018 study(2) showed that it even improves eyesight very slightly with participants showing improvements in both visual acuity and contrast sensitivity.
Other foods that have beneficial nutrients for eye health include peaches, tangerines, mango, tomato, apricot, papaya, cantaloupe, honeydew, and avocado.
Other Eye Health Advice
Its very important to get your eyes tested every two years or every year if you are less than 18 years old, over 70 years old or diabetic.
Avoid Smoking (can cause cataracts, ARMD and glaucoma)
Protect your eyes from UV and high energy blue light