Having good vision helps you to interact with the world around you. Following a healthy lifestyle and seeing your eye care professional regularly can assist in your own eye health. A few key nutrients can help assist with maintaining eye function, protect against harmful light and reduce the development of age-related degenerative diseases of the eye. We were often told by our parents to “eat your carrots, as they are good for your eyes”, and actually there was some truth to that saying. The age related eye disease study (AREDS) completed in 2001, showed a 25 percent lower risk of worsening of age-related macular degeneration in a group supplemented with a specific blend of vitamin and mineral supplements.
There are hundreds of different eye diseases and vision problems where some have no cure, but many others are treatable. However, if detected and treated early, many eye diseases can be corrected or vision loss can be reduced by slowing down the disease progression. The good news is that it’s never too late to start taking care of your eye health! Supplementation can help you to reach the required amount of nutrients needed to benefit eye health.
Carrots cannot improve vision but the vitamins found in this vegetable can help to promote overall eye health. Carrots contain beta-carotene, which is a substance the body converts to vitamin A, an important nutrient for eye health. Carrots also contain lutein, an antioxidant found to increase pigment density in the macula.
Dry eyes are a common condition that occurs when your tears are not able to produce adequate lubrication for your eyes. Decreased tear production is caused by aging, certain medical conditions, certain medications and corneal nerve sensitivity caused by contact lens use or laser eye surgery. Increased tear evaporation is caused by blinking less often, eye allergies, environmental factors such as wind, smoke and dry air, vitamin A deficiency, eyelid problems and posterior blepharitis (dysfunction of the meibomian gland that produces an oil film on the edge of your eyelids). Eye drops containing belladonna and euphrasia assists with temporary relief of symptoms such as dry and red eyes.
Spending too much time in front of the screen can cause digital eye strain. Symptoms include headaches, neck pain and blurry vision. Generally work often involves long hours in front of the screen and cannot be avoided therefore, taking proper precautions such as good posture, avoiding very close eye contact with the screen and taking frequent breaks to give your eyes a rest will help to alleviate digital eye strain.
UV light is damaging to almost all structures of the eye. There are three types of UV light, namely UVA, UVB and UVC. UVA light emits the least energy but can cause aging of the skin. UVB light damages DNA directly and is responsible for sunburns and most UV related cancers. UVC light emits more energy than UVA and UVB but is mostly blocked by the Earth’s ozone layer. Corneal damage, cataracts and macular degeneration are possible chronic effects from UV exposure. Sources of UV light include the sun, tanning beds, halogen, fluorescent and incandescent lights, phototherapy, lasers, UV lamps used at salons to cure gel manicures, at-home UV light sanitizers and blue or high-energy visible light. Wearing sunglasses that fit well, with UVA and UVB protection and blocks light coming in around the lenses will help to protect your eyes. Also choosing a hat with a broad, dark brim that shades your eyes and reduces glare, will offer protection against harmful UV light.
The general recommendation is to get your eyes tested every two years. If you have diabetes, aged 40 or over and have a family history of glaucoma, aged 70 or over or have a child wearing glasses, it is recommended to have an eye test more often than every two years.
Diabetic retinopathy is the most common cause of vision loss for people with diabetes. It affects blood vessels in the retina (the light-sensitive layer of tissue in the back of your eye). Symptoms of diabetic retinopathy in the early stages are usually unnoticeable. However, in the late stages of this condition, blood vessels in the retina start to bleed into the vitreous (gel-like fluid that fills your eye). When this happens you may see dark, floating spots or streaks that look like cobwebs. It is very important to get treatment in the later stages of this disease to prevent your vision from deteriorating further. Controlling your diabetes is the best way to lower your risk of diabetic retinopathy.
Cataracts are the clouding of the lense of the eye. When this happens your eye can’t focus light correctly, causing blurry vision or vision loss. Cataracts are more common among the elderly but you are at increased risk of developing this condition if you smoke cigarettes, are exposed to bad air pollution frequently, consume alcohol heavily and have a family history of cataracts. Mild cataracts are treated normally with a new prescription for your glasses or contact lenses. Over time, as the condition worsens, surgery may be needed to remove the cataracts.
Glaucoma is a disease that damages your eye’s optic nerve. This usually occurs when fluid builds up in the front part of the eye causing abnormally high pressure in the eye leading to optic nerve damage. Glaucoma is the leading cause of blindness in people over the age of 60. Signs and symptoms of glaucoma depend on the type and stage of the condition. With open-angle glaucoma, symptoms experienced may include patchy blind spots in your side or central vision or tunnel vision. With acute angle-closure glaucoma, symptoms experienced may include severe headaches, eye pain, nausea and vomiting, blurred vision, halos around lights and eye redness. Glaucoma damage cannot be reversed, but regular eye checkups can help detect this condition in the early stages. Treatment options also include lowering your eye pressure, prescription eye drops, oral medications, laser treatment, surgery or a combination of any of these.
Age related macular degeneration (AMD) is the most common cause of vision loss in people aged 50 years and older. Only the center of vision is affected without losing total vision. In this condition a part of the retina called the macula is damaged. In the early stages of this condition, people rarely have symptoms but during the later stages symptoms such as losing the ability to drive, to see faces and read smaller print is experienced. Dry AMD is the most common type and occurs as the light-sensitive cells in the macula slowly break down. With this type, vision loss is normally slow and gradual. Wet AMD is not as common and occurs when abnormal blood vessels start to grow beneath the retina. This type of AMD leads to more severe vision loss. Risk factors include being 50 years and older, eating a diet high in saturated fat (butter, processed meats, cakes, biscuits and cheese), smoking and high blood pressure. There is no treatment for dry AMD but vision rehabilitation programs can be used to build visual skills. The main treatment for wet AMD is the injection of medications called anti-VEGF (vascular endothelial growth factor) agents.
The AREDS (Age-Related Eye Disease Study) and AREDS2 are major clinical trials sponsored by the National Eye Institute (NEI). The AREDS studies were designed to learn more about the natural history and risk factors of age-related macular degeneration (AMD) and cataract. Researchers tested whether taking nutritional supplements could prevent or slow these diseases.
The AREDS study includes oral supplementation with antioxidant vitamins C and E, beta carotene, and zinc. This formula has been shown to reduce the risk of progression to advanced age-related macular degeneration (AMD).AREDS2 was designed to test whether adding lutein and zeaxanthin, DHA + EPA to the AREDS formulation might further reduce the risk of progression to advanced AMD. However, this had no additional overall effect on the risk of advanced AMD. It was noted that trial participants who took AREDS containing lutein and zeaxanthin and no beta-carotene had a reduction in risk of advanced AMD, compared with those who took AREDS with beta-carotene.
|Nutrient||AREDS formula*||AREDS2 formula|
|Copper (cupric oxide) - added to avoid zinc related copper deficiency||2mg||2mg|
*Not recommended for current or former smokers
The AREDS and AREDS2 formulas are not replacements for multivitamins and can be taken together. In AREDS, it was found that two-thirds of the study participants took multivitamins along with the AREDS formulation and in AREDS2, almost nine of ten participants took multivitamins.
In the AREDS2 trial, current smokers or those who had stopped smoking less than a year before enrollment were excluded from receiving beta-carotene. Despite this precaution, lung cancers were observed in 2% of participants who took an AREDS formulation with beta-carotene, compared with 0.9% of participants who took an AREDS formulation without beta-carotene. Findings found that across both groups, about 91% of participants who developed lung cancer were former smokers. A conclusion was made that former smokers who took AREDS with beta-carotene had a higher incidence of lung cancer.
Vitamin A is available in two forms: Beta-carotene is a provitamin that is converted into vitamin A in the body and vitamin A is an antioxidant that protects the body against free radicals. This nutrient plays an important role in vision by maintaining a clear cornea (outside covering of your eye). A deficiency of vitamin A can cause a white spot on the conjunctiva known as Bitot’s spot, impair night vision and lead to blindness. Although vitamin A deficiency is rare in developed countries, if unaddressed it can lead to Xerophthalmia which is a progressive eye disease that begins with night blindness. The richest food sources of beta-carotene include any yellow, orange and green leafy fruit and vegetables such as carrots, sweet potatoes, sweet melon, butternut, broccoli, lettuce and winter squash. In general, the more intense the colour of the fruit or vegetable, the more beta-carotene it contains. Foods rich in vitamin A include sweet potatoes, leafy green vegetables, pumpkins and bell peppers.
Vitamin C is also known as ascorbic acid and plays a role in the growth, development and repair of all body tissues. It is an essential vitamin found in food sources such as citrus fruit, peppers, strawberries, blackcurrants, broccoli, brussel sprouts and potatoes. Vitamin C has been found to reduce the risk of cataract progression. Cataracts cannot be avoided as it is a condition that comes with age but supplementation and eating foods high in vitamin C will prevent worsening of cataracts. This nutrient is also required to make collagen which is a protein that provides structure to the cornea and sclera in the eye.
Vitamin E is a fat soluble vitamin with many forms but alpha-tocopherol is the only form used by the body. This nutrient functions as an antioxidant, enhances immune function and prevents clots from forming in heart arteries. Food sources rich in vitamin E include nuts, seeds, cooking oils, salmon, avocado and leafy green vegetables. Vitamin E has been shown to protect your eye cells from damage by free radicals (harmful and unstable radicals) and may help to prevent age related cataracts.
Bilberry is a fruit that closely resembles blueberries. Bilberry fruit contains chemicals known as anthocyanosides, which is a plant pigment that has outstanding antioxidant properties. It has also been found useful as treatment for retinopathy (damage to the retina) as anthocyanosides have a function by protecting the retina. This nutrient has been shown to improve night vision and exhibit protective effects against macular degeneration, glaucoma, and cataracts.
Ginkgo Biloba leaf extract is produced from the leaves of the Ginkgo Biloba tree native to China. This nutrient has antioxidant properties and benefits the CNS and vascular conditions by improving circulation. Ginkgo biloba may be an effective treatment for glaucoma because it has been shown to improve blood flow, relax smooth muscle and protect neurons from damage.
Omega 3 fatty acids are found naturally in fatty fish such as salmon, trout, pilchards, sardine, fresh tuna (not tinned) and mackerel. Studies have found that this nutrient may help protect eyes from macular degeneration, dry eye syndrome and glaucoma. It is often difficult meeting daily omega 3 requirements, therefore supplements are a convenient and consistent source of omega 3.
Docosahexaenoic acid (DHA) is prevalent in the retina. Photoreceptors, the neuronal cells that make vision possible, have more DHA than any other cells in our body. Healthy levels of DHA in photoreceptors maximize retinal function and protect against damage from bright light exposure and oxidative stress which is increased in people with retinal degenerative diseases.
Lutein is an antioxidant which belongs to the carotenoid group. Food sources such as leafy greens vegetables as well as orange and yellow vegetables are rich in Lutein. This nutrient is important for maintaining eye health and reducing the risk of macular degeneration and cataracts. It is difficult to meet the required amounts of lutein from diet alone, therefore supplementation can help to meet recommended intake (6 to 10mg/day).
Zeaxanthin is a fat soluble carotenoid found in the cells of the human eye. It is a powerful antioxidant that has been shown to reduce the risk of age-related macular degeneration, glaucoma, and cataracts. This nutrient can be found in many fruits, vegetables and animal products such as egg yolks.
Copper is an essential mineral necessary for a range of bodily functions. It plays an important role in forming red blood cells and maintaining nerve cells and the immune system. Although copper deficiency is rare, it has been found to lead to vision loss. Copper benefits the eyes by improving connectivity within the tissues of the eyes. This mineral also helps to keep the pigmentation and melanin in the eye vibrant and bright for longer. Copper has been found to prevent eye conditions such as age related macular degeneration.
Zinc is an essential mineral found throughout your body. It is involved in many aspects of cellular metabolism and plays a role in enhancing immune function, protein and DNA synthesis, wound healing and cell signaling and division. Food sources of zinc include oysters, chicken, red meat, legumes and nuts. Zinc is an important mineral involved in transporting vitamin A from the liver to the retina to produce melanin which is a protective pigment in the eyes. It has been found that zinc deficiency is linked to impaired vision (poor night and cloudy vision).