Healthy eyes?
ALTHOUGH many aspects of vision remain a mystery, certain requirements must be met for normal vision to occur. Light enters the eye and interacts with the specialised nerve cells in the retina – rods and cones (photoreceptors) – to create a nerve impulse, and the nerve impulse must then be transmitted to the visual area of the brain.
Eye strain
Because our eyes are in use most of our waking hours, they naturally get tired. Other than simple overuse, eye-strain can also be due to a number of factors: a weakness of the ciliary or eye muscle, improper lighting, or overall tension and anxiety. But a constant close focus tends to cause more eye-strain.
Ageing
When ageing individuals are asked what they fear most, one of the most frequently cited concerns is going blind. Elderly people encounter astoundingly high rates of cataract and macular degeneration. The good news is that degenerative eye disease is not inevitable. Scientific studies conclusively show that the risk can be lessened through lifestyle and nutritional changes.
New studies have revealed that common diseases of the eye are mostly preventable. Prevention of disease requires awareness, basic knowledge, and a plan. The two major eye diseases for which we all are at risk are cataracts and macular degeneration.
Cataracts
The lens, which focuses light rays onto the retina, is supposed to be transparent. When the lenses become opaque, the opaque areas are called cataracts. Cataracts are the leading cause of impaired vision and blindness worldwide, affecting up to 40% of people over the age of 75.
They are most often caused by overexposure to intense light (sunlight) but other factors can contribute to them: cigarette smoking, hereditary factors, injury, diabetes and certain medications. Cataracts usually develop slowly, starting with blurred vision, spots, and the impression that a film is covering the eyes.
Macular degeneration
Think of the retina as the film in a camera (non-digital). In the retina, rods and cones (photoreceptor cells) convert the image into electrical impulses, which travel to the brain via the optic nerve. That is how the eye, or rather, the brain, sees image.
The most sensitive part of the retina is the macula. Here, millions of cones are tightly packed to create a high-resolution image that produces the sharp central vision needed for activities like reading, writing, driving and even recognising faces.
It is the macula that can deteriorate with age. Because the macula alone is affected, central vision is lost (though total blindness is avoided). Macular degeneration causes no pain. Macular degeneration affects one-third of adults over the age of 75, and is the principal cause of visual disability in people over 65 years of age. Age is by far the greatest risk factor.
Nutritional factors
Research shows that certain nutrients are important for good vision.
The origin of many eye disorders can also be attributed to free radicals caused by overexposure to sunlight. In a nutshell, a free radical is a highly reactive molecule that can damage eye tissues, causing cataract and macular degeneration.
Lutein
Lutein is a carotenoid nutrient found in dark green, leafy vegetables like spinach, as well as in other foods such as corn and egg yolk. Of the 600 or so carotenoids present naturally, only 20 or so carotenoids can be detected in our blood. Of those, nature has chosen only Lutein and Zeaxanthin to be present in the eyes. They are found in all parts of the eye, but occur in concentrations nearly 1,000 times greater in the macula section of the retina than in any other tissue in the body.
Lutein and Zeaxanthin give the macula its striking yellow colour and are often referred to as the “macular pigments”. Lutein found in the macula region of the eye helps shield the eyes from damaging light, particularly blue light (the most damaging) from the visible light spectrum. Lutein absorbs blue light and this is critical for the protection of the lens, retina and macular portions of the eye.
Lutein is a powerful fat-soluble antioxidant and protects the lens, retina and macula of the eyes against free radical damage. The body cannot manufacture Lutein and as we grow older, concentrations of Lutein in the eyes decline – leaving the eyes susceptible to age-related eye disorders. Fortunately, taking Lutein supplements can help increase its concentration in the lens, retina and macula.
Numerous clinical studies have shown that Lutein is not only deposited in the macula but also in the lens of the eye. Research suggests that, once there, Lutein helps to reduce the risk of developing age-related macular degeneration (AMD) and may also play a role in reducing the risk of developing cataract.
Bilberry
Bilberry contains potent antioxidants that protect and improve micro-circulation, that is, the circulation of blood through the capillaries. These antioxidant pigments, called anthocyanosides or anthocyanins, protect cells in the circulatory system, keeping them flexible and provide better blood flow, delivering nutrients and oxygen to capillary-rich organs such as the retina.
Researchers have also found that Bilberry affects enzymes responsible for energy production in the eye, which is especially important for good vision under poor light conditions, including night vision.
Supplements
There are numerous supplements for eye health. It is important to ensure that the product includes Lutein and has at least 10mg of Lutein (per day’s serving) to maintain proper eye health.
Generally, when shopping for herbal product(s), one should preferably choose products that contain standardised extract(s) of herbs as they can guarantee the consistency of the product.