Tartalomjegyzék
Tartalomjegyzék
Originally posted July 2019 / Updated November 2023
Vision is one of the most fascinating of all body functions. Visual images in the form of light travel through the transparent outer layer (the cornea), through an opening (the pupil), and then through the lens. The lens focuses the visual image into a beam that travels through the liquid of the eyeball, the vitreous humor, to the retina at the back of the eye. The light activates nerve signals that travel through the optic nerve to an area in the back of the brain that translates the nerve signal into a visual image. It truly is an amazing process.
Good vision is important for our ability to function and has been closely linked to a higher quality of life and an individual's overall health. In contrast, poor vision or visual impairment can lead to not only a lower quality of life but also a higher risk for both physical and mental health issues.
While many people experience diminished eyesight due to aging, there are important diet and lifestyle tips you can implement to help maintain and even improve your visual health.
As people age, they may experience some loss in visual function. Many will notice more difficulty reading things up close and may need reading glasses. They also might have trouble adjusting to changes in light level or distinguishing colors, such as blue from black. They are also at risk for several more serious issues regarding eye health as a result of the cumulative effects of oxidative damage to eye structures including:
Lastly, getting an annual eye exam is vital to a medical checkup, especially if you are a heavy screen time user. Regular testing can help detect eye problems at an early stage.
Over time, exposure to the sun's potentially harmful ultraviolet (UV) rays can lead to oxidative damage and accelerated aging of the lens and macula. So, one of the easiest ways to protect your eyes against cataract formation and macular degeneration is to wear sunglasses when you go outside. Not only can they help block damaging UV rays, but they can also shield your eyes from the drying effects of wind.
Protect your eyes by wearing goggles when swimming in a pool, handling hazardous chemicals, or using machinery to cut, sand, grind, or weld to keep debris and spatter from causing corneal abrasions or other eye trauma. Goggles should also be used when playing sports involving high-speed balls or players in close contact with each other to guard against eye injury. When riding a bicycle, shielding your eyes from wind and road debris is a good idea.
Regular exercise promotes eye health and is especially helpful in supporting normal intraocular pressure, which is the fluid pressure inside the eye. Even moderate aerobic exercise, such as a brisk 40-minute walk every other day, can help people with glaucoma reduce their intraocular stress. Sometimes enough to eliminate the need for medication for their condition. Yoga, relaxation exercises, and diaphragmatic breathing also lower intraocular pressure.
The adverse effects of staring at a screen from either a computer or smartphone for long periods have become so prevalent there are now terms for it, such as computer vision syndrome, digital visual fatigue, or eye strain). Symptoms can include dryness, burning, tearing, irritation in the eyes, headaches, blurred vision, and sensitivity to light.
Reducing screen time is one of the most critical steps to preserve fine vision. Here are some guidelines:
Follow the 20-20-20 rule. Look away from the screen every 20 minutes and set your gaze on an object at least 20 feet away from you for about 20 seconds. If you have digital visual eye strain symptoms, you may need to take even more breaks from staring at a screen.
Reduce excessive lighting. Eyestrain can result from excessive lighting and reflections on your screen. Use an anti-glare screen protector if there is a lot of light reflecting on your computer screen. Also, eliminate sunlight from a window with drapes or blinds and reduce bright interior lighting by using fewer light bulbs or switching to lower-intensity bulbs.
Blink more often when looking at a screen consciously. It's been discovered that people tend to blink less often when they use a computer—about one-third less often than they usually do. During these long periods of non-blinking, tears that coat the eye evaporate more quickly, causing dry eyes. Blinking frequently will keep your eyes moist to avoid dryness and irritation.
Be sure to position your screen correctly. To reduce eyestrain, your eyes should be 20 to 24 inches away from a computer screen. Keep the center of the computer screen at a position about 4 to 8 inches lower than eye level.
Lastly, note that while wearing blue light-blocking glasses is quite popular, they do not provide significant eye protection against eyestrain or retinal damage from a computer or smartphone.
Nutritional factors play an important role in the visual process and eye health, including protecting the eyes from the effects of aging. For example, a Mediterranean-type diet high in richly colored fruits and vegetables is associated with a lowered risk for cataracts and macular degeneration. This association has been known for quite some time. Initially, this protection was thought to result from increased intake of antioxidant vitamins and minerals. And these nutrients play a role in protecting eye health.
However, various plant pigments such as carotenes like lutein, zeaxanthin, and lycopene, and flavonoids like those found in berries, citrus, and green leafy vegetables were later shown to be even more significant in protecting against cataracts and macular degeneration than traditional nutritional antioxidants like vitamin C, vitamin E, and selenium.
Eating a healthy diet with colorful fruit and vegetables, including green leafy vegetables, is essential for eye health. Additionally, some specific dietary supplements that support eye health deserve special mention.
The best place to start with a dietary supplement strategy to support eye health is by building a solid nutritional foundation by taking a high-potency multivitamin that provides adequate levels of nutritional antioxidants like vitamins C and E, zinc, copper, and selenium.
These nutrients are extremely important for eye health. While something as simple as taking vitamin C or zinc has shown beneficial effects in preserving eye health, a more comprehensive antioxidant formula offers even more support.
For example, a famous study known as The Age-Related Eye Disease Study (AREDS) confirmed that a combination of nutrients would likely produce better results than any single nutrient alone. The specific daily amounts of antioxidants and zinc used by the study researchers were:
In The Age-Related Eye Disease Study 2, researchers found that participants substituting 10 mg lutein and 2 mg zeaxanthin for the beta-carotene produced even better results.
In addition to the AREDS research, several studies using various commercially available broad-based antioxidant formulas have also shown promising results. In 2017, a detailed review of 19 human double-blind studies conducted in the USA, Europe, China, and Australia further highlighted the impact of antioxidant formulas on eye health as it concluded that individuals with age-related macular degeneration may experience some delay in the progression of the vision loss with antioxidant supplementation.
The yellow carotenoid pigments lutein and zeaxanthin are critically important to the macula's health. The central part of the macula responsible for fine vision is a yellow area known as the fovea. It is yellow because of its high concentration of lutein and zeaxanthin. These yellow carotenes function in preventing oxidative damage to the macula. They also help protect against harm to the eye's lens.
A low level of lutein and zeaxanthin within the macula represents a significant risk factor for age-related degeneration of the macula. In addition, research shows that supplementing the diet with lutein and zeaxanthin helps protect against macular damage. These carotenoids can improve visual function. Specifically, lutein and zeaxanthin supplementation has significantly improved several objective measurements of visual function, including glare recovery, contrast sensitivity, and visual acuity in people with cataracts or age-related macular degeneration.
Various purple flavonoids, like the anthocyanidins of blueberry and the PCOs (procyanidolic oligomers) of grape seed and pine bark extracts, have a powerful affinity for eye structures and enhance the function of "visual purple" or rhodopsin. This pigment is responsible for the first events in the light perception and allows for night vision.
Clinical studies have subsequently shown these flavonoids to improve nighttime visual acuity, quicker adjustment to darkness, and faster restoration of visual acuity after exposure to glare in normal subjects as well as those with poor night vision and hemeralopia (an inability to see as distinctly in bright light as in dim light). Grape seed extract can enhance blood flow and improve visual function even in healthy subjects.
References:
FELELŐSSÉGKIZÁRÓ NYILATKOZAT:A jelen blognak nem célja diagnózis felállítása...
Ez a blog nem alkalmas diagnosztizálásra, kezelésre vagy orvosi tanácsadásra. További információk. Ennek a blognak a tartalma kizárólag tájékoztató jellegű. Kérjük, hogy az esetleges orvosi vagy egészségügyi diagnosztizálással vagy kezelési lehetőségekkel kapcsolatban konzultáljon orvossal vagy más egészségügyi szakemberrel. Az ezen a blogon szereplő információk nem helyettesítik az egészségügyi szakemberek tanácsát. A blogban található – konkrét termékekre vonatkozó – állítások nem alkalmasak betegségek diagnosztizálására, kezelésére, gyógyítására vagy megelőzésére.
