Farsightedness - Presbopia & Hyperopia
Farsightedness is the ability to see clearly at a distance, but near objects are unclear. Early in life, this is called hyperopia. After about age 40, the cause is different, and it is known as presbyopia.
Vitamins & Supplements
In order to have perfect vision, the eyeball needs to be slightly ovoid (egg-shaped). Newborn children have eyeballs that are nearly spherical; therefore, the ability to focus is limited to about 20 centimeters for the first few months. Their eyes gradually adjust and their hyperopia lessens as they mature. The flexible lens of the eye becomes able to adjust between near and far vision. But after about 40 years old (middle age), the lens becomes less flexible, making it more difficult to see details clearly, up close, without glasses. This is called presbyopia.
How the Eye Focuses
The transparent cornea that covers the front of the eye has the most focusing power of the eye. But its curvature, and therefore its focusing capacity, is fixed. It is the flexible lens behind the cornea that fine-tunes total curvature to correctly aim incoming light on the retina. As the retina nerve cells pick up and transmit sensory information to the visual cortex in the brain, fine muscles in the ciliary body cause the lens to flatten or bulge in order to focus on objects near and far.
In cases of farsightedness, either because the eyeball is too short (hyperopia) or the lens is too inflexible (presbyopia), the incoming light overshoots the mark and is focused just behind the retina rather than right on it. The result is blurriness.
Farsightedness is caused by either a smaller than normal length of the eye or a relatively flat curvature of the cornea. It can be overcome somewhat by strengthening the focusing power of the lens of the eye to help see nearby objects more clearly. Ciliary muscles control the flexing of the lens to focus near and far, and eye exercises may help to keep those muscles healthy.
With aging, the lens itself becomes less flexible. The shape of the eye may still be too short (hyperopia) or too long (myopia), but in addition, the muscles of the ciliary body are less effective, because the lens itself becomes increasingly inflexible.
The human lens grows throughout our life. It is a closed system (although nutrients continue to nourish the living tissue of lens cells) in which continuous restructuring is needed to accommodate additional growth. Increasing density of lens proteins also increases inflexibility. The integrity of the lens depends, at least in part, upon the bioavailability of nutrients and antioxidants that are moved in and out of the lens. The lens has a microcirculation system that operates in place of blood vessels. It has been proposed that this system is a flow of ions that generates a flow of water through the lens. An extracellular flow of water moves nutrients into the lens; an intracellular flow of water moves wastes out of the lens.
As the lens ages, not only does its transparency decrease, but water movement within the lens slows, proteins and aggregates accumulate, glycation (bonding with sugars) increases, lipids accumulate, and glutathione and vitamin C (ascorbic acid) decreases. After about the age of 40, a barrier to transporting glutathione to the interior of the lens develops around the nucleus of the lens, which accounts for lowered glutathione levels. As the nucleus becomes more rigid, presbyopia develops, and in some people, accumulation of aggregates leads to the development of cataracts.
Causes can include genetics, stress, and age. Emotional considerations at an early age may also factor in. For example, a child who does not want to internalize feelings that are due to their environment can actually affect vision and create farsightedness (not wanting to see things near).
The symptom of farsightedness is that far vision is good, but near vision is poor. The patient experiences blurry vision and is more easily subject to eyestrain or even headaches when doing close work, unless vision is corrected with eyeglasses. Some signs of presbyopia include the tendency to hold reading materials at arm's length, blurred vision at normal reading distance and eye fatigue along with headaches when doing close work.
Glasses or contacts are prescribed to correct the refractive error. The prescriptions tend to become stronger every one to two years.
Vision is not static and changes over time. Even without any pathology, vision tends to weaken as we age. As eye muscles become weaker, the eye lens becomes less flexible. Compounding these changes, our ability to digest nutrients and deliver them to our eyes gets compromised. Much, however, can be done to maintain healthy vision and reduce the risk of future eye disease through diet, regular exercise (including daily eye exercises), and targeted supplementation. These approaches can also reduce the risk of future eye disease.
Because the literature suggests that risk of cataracts is lessened by diets rich in vitamin C, lutein/zeaxanthin, B vitamins, and omega-3 fatty acids, it may be that such a diet will also help protect the aging lens in other ways.
A combination of vision therapy (daily eye exercises), nutrition, and lifestyle changes can help slow down the progression of presbyopia, and possibly even improve vision.
Self Help Tips
Here are some tips on protecting one's general vision:
- Supplement with nutrients to support the functioning of the eye including antioxidants which are found in high concentrations in the eye.
- Nutrition, diet & lifestyle protocol - see our recommendations for diet and lifestyle tips for detailed information.
- Eye exercises can help to bring energy to the eyes and improve circulation, thereby improving drainage of toxins or congestion from the eyes. These are free general eye exercises and acupressure points for overall eye health.
- Also see our collection of eye exercise videos.
- Computer user? If you are on the computer for many hours, there are additional risks for your vision. Please review our section on glaucoma, computer fatigue syndrome and the research on computer eye strain.
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