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Friday, 8 July 2016

Nearsighted in the Future?

Nearsightedness


Researchers estimate nearly 50 percent of the world population will be nearsighted by 2050. Today, the prevalence among students in Asia is over 80 percent. Discover what you can do to reduce your risk and protect your sight.


June 29, 2016

Story at-a-glance

  • Between the early 1970s and early 2000s, the percentage of people diagnosed with myopia (nearsightedness) jumped from 25 percent to 42 percent
  • Wearing glasses is a short-term fix for a long-term problem and may increase the amount of distance vision you lose
  • Contacts and LASIK surgery have significant and dangerous side effects. There are simple changes you can make to your daily routine that may help reduce your risk of developing or worsening nearsightedness
By Dr. Mercola
Nearsightedness, or myopia, is a condition of the eyes making it difficult to see distant objects. With myopia you are able to see objects up close easier, such as books and your cell phone. The distance at which the objects begin to become blurry can change over time.
The number of people suffering from nearsightedness has grown significantly in the past years. In the early 1970s, the number of people affected was approximately 25 percent of those living in the U.S. In just 30 short years, that percentage jumped to 42 percent.1 
Now, a meta-analysis of 145 studies involving over 2 million participants predicts that nearly half of the world will be wearing glasses by the year 2050.2 The purpose of the study was to evaluate the increasing prevalence of myopia and high myopia throughout the world.
Researchers concluded that almost 1 billion people will suffer from ocular complications or vision loss from high myopia.
Nearly 10 percent of people or 938 million people will suffer from high myopia, where their nearsighted condition puts them at greater risk for glaucoma, retinal detachment, cataracts and macular degeneration.3

How Your Eye Functions

What you see is not interpreted in your eyes but rather in your brain. Light passes through the front of your eye (cornea) and the lens, and these structures help focus the light on the retina at the back of your eye.
The cells in the retina then convert the light to electrochemical impulses making their way over the optic nerve and into your brain. The front of your eye acts like a camera lens, letting more light in at night and less during the day. This is why your pupils are larger at night, to let in more light and allow you to see.4
Glasses are used to change the focus of light on your retina and improve your vision. However, while the intention is good, the ultimate results may not be as good.
During the day, your vision fluctuates. Glasses are not able to accommodate these natural changes in your vision, and therefore the static focus of the lens in your glasses can negatively affect the way your eye functions.
Imagine your glasses are like an ankle brace. In the short term, an ankle brace can help your body to heal from a sprained ankle, offering stability and protection to the joint.
However, worn over a long period of time, the muscles in the ankle become weak from disuse and you are more prone to another ankle sprain.
In the short term, glasses will help you to see more clearly. However, over a long period of time, your eye muscle strength may change, making your unaided vision worse.

Increasing Problems With Vision Possibly Triggered by a Variety of Factors



Your vision is not affected by just one factor in your environment. This video explains some of those factors. For many years, the science community laid the blame for nearsightedness at the doorstep of your genes.
However, the meteoric rise in the number of people affected, coupled with sociological changes and the disparity between the number affected in industrialized nations versus poor countries has led researchers to evaluate other potential causes.
In the meta-analysis published in Ophthalmology, researchers postulated the reasons for the increasing number of people with myopia were related to changes in the environment. According to the researchers:
"[T]he projected increases in myopia and high myopia are widely considered to be driven by environmental factors … principally lifestyle changes resulting from a combination of decreased time outdoors and increased near-work activities"5
Near work activities include work on a computer screen, reading books and cell phone usage. The number of children using hand held computer devices has increased dramatically in the past decade, reducing the number of hours spent outside.
Some believe this deadly combination also reduces the amount of time your eyes absorb sunlight, necessary for eye health. Another study points to high expectations within the school system to explain the increasing number of children in Asia who graduate from high school or college with glasses.6
This massive rise may be attributed to a lack of sunlight from hours spent doing school work. In the U.K., 20 to 30 percent of children wear glasses for myopia. In years past, this was also the rate in Asia.7
However today that rate is over 80 percent of all children and quickly approaching 90 percent. Ian Morgan, Ph.D. of the Australian National University led the study and called this a "major health problem."

What You Eat Impacts Your Eyesight

Interesting links have also been made between groups of people who have not embraced a Western diet and those who have. Countries with rising prevalence rates of myopia have adopted a Western diet regimen, high in refined carbohydrates and low in real foods.
This observation led to the hypothesis that increased levels of blood sugar and insulin may induce nearsightedness.8
Diets packed with foods triggering the release of insulin increases the number of individuals diagnosed with diabetes, especially in those populations not previously exposed to these diet choices.9,10 
Other research has also linked high levels of insulin and blood sugar to increasing rates of myopia, with or without the diagnosis of diabetes.11
Researchers propose it is a relationship between the high levels of insulin and scleral growth that leads to myopia.12 The sclera is the white, fibrous and protective outer layer of your eye, often referred to as the white of your eye.
Overgrowth of the sclera changes the shape of your eye, and therefore the direction light passes through the cornea and lens, affecting your eyesight.
The link found between myopia and high insulin levels does not require a diagnosis of diabetes, but rather just a diet high in net carbohydrates (total carbs minus fiber), triggering the release of large amounts of insulin.13

Glasses Prescribed at Different Rates Depending Upon the Professional

Increasing rates of nearsightedness are occurring in children, however the diagnosis of myopia will depend upon the professional who evaluates them.
Research published in the Journal of American Association for Pediatric Ophthalmology and Strabismus discovered 35 percent of the children in the study who were evaluated by an optometrist received glasses for nearsightedness.
This is contrasted with the 11 percent examined by ophthalmologists and the 1.8 examined by pediatric ophthalmologists who received glasses.14
These significant differences suggest the potential your child will be diagnosed withmyopia and prescribed glasses is far higher if they are evaluated by an optometrist than an ophthalmologist or pediatric ophthalmologist. The study concluded a significant percentage of participants were prescribed glasses unnecessarily.

Contacts Are Not the Answer

While you may enjoy the appearance of not wearing glasses, contact lenses are not the answer you may have hoped for. Much like glasses, contact lenses work by changing the direction light enters your eye.
The lenses float on a layer of tears over the surface of your cornea. They have the same effect of worsening your unaided vision over time, as well as other more dangerous side effects.15 Eye infections and corneal scratches are two of the more common risks you may experience.
Wearing lenses also changes the environment and the type of bacteria living in your eye. In one study, researchers found if you wear contact lenses you have three times the proportion of bacterial species living on the surface of your eye.16
Eye infections are different from a common sty or pink eye. Although both are uncomfortable, the former doesn't increase your risk of losing your sight. Infections affecting your eyeball will cause redness, sensitivity to light, blurred vision, swelling and pain. It is essential you get immediate medical attention to reduce your risk of permanent damage.17
Since the introduction of contact lenses in the 1970s, the number of people suffering from corneal abrasions and ulcerations has dramatically increased. These openings in the surface of your eye increase the risk of infection in an environment already experiencing higher numbers of bacterial growth than normal.18
Acanthamoeba is a tiny, single-celled organism commonly found in your tap water. Wearing contact lenses in the shower, or poor contact lens hygiene, can lead to an infection called Acanthamoeba keratitis (AK), which may lead to blindness, or even loss of your eye.19

What About Lasik?

Another option to correct vision you may have explored is Laser-Assisted in Situ Keratomileusis (LASIK) surgery. The promise of a quick, computer-driven and laser surgery on your cornea to correct your vision, is actually nothing more than a promise.
In the short term, LASIK surgery typically provides amazing results. However, recent studies have pointed out complications from the procedure, including diminished sight after six months requiring glasses for night vision or reading. Other potential complications associated with LASIK surgery include:20
Vision loss
Vision loss following this procedure cannot be corrected with contacts, glasses or surgery.
Severe dry eye
After surgery your eye may not be able to produce enough tears, which may reduce visual quality, increase risk of infection, increase pain in the eye or cause blurry vision.
Chronic corneal neuropathic pain
Disruption of the nerve endings during the surgery may cause unrelenting, excruciating eye pain.21,22
Debilitating visual symptoms
These symptoms can include halos, glare or double vision. Some patients lose the ability to differentiate objects in low contrast situations, such as in the fog or at night. Lost night vision is one of the more common side effects of the procedure.
Possible secondary correction
You may require a second surgery if your vision was undercorrected. However, if it was overcorrected there is no procedure to reverse the process.23

Small Changes Reap Big Rewards

Making small changes in your lifestyle choices may reduce your risk of myopia. It would also be wise to teach your children these strategies, to help protect their eyesight and reduce their risk of developing the condition.
Reduce the amount of close work
Computers, digital games, reading and bookkeeping are just a few of the activities involving close work.
Spend time in sunshine
Sunlight may release dopamine in your retina, slowing the growth of your eye and therefore possibly slowing the elongation of the eye and changes to your sight.24
Normalize your blood sugar
Higher than normal levels of blood sugar and insulin may increase growth of scleral cells and change your eyesight.25
Astaxanthin and omega-3 supplementation
Astaxanthin, a potent antioxidant, may help prevent blindness and may offer protection against a number of eye diseases, including macular degeneration, which is the No.1 cause of blindness.
Omega-3 is also important for  healthy vision.26 My favorite source of omega-3 is krill oil.
Practice distance vision
One of the high risk factors for developing nearsightedness is close work. Lift your eyes from your computer every 15 minutes to focus on objects at least 20 feet from where you're sitting.
Optimize computer use
Sit at least an arms-length from your computer, reduce the glare from your screen using an anti-glare screen cover and make your computer screen the brightest light in the room.
Vitamin C supplementation
Vitamin C helps protect your vision and protects your eyes from the formation of cataracts.
Relax your eye muscles
Stressors can increase the tension in the muscles controlling your eyes, and therefore change the shape of the eye.
By using relaxation methods to reduce the tension in your eye muscles, such as the Bates Method I used, you may experience the same success I have. I no longer use glasses for distance or reading to correct my vision.
Reduce blue light
Blue light from your computer screen may reduce your production of melatonin, reducing your sleep and increasing your risk of diabetes. Insulin resistance increases your risk of myopia.27
Avoid trans fats
Trans fats may contribute to macular degeneration and may interfere with omega-3 fatty acids.
http://articles.mercola.com/sites/articles/archive/2016/06/29/myopia-increasing-rates.aspx