EPTThe theory is that not wearing glasses or for children or mild cases reading glasses will make the eyes relax because it need to focus at something which appears far away as opposed to straining the eye straining when we wear glasses, since minus lenses brings things closer to us and we need to contract our muscles more to look at near objects.
Edit: Now I think about it, the papers look horrendously bogus but there is still one maybe left http://www.myopia.org/bifocals.htm .
My objective is not to warn you of a conspiracy but to find out about this plus lenses method.
Here's a much more better looking website: as recommended by someone who was successful with this method.
http://www.i-see.org/myopia_correction.html
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The above considerations strongly suggest that corrective lenses for myopia, particularly in children, will cause myopia to increase: unaided distance vision will get worse, dependence on eyeglasses will increase, and a stronger prescription will be required for perfectly clear distance vision. However, the precise effect that corrective lenses have on the course of myopia has not been tested. In studies of children using who wear corrective lenses, the amount of myopia has been found to increase for a period of years as the strength of the lenses are increased. Some modifications of the standard prescription have been tested, including a slightly lowered prescription, or spectacles with a weaker-powered area in the bottom half to be used for reading (bifocals). In randomized clinical studies involving such glasses, the course of myopia has been found to be approximately the same as with normal glasses. This does not mean that minus lenses do not cause increased myopia. Even a less than full prescription amounts to an increase in "minus" power at all distances, and in the case of bifocals, the minus lens segment, though intended for distance viewing, can be used for midrange and near work as well. In the one peer-reviewed study that actually compared those who did not wear glasses at all with those who wore them as normally prescribed, the full time minus lens wearers had an increase in their myopia twice as much as those who never wore their glasses. Unfortunately the experiment was retrospective in design and the sample size was too small to permit a firm conclusion.
Summary: "Hypothesis" strongly suggestive but Inconclusive
Basically, the theory is that minus lenses (conventional lenses) worsens our eyesight, because how it works is that it brings things closer, they bend the rays to achieve that. Then we constantly have to strain because we need to contract out ciliary muscles to thicken our lenses to focus on something near. This constant straining worsens our eye sight - and allows people to sell more glasses as we change them form time to time.
With plus lenses for reading, our eyes have to relax as if we were looking at something far away. When things are blurred or even just a little blurred (The ideal reading positon), our eyes relax - as opposed to contracting (tensing) when looking at something near. Anyone who has glasses should be able to relate to this. When I first started wearing glasses, I've had headaches and even until now, every time I take off my glasses my eyes always feel relaxed.
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ome links to my resources:
http://schwerdfeger.name/articles/pluslens.shtml - Someone's success story of plus lenses with explanations of how it works.
http://www.youtube.com/MyopiaPrevention
However they say that only people who have mild myopia can correct their vision back to 20/20. If you're like me I guess we should just relax our eyes more but only wearing our glasses if we really need it like for driving.
EDITED AGAIN to bring in more facts (seemingly):
He claims negative lenses are part of a conspiracy to worsen our eyesight so we keep buying glasses. But what he advocates is being able to relax your eyes, something we usually don't do if we are nearsighted, we always squint.
http://schwerdfeger.name/articles/pluslens.shtml - Someone's success story of plus lenses with explanations of how it works.
http://www.youtube.com/MyopiaPrevention
However they say that only people who have mild myopia can correct their vision back to 20/20. If you're like me I guess we should just relax our eyes more but only wearing our glasses if we really need it like for driving.
EDITED AGAIN to bring in more facts (seemingly):
The point of all this is that if you want to do something about preventing myopia, it is a waste of time to consult an ophthalmologist since it would be highly unlikely to find one who understands or has any interest in myopia prevention. The best course of action is to contact local optometrists to see if you can find one who uses plus lenses or takes other steps to prevent myopia.
Generally speaking, the M.D.'s specialize in those vision problems requiring drugs or surgery. The O.D.'s specialize in non-medical vision problems. Consequently, there is no more reason to turn to an M.D. for the treatment of acquired myopia than there is to turn to an O.D. for a problem requiring drugs or surgery.
Generally speaking, the M.D.'s specialize in those vision problems requiring drugs or surgery. The O.D.'s specialize in non-medical vision problems. Consequently, there is no more reason to turn to an M.D. for the treatment of acquired myopia than there is to turn to an O.D. for a problem requiring drugs or surgery.
He claims negative lenses are part of a conspiracy to worsen our eyesight so we keep buying glasses. But what he advocates is being able to relax your eyes, something we usually don't do if we are nearsighted, we always squint.
Is there anyone who might be educated on this subject? Tell me what you think.
On November 09 2010 20:17 munchmunch wrote:
Ok, since I love a mystery, I just spent an hour typing stuff into PubMed. Mainly I learned that I don't know anything about medicine. But, as far as I can make out, the situation seems to be this: there are a lot of studies on controlling myopia progression in children by varying how much and what kind of eyeglasses they wear. These studies include giving kids reading glasses (ie. plus lenses). But the best results seem to come from giving the kids bifocals (I guess that way they have the appropriate glasses for near work right at hand). However, if there is a positive effect, it is small: at most 0.5 diopters per two years, and likely much smaller.
A recent paper:
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Randomized Trial of Effect of Bifocal and Prismatic Bifocal Spectacles on Myopic Progression --- ARCH OPHTHALMOL / VOL 128 (NO. 1), JAN 2010.
A number of well-designed prospective studies have investigated the effect of positive lenses, in bifocal or multifocal form, on myopic progression in children. However, bifocals and multifocals have proven to be relatively ineffective myopia-control treatments in children. Of the many myopia-control studies, the study by Leung and Brown showed the greatest treatment effect (myopia control, -0.47 D per 2 years with multifocals). ... A later multifocal study conducted in Hong Kong ... failed to replicate the results (myopic control, -0.14 D per 2 years with multifocals) [no significant treatment effect].
Not surprisingly, wikipedia has a good section on this:
http://en.wikipedia.org/wiki/Myopia#Myopia_control
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Various methods have been employed in an attempt to decrease the progression of myopia.[30] Dr Chua Weihan and his team at National Eye Centre Singapore have conducted large scale studies on the effect of Atropine of varying strength in stabilizing, and in some case, reducing myopia. The use of reading glasses when doing close work may provide success by reducing or eliminating the need to accommodate. Altering the use of eyeglasses between full-time, part-time, and not at all does not appear to alter myopia progression.[75][76] The American Optometric Association's Clinical Practice Guidelines for Myopia refers to numerous studies which indicated the effectiveness of bifocal lenses and recommends it as the method for "Myopia Control".[8] In some studies, bifocal and progressive lenses have not shown significant differences in altering the progression of myopia.[30] More recently robust studies on children have shown that Orthokeratology[77] and Centre Distance bifocal contact lenses[78] may arrest myopic development.
Basically, eyeglasses don't do well compared to contact lenses and other treatment methods. Finally, note that the myopia of the kids who go through this treatment gets worse, just at a slightly slower rate than other kids. So the idea that wearing reading glasses can fix myopia is still pretty silly.
Ok, since I love a mystery, I just spent an hour typing stuff into PubMed. Mainly I learned that I don't know anything about medicine. But, as far as I can make out, the situation seems to be this: there are a lot of studies on controlling myopia progression in children by varying how much and what kind of eyeglasses they wear. These studies include giving kids reading glasses (ie. plus lenses). But the best results seem to come from giving the kids bifocals (I guess that way they have the appropriate glasses for near work right at hand). However, if there is a positive effect, it is small: at most 0.5 diopters per two years, and likely much smaller.
A recent paper:
+ Show Spoiler +
Randomized Trial of Effect of Bifocal and Prismatic Bifocal Spectacles on Myopic Progression --- ARCH OPHTHALMOL / VOL 128 (NO. 1), JAN 2010.
A number of well-designed prospective studies have investigated the effect of positive lenses, in bifocal or multifocal form, on myopic progression in children. However, bifocals and multifocals have proven to be relatively ineffective myopia-control treatments in children. Of the many myopia-control studies, the study by Leung and Brown showed the greatest treatment effect (myopia control, -0.47 D per 2 years with multifocals). ... A later multifocal study conducted in Hong Kong ... failed to replicate the results (myopic control, -0.14 D per 2 years with multifocals) [no significant treatment effect].
Not surprisingly, wikipedia has a good section on this:
http://en.wikipedia.org/wiki/Myopia#Myopia_control
+ Show Spoiler +
Various methods have been employed in an attempt to decrease the progression of myopia.[30] Dr Chua Weihan and his team at National Eye Centre Singapore have conducted large scale studies on the effect of Atropine of varying strength in stabilizing, and in some case, reducing myopia. The use of reading glasses when doing close work may provide success by reducing or eliminating the need to accommodate. Altering the use of eyeglasses between full-time, part-time, and not at all does not appear to alter myopia progression.[75][76] The American Optometric Association's Clinical Practice Guidelines for Myopia refers to numerous studies which indicated the effectiveness of bifocal lenses and recommends it as the method for "Myopia Control".[8] In some studies, bifocal and progressive lenses have not shown significant differences in altering the progression of myopia.[30] More recently robust studies on children have shown that Orthokeratology[77] and Centre Distance bifocal contact lenses[78] may arrest myopic development.
Basically, eyeglasses don't do well compared to contact lenses and other treatment methods. Finally, note that the myopia of the kids who go through this treatment gets worse, just at a slightly slower rate than other kids. So the idea that wearing reading glasses can fix myopia is still pretty silly.
On November 10 2010 03:14 mordk wrote:
I do not have a source on this, since it is just what I got taught while doing my Ophtalmology section in med school, however it should be easy to find. This is also a VERY summarized view of what I understood from refractive defects in children.
When a child has myopia (or any other refraction defect), he/she has what is called refractive or anisometric amblyopia, which, in few words, means that because one eye is giving the brain a blurred image of something, the brain "chooses" to ignore it, and make the normal eye "dominant". In the long term, this makes the visual defect in the damaged eye worse, which makes it imperative that amblyopia is treated before the age of 9, ideally before 5 years of age. This is only one type of amblyopia and milder when compared to, for example, strabism, which if untreated can have serious consequences for the strabic eye.
According to what they taught me, the way to correct anisometric amblyopia is by correcting the refractive defect with appropriate glasses, however, it IS possible that if an inappropriate corrective lens is used, and goes unnoticed for the period in which sight develops, the lens themselves become harmful to the child, but again, this would be the product of a wrong diagnosis, selection of lens.
Myopia itself however, can NEVER be permanently corrected by glasses, this is because myopia is a genetically determined condition, in which the eyeball has the "wrong shape" not allowing light beams to be projected on the retina. This won't get better or worse with glasses, it is just a thing about how the eye is, and is a different condition from amblyopia.
In conclusion, according to my university teachers, if a child has myopia, it would be correct to prevent amblyopia by wearing glasses, but this won't make the underlying defect (in this case myopia) any better or worse, and in case of older children, with their sight development complete (they do not risk amblyopia), it is only a symptomatic treatment, and doesn't have an effect on the evolution of the myopia.
I do not have a source on this, since it is just what I got taught while doing my Ophtalmology section in med school, however it should be easy to find. This is also a VERY summarized view of what I understood from refractive defects in children.
When a child has myopia (or any other refraction defect), he/she has what is called refractive or anisometric amblyopia, which, in few words, means that because one eye is giving the brain a blurred image of something, the brain "chooses" to ignore it, and make the normal eye "dominant". In the long term, this makes the visual defect in the damaged eye worse, which makes it imperative that amblyopia is treated before the age of 9, ideally before 5 years of age. This is only one type of amblyopia and milder when compared to, for example, strabism, which if untreated can have serious consequences for the strabic eye.
According to what they taught me, the way to correct anisometric amblyopia is by correcting the refractive defect with appropriate glasses, however, it IS possible that if an inappropriate corrective lens is used, and goes unnoticed for the period in which sight develops, the lens themselves become harmful to the child, but again, this would be the product of a wrong diagnosis, selection of lens.
Myopia itself however, can NEVER be permanently corrected by glasses, this is because myopia is a genetically determined condition, in which the eyeball has the "wrong shape" not allowing light beams to be projected on the retina. This won't get better or worse with glasses, it is just a thing about how the eye is, and is a different condition from amblyopia.
In conclusion, according to my university teachers, if a child has myopia, it would be correct to prevent amblyopia by wearing glasses, but this won't make the underlying defect (in this case myopia) any better or worse, and in case of older children, with their sight development complete (they do not risk amblyopia), it is only a symptomatic treatment, and doesn't have an effect on the evolution of the myopia.
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