> > I don't know what "stresses" you mean. If "stress" is accommodation,
then
> > there are lots of people who carry around a huge load of habitual
> > accommodation and they aren't more prone to nearsightedness. If
"stress" is
> > something else then please be more specific.

> The uncorrected or undercorrected hyperopes (farsighted) are that group
> of constantly stressed (at least accomodation -wise) people.

> I don't know what "stresses" you mean. If "stress" is accommodation, then
> there are lots of people who carry around a huge load of habitual
> accommodation and they aren't more prone to nearsightedness. If "stress" is
> something else then please be more specific.

> > In Russia, I understand that learning to read is
> > delayed from 1-3 years. For this reason and they see less
> > nearsightedness accordingly.
> We agree that myopia is associated with more time spent reading. Myopia is
> an adaptive response to near work. But easing accommodation with special
> lenses does not significantly alter that correlation.

> > This is what I was taught and how I have apporached this problem for
> > over 30 years with my patients. When you are right 9/10 of the time,
> > it is hard to chuck it all and start thinking exclusively genetics.
> Makes one wonder why the effect doesn't show up in controlled studies.
> -MT

> WHile I do not dispute the work of these learned researchers, I have a
> hard time with the "genetic predisposition" aspect of this. While
> certain types of high refractice error of all types has been shown to
> be hereditary, vision, being a learned response, changes with the
> amount of stress the visual system can handle.
> Without trying to be racist or bigoted, we see a alot of high myopia in
> the asian populations. These people, as a whole, have different view
> of education and instill in their children the need to strive for
> excellence. The Indian culture (from India) is much the same way in
> the educated segment of their population.

> Once you use up your ability to absorb visual stress (i.e. reading and
> CRT use) after doing this task for hours at a time, your ciliary muscle
> 'cramps up' causing a blur at far which initially clears, but later can
> become permanent by causing elongation of the eyeball which is, by
> definition, myopia.

> This is why so many functionally/developmentally
> trained optometrists apply reading lenses to young people. In some
> cases, the child's eye is not ready to absorb these kinds of stresses
> at such an early age. In Russia, I understand that learning to read is
> delayed from 1-3 years. For this reason and they see less
> nearsightedness accordingly.
> This is what I was taught and how I have apporached this problem for
> over 30 years with my patients. When you are right 9/10 of the time,
> it is hard to chuck it all and start thinking exclusively genetics.
> --Dr. Tom
> retinula[at]hotmail.com wrote:
> > Hello all,
> > here is an interesting and highly speculative article that I was
> > alerted to by dr. judy. I believe someone posting here a month or two
> > ago gave reference to this theory but a link was never posted.
> > > perhaps, after reading this, many of the people who are so frustrated
> > about their myopia might consider it in a different light.
> > > retinula
> > > ============
> > > W. Mak, M.W.M. Kwan, T.S. Cheng, K.H. Chan, R.T.F. Cheung and S.L. Ho
> > Department of Medicine, Queen Mary Hospital, University of Hong Kong,
> > 4/F, Professorial Block, 102 Pokfulam Road, Hong Kong, PR China
> > > Medical Hypotheses 2006 vol. 66(6) Pages 1209-1215
> > > Myopia as a latent phenotype of a pleiotropic gene positively selected
> > for facilitating neurocognitive development, and the effects of
> > environmental factors in its expression
> > > Myopia has become an almost pandemic problem in many populations.
> > There are compelling evidence to suggest that myopia is a hereditary
> > condition. However, myopia would constitute a definite selection
> > disadvantage during most stages of human evolution, which is
> > incompatible with its moderate to high prevalence in most modern
> > populations. The rapid upsurge of myopia over just a few decades also
> > implies that its inheritance does not follow any of the usual
> > patterns, and environmental factors may have an important role in
> > precipitating its occurrence in those who are genetically predisposed.
> > Previous studies showed that myopes were, on average, more intelligent
> > than non-myopes, and this association had been attributed to a
> > biological link between eye growth and brain development. We propose a
> > pleiotropic genetic model to explain the atypical epidemiologic and
> > inheritance pattern of myopia and its relationship with neurocognitive
> > development. This pleiotropic gene was positively selected for its
> > facilitation of human intelligence. The myopic component is a latent
> > phenotype; myopia will not be expressed unless some novel external
> > factors are encountered (i.e. a "quirk" phenomenon). Therefore, the
> > myopic component was selectively neutral in our ancestral environment.
> > The net gain in Darwinian fitness enables the pleiotropic gene to
> > attain a high frequency in the human population, as reflected by our
> > current prevalence of myopia.
> > > Shortened Link:
> > http://tinyurl.com/kusft

> vision, being a learned response, changes with the
> amount of stress the visual system can handle.

> Without trying to be racist or bigoted,
> we see a alot of high myopia in
> the asian populations. These people, as a
> whole, have different view
> of education and instill in their children
> the need to strive for
> excellence. The Indian culture (from India)
> is much the same way in
> the educated segment of their population.

> Once you use up your ability to absorb
> visual stress (i.e. reading and
> CRT use) after doing this task for hours
> at a time, your ciliary muscle
> 'cramps up' causing a blur at far which
> initially clears, but later can
> become permanent by causing elongation
> of the eyeball which is, by
> definition, myopia.

> This is why so many functionally/developmentally
> trained optometrists apply reading lenses to young people.

> In some cases, the child's eye is not ready to
> absorb these kinds of stresses
> at such an early age.

> In Russia, I understand that learning to read is
> delayed from 1-3 years. For this reason and they see less
> nearsightedness accordingly.

> This is what I was taught and how I have apporached this problem for
> over 30 years with my patients. When you are right 9/10 of the time,
> it is hard to chuck it all and start thinking exclusively genetics.

> Hello all,
> here is an interesting and highly speculative article that I was
> alerted to by dr. judy. I believe someone posting here a month or two
> ago gave reference to this theory but a link was never posted.
> perhaps, after reading this, many of the people who are so frustrated
> about their myopia might consider it in a different light.
> retinula
> ============
> W. Mak, M.W.M. Kwan, T.S. Cheng, K.H. Chan, R.T.F. Cheung and S.L. Ho
> Department of Medicine, Queen Mary Hospital, University of Hong Kong,
> 4/F, Professorial Block, 102 Pokfulam Road, Hong Kong, PR China
> Medical Hypotheses 2006 vol. 66(6) Pages 1209-1215
> Myopia as a latent phenotype of a pleiotropic gene positively selected
> for facilitating neurocognitive development, and the effects of
> environmental factors in its expression
> Myopia has become an almost pandemic problem in many populations.
> There are compelling evidence to suggest that myopia is a hereditary
> condition. However, myopia would constitute a definite selection
> disadvantage during most stages of human evolution, which is
> incompatible with its moderate to high prevalence in most modern
> populations. The rapid upsurge of myopia over just a few decades also
> implies that its inheritance does not follow any of the usual
> patterns, and environmental factors may have an important role in
> precipitating its occurrence in those who are genetically predisposed.
> Previous studies showed that myopes were, on average, more intelligent
> than non-myopes, and this association had been attributed to a
> biological link between eye growth and brain development. We propose a
> pleiotropic genetic model to explain the atypical epidemiologic and
> inheritance pattern of myopia and its relationship with neurocognitive
> development. This pleiotropic gene was positively selected for its
> facilitation of human intelligence. The myopic component is a latent
> phenotype; myopia will not be expressed unless some novel external
> factors are encountered (i.e. a "quirk" phenomenon). Therefore, the
> myopic component was selectively neutral in our ancestral environment.
> The net gain in Darwinian fitness enables the pleiotropic gene to
> attain a high frequency in the human population, as reflected by our
> current prevalence of myopia.
> Shortened Link:
> http://tinyurl.com/kusft