I recently asked my optomistrist what the causes of myopia were. However, she
answered with an abrupt "genetics". Is it possible that genetics are not the
sole cause/contributor of myopia?
14
Jan
myopia causes
gp…@gems.vcu.edu wrote:
>I recently asked my optomistrist what the causes of myopia were. However, she
>answered with an abrupt "genetics". Is it possible that genetics are not the
>sole cause/contributor of myopia?
Your optometrist is apparently not up on both the developmental
and scientific communities’ studies. The continuous near point
focusing required when a person (and studies have shown the same
for animals) looks at close objects, such as reading, computer
screens, etc. (in other words…environmental factors) appear to
be the major cause of myopia and the major cause of the increased
myopia, once it begins. There are many ways to try to prevent
myopia from beginning and, if it does begin, to try to slow down
or stop the progression of the myopia. Counter-stress lenses to
be worn while the person is doing near-area seeing for any
extended period (the lenses necessary would be determined by
appropriate evaluation at the distances in question to determine
if the person could benefit from their use, and if so, which
powers would be optimum). In addition, orthokeratology (by a
practitioner who is knowledgeable… certified by the National
Eye Rasearch Foundation… are who I would contact). You notice
I mention IN ADDITION…orthokeratology without paying attention
to the environmental aspects and the developmental aspects will
have a lower long-term effect.
Myopia is not a "natural" occurrance, but rather a response of
the organism to the environmental demands on the visual system.
Of course there are examples of myopia being present at or soon
after birth…but the over-welming causes of myopia is
environmental.
Paul Planer,O.D.
I wish the cause of my myopia was environmental, but I can say with
absolute certainty that it is genetic. I can say it stems from my
mother’s side of the family; at one time I was able to see with my
grandmother’s glasses as well as my own (even our lef eye was slightly
weaker than our right eye).
What I find interesting about bad eyesight is how prevalent it is; if you
subscribe to the theory of natural selection myopia at the very least
should have disappeared long ago. Afterall, if you can’t see what’s
coming you can’t get out of its way. Primitive societies must have
protected those not blessed with 20/20 vision.
I will agree that environmental stress (UV rays, smog, weather,
atmospheric pressure, etc.) can degrade a person’s vision, but by how
much? What about farsightedness? Presbyopia? Is bad eyesight universal
or do some cultures/races appear to be blessed with good vision/bad
vision?
Currently I see just as well with a 6.0 contact lens as I did with my 6.5
glasses. I even saw okay with a 5.75 contact lens, but I don’t take this
to mean my eye is getting better with age although my optomitrist did tell
me once that it is possible for myopia to lessen as a person gets older
and in some rare cases even go away (maybe 20/30 to 20/20), but this is
because we tend to shrink as we age and we all know that myopia is caused
by an overlong eyeball.
Of course, I’d have to live 200 years before my eye shrunk that much
Fred
"paul m. planer" <papla…@atl.mindspring.com> wrote:
>Your optometrist is apparently not up on both the developmental
>and scientific communities’ studies. The continuous near point
>focusing [...] Counter-stress lenses [...]
>over-welming causes of myopia is environmental.
>Paul Planer,O.D.
Where are you located, Dr. Planer? I may have friends in your area to
refer to you.
Stefan Stefanov
Atlanta, Georgia. Any optometrist who practices developmentally
and functionally should think as I do.
Paul Planer,O.D.
gurze…@aol.com (Gurzeler) wrote:
>I wish the cause of my myopia was environmental, but I can say with
>absolute certainty that it is genetic.
The predisposition may have a genetic component, but the
environmental demands is the main culprit. People and animals
placed in a near-point environment will show myopia shift due to
the stress of this near-point world in the vast majority of
cases. The astronaunts show myopic shift in their visual systems
when back from space. Animals, when forced to accommodate
(focus) will show myopic changes in their visual systems. If
myopia were caused by genetics alone, none of the above would
happen. One of the main causes of a person’s myopic increase, I
feel, is the practitioner advising the patient who is myopic to
read with the same power glasses that were prescribed for
distance vision. This would necessitate the patient to again
make a focus change for the excess power in the glasses designed
for distance when reading….this would tend to cause the myopia
to increase as a response..thus reducing the required focus
effort…but leaving the patient in a more myopic state. A
person should only utilize that power necessary for the distance
focused upon..sometimes this means to remove glasses for reading,
or wear a bifocal or less power whenever sustained near-point
reading/focusing is required.
>What I find interesting about bad eyesight is how prevalent it is; if you
>subscribe to the theory of natural selection myopia at the very least
>should have disappeared long ago. Afterall, if you can’t see what’s
>coming you can’t get out of its way. Primitive societies must have
>protected those not blessed with 20/20 vision.
Primative societies, and societies not doing the near area
focusing that occurs in a technologically advanced society such
as ours, did not develope myopia to any real degree at all.
There was no need for the people to develope myopia…what
purpose is myopia to the organization except to reduce the
requirement of focusing at the near area. Our bodies do not, for
the most part, make changes for no reason….Animals and all
living things make changes, usually as a response to a stress.
Our muscular system makes changes to the stress of lifting
weights by structural changes. Without the stress of gravity,
the muscular system will break down. Our visual system will have
a strong tendancy for change due to the stress of sustained
near-area focusing. One of the prevelent paths of change is to
become myopic. Another of the changes is to limit the amount of
sustained focusing the system can do….you’ll see many people
who, after reading for a few minutes, have the letters get
blurred, jumpy, etc…There are other responses to change the
visual system can make, but myopia is the more prevelant one.
>I will agree that environmental stress (UV rays, smog, weather,
>atmospheric pressure, etc.) can degrade a person’s vision, but by how
>much? What about farsightedness? Presbyopia?
You’re now talking about medically caused problems, by talking
about UV rays, etc. Humans generally start out farsighted
(hyperopic) which tends to lessen as more and more near focusing
is done. Presbyopia is caused mainly by a hardening of the
crystilline lens behind the pupil…may be some other causes,
also, here.
Is bad eyesight universal
>or do some cultures/races appear to be blessed with good vision/bad
>vision?
Some cultures do not do much near-area reading/looking/focusing.
>Currently I see just as well with a 6.0 contact lens as I did with my 6.5
>glasses. I even saw okay with a 5.75 contact lens, but I don’t take this
>to mean my eye is getting better with age although my optomitrist did tell
>me once that it is possible for myopia to lessen as a person gets older
>and in some rare cases even go away (maybe 20/30 to 20/20), but this is
>because we tend to shrink as we age and we all know that myopia is caused
>by an overlong eyeball.
Not really…it can be there because the front surface of the eye
is curved more than the optics of the eye can handle. When a
child reads, the pressures inside the eye increases…can this be
a push to increase the curvature of the cornea or lenghten the
eye ball? When a person reads, the curvatures of the front of
the eye changes…can this be a push to have the curvatures
increase in shape?….No one knows the answers to all the
questions about myopia….but the scientific community does
recognize the stresses of environmental demands to be one of the
main precipitating factors in the cause of myopia.
>Of course, I’d have to live 200 years before my eye shrunk that much
True…unfortunately…the chances of your changing back to
20/30, or anyway near it is slim to none. One thing you can do
is to be evaluated by a developmental/functional eye care
practitioner (usually found in the optometric profession)…you
will probably be told not to wear your -6D power for reading. You
would not want to increase in power over what you have in the
future.
>Fred
Hope this gives you some food for thought.
Paul Planer,O.D.
"paul m. planer" <papla…@atl.mindspring.com> wrote:
>Atlanta, Georgia. Any optometrist who practices developmentally
>and functionally should think as I do.
Jawohl, mein Herr!
Ray
"paul m. planer" <papla…@atl.mindspring.com> wrote:
…………………
>I will agree that environmental stress (UV rays, smog, weather,
>>atmospheric pressure, etc.) can degrade a person’s vision, but by how
>>much? What about farsightedness? Presbyopia?
>You’re now talking about medically caused problems, by talking
>about UV rays, etc.
How would you distinguish a "medically caused problem" from whatever
else? In any case, my idea of a "medically caused problem" is an
iatrogenic one.
>Humans generally start out farsighted
>(hyperopic) which tends to lessen as more and more near focusing
>is done.
But, in one with no myopic tendency (the preponderant case), is there
really any lessening of hyperopia due to focusing–rather than just
due to normal ontogenetic development, and later, tissue aging?
>Presbyopia is caused mainly by a hardening of the
>crystilline lens behind the pupil…may be some other causes,
>also, here.
> Is bad eyesight universal
>>or do some cultures/races appear to be blessed with good vision/bad
>>vision?
>Some cultures do not do much near-area reading/looking/focusing.
More determinatively, the eyes of different *races* have different
norms for various attributes/functions (whether that be politically
correct or not).
- Hide quoted text — Show quoted text -
>>Currently I see just as well with a 6.0 contact lens as I did with my 6.5
>>glasses. I even saw okay with a 5.75 contact lens, but I don’t take this
>>to mean my eye is getting better with age although my optomitrist did tell
>>me once that it is possible for myopia to lessen as a person gets older
>>and in some rare cases even go away (maybe 20/30 to 20/20), but this is
>>because we tend to shrink as we age and we all know that myopia is caused
>>by an overlong eyeball.
>Not really…it can be there because the front surface of the eye
>is curved more than the optics of the eye can handle. When a
>child reads, the pressures inside the eye increases…can this be
>a push to increase the curvature of the cornea or lenghten the
>eye ball? When a person reads, the curvatures of the front of
>the eye changes…can this be a push to have the curvatures
>increase in shape?….No one knows the answers to all the
>questions about myopia….but the scientific community does
>recognize the stresses of environmental demands to be one of the
>main precipitating factors in the cause of myopia.
I wouldn’t think one could say there is any *scientific community* as
to this point.
Ray
Very well said, Dr. Planer! I have nothing but praise for your post
(sorry for not quoting it but its firly long and appears twice anyway). I
only wish the rest of the OD and opthal community adopts these views soon
(or ever, in the worst case scenario).
I agree with virtually everything you say, if you have been around on
this group you may have noticed that I have repeatedly made the same
points. I have two sets of questions for you.
1) You point out that increase in myopia is caused by prolonged near work
when distance correction (or bare emmetropic eye) is used. The eye adapts
to the environmental demands (induced hyperopic defocus in this case).
Couldn’t the adult eye adapt to the opposite case, myopic defocus,
thereby causing the eye to shift in a hyperopic direction, possibly thru
reduction in axial length. This has been demonstrated in young monkeys.
For many years I had assumed that Myopia St is one way – up the hill. It
can be prevented but not reduced. But for the last several years, as the
Internet brought many people with same interests instantly together, I
have seen many cases of reduced myopia (self-reported), mainly thru the
wearing of (relative) plus lenses. I currently think that some amount of
myopia reduction is possible, an average of 1.5-2 D, but complete
reversal for the higher ranges is hard to imagine. What is your stance on
this?
2) Do you prescribe bifocal or progressive glasses to pre-presbyopic
myopes? How effective do you think these glasses are in combatting
myopia? Which would be easier to adapt to?
Finally, a brief mention of one of the dogmas of the OD profession:
*myopia stabilizes at some point in time*, usually in the mid-20s. Only
Paul Harris and myself have said here that myopia can progress well until
into someone’s 40s, or in a more relaxed parlor, indefinitely. This has
been documented in the recent study "Longitudinal Stability of Refractive
Error in an Adult Patient Population" by R Payor et al (
http://www.aaopt.org/DBscripts/Abs95/OR-306 ). A related study, A
longitudinal study of myopic development in a young adult population.
Preliminary findings. can be found at
http://www.aaopt.org/DBscripts/Abs95/BV-319 .
It strikes me though, that while I try to wear correction that is
suitable for the work I do in terms of distance and have the side and
nasty problems of not being able to see clearly across the office, many
of my colleagues wear normal distance correction all day long in front of
a computer and do fine nonetheless. This is where, I guess, psychology
plays a role. I am conscious of the harmful effects of prolonged near
work and feel visually uncomfortable if I wear a distance correction for
close work. On the contrary, many of these people haven’t heard the word
‘diopter’, let alone be "initiated" in the visual process. Maybe the
answer is to "harden" a little bit. So I am left wondering on this point
as well, and would appreciate your comment.
Regards,
Stefan Stefanov
ra…@sirius.com (Raymond A. Chamberlin) wrote:
>"paul m. planer" <papla…@atl.mindspring.com> wrote:
>>Atlanta, Georgia. Any optometrist who practices developmentally
>>and functionally should think as I do.
>Jawohl, mein Herr!
>Ray
I HATE to admit, but the same thought crossed my mind after reading
Paul’s Post.
John Warren, OD
http://www.execpc.com/~warren
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