In article <97qbf.27733$qk4.1188[at]bgtnsc05-news.ops.worldnet.att.net> ,
"Dick Adams" <bad.addr[at]nonexist.com> wrote:


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That makes no sense. How are you going to see what you are doing if you
take your glasses off?


:-)

Back when I was severely myopic, I very seldom removed my glasses. I
certainly wore them for swimming and sex.

--
Dan Abel
dabel[at]sonic.net
Petaluma, California, USA

In article <THfbf.45844$zb5.44560[at]bgtnsc04-news.ops.worldnet.att.net> ,
"Dick Adams" <bad.addr[at]nonexist.com> wrote:


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I tend not to tell people how things work when I don't have a clue.

--
Dan Abel
dabel[at]sonic.net
Petaluma, California, USA

<otisbrown[at]pa.net> wrote in message news:1131255946.163952.172090[at]o13g2000cwo.googlegroups.com...

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Seems there's more than two.

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And on the words used!

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Exactly how high would "high plus" be? Plus what? (Units??!!)
Look through "the plus" (??) at what?

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Could one say that Young's studies showed that children who
useed single-vision reading glasses with some certain positive sperical
correction (in diopters, what?) experienced myopic progression of
about a half diopter per year? Does that represent an improvement over
some worse expected rate, or what?

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You seem to be saying that Young found that bifocal eyeglasses did
not change, in the sense of becoming more concave, during the
study. (Certainly not an allusion to "muff diving".) (Well, most
people take off their eye glasses first.)

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I guess I can figure out what you mean by that. Could I assume
that, if eyes were out of balance by some fraction of a diopter, and
that, if there were any astigmatism, appropriate optical corrections
were made before the "add" was applied for reading glasses
or panes?

I would think such corrections would be appropriate, as well
as base out prism for convergence correction.

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"Plus" is a hopeless word in this context. If I could replace it with
"reading glasses" (as discussed above), perhaps we could be in agreement.
Maybe Mike even could agree?

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Good luck to anyone who would like to try atropine analogs to
help their Magoo vision. Anybody who has tried to see the road
on a sunny day on the homeward drive from a visit with a
cycloplegoid eye doctor will not rush towards the experience.

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They sell OTC reading glasses with specific values of correction,
stated in terms like +1.25D, +1.50D, etc. I got a pair for $3.98 on
sale. No base-out prisms, however, and they do not correct residual
astigmatism. But, no matter. My silicone eyes are not going to change
much anymore, and stuff at reading distance is not too hard to see
anyway, even if a bit out-of-focus on one axis or another.

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I think we could take the primate studies off the plate. A kid probably
doesn't even know what a primate is, or that he is, in fact, one.

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Guess we better get started pretty quick, while there are still some
of those left.

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If you mean that the buggers seem to be all wound up in their jargon,
I might know. But who isn't?

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Well, Otis, we have to remember that the eye guys are in business to sell
eyeglasses and stuff, and thus they are different from us, and have problems
we cannot understand, or even suspect, in some cases.

--
Dicky

Dear Dick,

Subject: The second opinion about the eye's behavior

Mike is very selective in reporting "his" studies.

The truth is that these studies consistently "conflict" -- and no
one has resolved them as yet. It does depend on the
type of question you learn to ask.

Dick Adams wrote:
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Otis> A very biased study. The "second opinion" study
run by Dr. Francis Young showed that children fitted
with a "high plus", (who were expected to look THROUGH
the plus), had the following rates (approximately).

The single-minus went "down" at a rate of -1/2 dioper per year.

The "plus" bi-focal stopped going "down".

I am not a "fan" of the bi-focal, but with this suggests
is that more agressive use of the plus BEFORE the person
is in deeper than -1/2 to -3/4 diopters could be effective
in prevention. To date, no such preventive study
has been conducted.


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Otis> MIke is right about this point -- based on the Oakley-Young
study,
if you wish to keep your distant vision clear, you are going
to have to teach youself how to consistently use the plus
for all close work. This suggests that the person
should be informed in a manner that would encourage
him to use the plus in this manner. Further, it
would appear to be a wise choice of the person
himself -- more so than a "medical" decision.


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Otis> This is the standard "drop" in your eyes for "exams" Very
unpleasant stuff -- if you ever had it. Also called a cycloplegic.
I would think that a low-cost plus would make more sense
on a scientific level.

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Otis> Rather expensive -- if you check. The
over-the-counter plus sells for about $8.


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Otis> To a certain extent -- but the person must "get the idea" and
must understand the results of the "primate" studies, which
the ODs on sci.med.vision think are a big joke.

At
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Otis> The plus (for prevention) has never been systematically
tested on a scientific basis. (i.e., undertand the meaning
of the primate studies. Thus the preventive approach
would require an "educated mind" before anything
is attempted. That fact alone would prevent
a "blind" study, and make the effort scientific
rather than "medical" -- if you know what I mean.


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Otis> Dick, I agree with you -- they seem to make "sense" to only ODs.


Otis

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"Mike Tyner" <mtyner[at]mindspring.com> wrote in message news:GI3bf.5699$AS6.837[at]newsread3.news.atl.earthlink.net...
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I do not know exactly how the tension is maintained on the lens
when the circular (ciliary) muscle is relaxed. Frankly, I do not feel too
bad about not knowing that, because I do not think I am alone in that
respect.

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I never suggested +1.25D. That seems a bit weak. Also I figured on correcting
vision at infinity then applying the "add" and whatever amount of base out prism
is consistent with the "add" chosen. To fool the eyes into thinking they are seeing
the book, or work, at infinity.

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No blur. Sharp focus at infinity with distance glasses (or naked eyes if correction
is not needed), and (same) sharp focus at working distance with reading glasses.

Kids needing some correction for distance might not want to wear eyeglasses
in public, but for reading and close working, which are solitary things, it should
be easier to persuade them.

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I am not thinking about reversing myopia, but keeping it from getting worse.
Maybe preventing it in some cases where it can be reasonably expected to
develop.

(I suspect that once the condition is reached where the images of distant objects
come to focus short of the retina, there is no going back.)

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OK. It concluded "It seems that myopic progression is connected with much
use of the eyes in reading and close work and with short reading distance but
that progression cannot be reduced by diminishing accommodation with bifocals
or by reading without spectacles."

Considering that close work is pretty definitely causative for myopia, it is
very enigmatic that fooling the eyes into thinking they are seeing at infinity
does not or would not prevent the progression or development of myopia.
Perhaps the effort of fooling those eyes was not stringent enough.

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Fooling they eyes into thinking they are seeing at infinity. How is that mixed?

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OK. Which group was that?

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information. Do you remember close-up attachments for rangefinder
cameras for decades ago? Such an attachment would put a prism over
one of the rangefinder ports so that the rangefinder could be used close up.

I think the range-finder camera model is more generally useful. Consider the
difficulty involved in superimposing two images, as would be necessary to
obtain distance information, if one image could not be sharply focused.
For eyes, then, one best starts with corrected, balanced, vision. That is
to say, each eye, relaxed, sees the same sharply focused image at infinity.

I can imagine there would be a lot of eyeball consternation if the eyes needed
to bring together two images which could not be superimposed. Even, I would
guess that such continual crisis could lead to myopia and other evil conditions.

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Several of those words are not in my dictionary. Doubtful if I could diagram
the sentence even if I knew the meanings of the words.

Hey, why don't we start on "blur"? What exactly does that mean?

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The idea of using one eye as a control on the other upset me. Keeping eyes
balanced, if there is an option, would seem a kinder goal.

--
Dicky

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"Dick Adams" <bad.addr[at]nonexist.com> wrote

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You're saying myopia is caused by the zonular fibers?

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If you mean putting Walgreen +125's on a group of emmetropes or myopes, no.

If you mean making young myopes wear glasses that are +075 blurry far away,
yes.

They got worse _faster_ and ethical guidelines forced the experimenters to
remove the +075 and shut down their experiment.

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It isn't practical or humane to blur distance vision in students when your
study extends over two or three school years.

Single-vision reading glasses would be appropriate for a group of emmetropic
children, but three-quarters of them will never get myopia and COMET isn't
targeted at _preventing_ myopia.

Their kids already _have_ myopia and the purpose is to test a practical
treatment in practical circumstances.

For another look at practical treatments, see the abstract I pasted at
bottom.

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You may have something, but you're mixing variables, as you criticize below.

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They don't make sense to me either. What makes sense is "THIS group got less
nearsighted than THAT group."

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Like correcting accommodation and convergence simultaneously.

FWIW, the bifocal results, if verifiable, only seem to work when vergence
maintains an eso fixation disparity.

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So you agree that some treatments (and some experiments) are too intrusive
to be practical.

-MT

**************************************
Br J Ophthalmol 1989 Jul;73(7):547-51
Effect of spectacle use and accommodation on myopic progression: final
results of a three-year randomised clinical trial among schoolchildren.
Parssinen O, Hemminki E, Klemetti A.
Department of Ophthalmology, Central Hospital of Central Finland, Jyvaskyla.

Two hundred and forty mildly myopic schoolchildren aged 9-11 years were
randomly allocated to three treatment groups and the progression of myopia
was followed-up for three years. The treatment groups were: (1) minus lenses
with full correction for continuous use (the reference group), (2) minus
lenses with full correction to be used for distant vision only, and (3)
bifocal lenses with +1.75 D addition. Three-year refraction values were
received from 237 children. The differences in the increases of the
spherical equivalents were not statistically significant in the right eye,
but in the left eye the change in the distant use group was significantly
higher (-1.87 D) than in the continuous use group (-1.46 D) (p = 0.02,
Student's t test). There were no differences between the groups in regard to
school achievement, accidents, or satisfaction with glasses. In all three
groups the more the daily close work done by the children the faster was the
rate of myopic progression (right eye: r = 0.253, p = 0.0001, left eye: r =
0.267, p = 0.0001). Myopic progression did not correlate positively with
accommodation, but the shorter the average reading distance of the follow-up
time the faster was the myopic progression (right eye: r = 0.222, p =
0.0001, left eye: r = 0.255, p = 0.001). It seems that myopic progression is
connected with much use of the eyes in reading and close work and with short
reading distance but that progression cannot be reduced by diminishing
accommodation with bifocals or by reading without spectacles.

"Mike Tyner" <mtyner[at]mindspring.com> wrote in message news:cDSaf.4989$m81.958[at]newsread1.news.atl.earthlink.net...

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Well, I am still betting on fragility of the cartilaginous elements which support
the "crystalline" lens. (It is hardly crystalline, you know!)

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Well, maybe. But it is a medication, to be taken over a long period of
time. Bias may be suspected if such agents are promoted by their
manufacturers. Likewise, professional lethargy may contribute to
the overprescription (and inappropriate prescription) of medications.

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Studies seem gimmicky. Why, for instance, are the COMET trials based on
progressive addition lenses? Wouldn't single-vision reading glasses, under
carefully controlled conditions, be more appropriate? (Remember, I am calling
for a convergence adjustment as well as for plus and for and astigmatism correction).
And, in this vein, I doubt if bifocal contacts, whatever in blazes they may be, can
make any sense at all.

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Some things clearly do not make sense. Like lumping a lot of stuff in an experimental
therapy. If something works, you might never know what, and if it doesn't work, you
would not know if some single element alone would have been effective.

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I would not want that done on any child of mine.

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Fuckin' "A"!!! And for any one who is subsidized or entertained by a
manufacturer.

--
Dicky

P.S. It is all pretty academic with me, since I see now through silicone, and
my severely myopic "one-eyed" child is supported by a husband. But this may
be of interest: After my implants, my wife read about accommodating implants.
Well, I had not been told about that possibility. Good thing, too, because I
might have been dumb enough to try it.

-d
(seeing my screen very clearly through +1.25 Walgreens readers)

"Dick Adams" <bad.addr[at]nonexist.com> wrote

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So by the time humans start wearing glasses, the plasticity seen in neonatal
animal studies doesn't hold. If it did, plus lenses would slow myopia.

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Not likely. It acts on growth-regulating receptors in the sclera. It isn't
likely you could get the same effect with orals except with fatal doses.

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Yes, it's been tried several ways. The COMET group is soliciting patients
now for a new trial.

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It's best not to rely on what "makes sense." I don't think bifocal contacts
are that promising, but I can't ignore Tom Aller's findings - after fitting
young myopes with a bifocal contact lens in one eye and a single-vision
contact in the other, he found the bifocal eyes consistently got less
nearsighted. I'm not recommending it yet, but I'm interested to see if the
effect can be replicated independently. Anytime somebody patents a
procedure, like Dr. Aller did, you have to watch out for proprietary
interests.

-MT

"Mike Tyner" <mtyner[at]mindspring.com> wrote in message news:lePaf.4882$m81.4286[at]newsread1.news.atl.earthlink.net...

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What glasses? Under what conditions? How well controlled?

Yeah, yeah, I know, you tried the plus lens trick and it did not
work. I tried too -- good for burning ants on the sidewalk when
you are a kid.

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Everything fades away pretty quick when you are over 95. So what?

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Can it be made into a pill? Pills, and any medicines, I guess, which you
keep taking forever, are highly regarded by the pharmaceutical companies.

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Bifocal contacts?

Has anybody responsibly tried reading glasses for myopia candidates. At
the age where that might be effective, it is doubtful the subjects could manage
contacts of any kind.

Bifocal contacts do not make any sense at all to me, for anybody, much less
kids.

--
Dicky

<nicoleh76[at]gmail.com> wrote

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Stop having birthdays?

Usually myopia increases for a while, then slows and stops changing.

Your doctor will say there's little you can do to alter that pattern.

"Don't read too close" and "Don't read without breaks" are about the only
advice supported by evidence.

Wearing glasses, not wearing glasses, wearing special glasses, all make very
little difference.

The internet is full of contrary opinions, and exceptions do exist. Near
birth, the human eye is probably VERY responsive. By age 9 or 10, when most
nearsightedness begins, eyeballs don't change much in response to wearing
lenses, because groups wearing glasses get no more nearsighted than groups
who don't. That finding is important because it applies to humans. Lots of
studies show that neonatal animal eyes can be influenced by lenses, but they
also show an age where the response fades away.

There's some indication that an atropine analog called pirenzepine may be
used effectively to limit myopia. And there have been some promising results
recently with bifocal contacts in certain subgroups.

But I don't think you should waste much energy worrying about what you can
do to alter the natural history of your myopia. It's mostly genetic.

-MT