RM asks the wrong questions -- and always ingores the correct answers.

Discussion in 'Optometry Archives' started by Otis Brown, Nov 15, 2004.

  1. Otis Brown

    Otis Brown Guest

    Not.txt

    Subject: Re: Challenging questions that Otis can't answer

    Dear Optomterist RM,

    My, that's presumptuous!

    Since you have already stated that I "can't answer" you are
    obviously profondly biased by that specific satement.

    I assume that:

    1. You will not let me answer, or

    2. You will totally IGNORE any answer I provide about
    the behavior of the natural eye as a control-system.

    However, thanks for your thougtful questions.

    I will forward them to the scientist Dr. Colgate as well as
    other engineers interested in true-prevention.

    Remember that Donders-Helmholtz is a THEORY where you ASSUME
    that it is FROZEN (as in box-camera).

    It is this assumption that has failed. Any good engineer can
    optically analyize a box-camera. The calculations can be carried
    out to three, four and five significant figures. But when you are
    all done -- you have proven nothing.

    The answers you get depends on the type of questions YOU
    LEARN TO ASK.

    And the issues (and questions) I ask have to do with the
    fundamental question of the dynamic behavior of the natural eye
    (as an entity).

    But, I will review your summarized statement that assumes the
    Donders-Helmholtz theory concerning the eye.


    Best,

    Otis

    Engineer

    ____________



    RM > Questions for Otis:


    RM > 1. What physical structures within the eye are changed by
    using plus lens therapy on an anatomical myope (e.g. myopia
    caused by increased axial length of the eye or increased
    curvature of the cornea)?

    Otis> The concept of "length" is an extrapolation of the
    measurement of a refractive-state. To calculate a "length"
    you must assume a frozen box-camera.

    RM > To state it another way, exactly what is it that plus lenses
    do that causes the visual image to be brought to focus on
    the retina of a myope?

    Otis> Assuming a refractive-state of -1/2 diopter, then the
    accommodation system will maintain sharp focus up to -1/2
    diopter. The natural eye can be made to change its
    refractive status from a postive value to -1/2 diopter by

    Otis> a. A strong minus lens. Thus this reafractive state in not
    open to box-camera analysis. It CAN BE a temporary state,
    and provided that the visual environment is all moved out to
    "infininty", the same process that created the negative
    refractive state, can be relied on to produce gradual
    clearing -- it the person has the persistance to use the
    plus correctly.

    Otis> b. Again, your mistake is to ASSUME a box-camera analysis
    -- which is a conceptual error in the first place.

    RM > What anatomic structures within the eye are changed to
    achieve this?

    Otis> a. I only report what is actually measured (on an
    input-output) basis. You are asking for spculation.

    RM > Do you propose that the length of the eye shortens?

    Otis> a. No. It is obvious that when you place a minus lens on
    the natural eye, and the refractive status of this natural
    eye changes in a negative direction that one, several or
    several refractive items MUST CHANGED. The important fact
    is the truth of direct change (as a sophisticated control
    system) and not be concerned about which -- of several --
    components were necessarily chaned to achieve the above
    stated factual result.

    RM > Do you propose that the curvature of the cornea flattens? Do
    you propose that the index of refraction of ocular tissues
    is decreased?

    Otis> a. I am only concerned that when you apply a step-function
    INPUT to this sophisticated system, that the natural eye
    changes its refractive state following the e ^ (-t/TAU)
    function. I you stating that this does not happen, and this
    result is not repeatable?

    RM > 2. How can you be so opposed to minus lenses for myopia
    treatment yet be unopposed to the use of LASIK surgery?

    Otis> a. That is not what I said. A person has the right of
    informed choice. I am never going to stand in a person way
    -- what ever his choice. Once you start wearing the minus
    lens, the concept of true-prevention is moot. If a person
    is at -6 diopters, the Lasik, or whatever is a matter of
    that persons choice. I am not "opposed" to the use of a
    minus lens either -- if that be the person's choice.

    RM > In LASIK surgery you are simply removing plus power from the
    cornea by flattening it's curvature (equivalent to adding
    minus lens power) so as to get the visual image to focus on
    the retina?

    Otis> a. Assuming a box-camera "picture" then the analysis is
    correct.

    RM > 3. Explain how it is that plus lens therapy works for only
    younger patients but not for older ones?

    Otis> a. I NEVER use the word "therapy". And as far at "works" I
    say that the person himself must see the results. This
    requires a strong will in the person, since true-prevention
    is never easy. Further the person is not a "patient". I
    expect that he must have the insight of an engineer to work
    this issue correctly. Therefore the person would have to be
    old enough to understand the issues, and the effort it will
    take to achieve the desired result. No, you can never
    "prescribe" the plus for prevention.

    RM> Do you think that the decreased effectiveness of plus lens
    treatment for myopes correlates with the onset of
    presbyopia?

    Otis> a. As most of these ODs on sci.med.vision have stated, the
    plus or minus lens has NO EFFECT on the refractive state of
    the eye. I agree that prevention with the plus MUST START
    BEFORE a minus lens is used. The issue is whether the
    person himself is effective in clearing his vision to pass
    the DMV requirement -- and thus avoid any use of the minus
    lens.

    b. Do not confuse "old age" vision situations with
    true-prevention for a young pilot. An individual at 20/50,
    who wishes to clear to the required standard (and a
    refractiv state of zero) is not concerned about his
    refractive status at age 65.

    RM > Doesn't this observation support the notion that plus lens
    therapy is simply just helping the subpopulation of myopes
    that have an accommodative component to their refractive
    error?

    Otis> a. I do not use the term "therapy". Further I do not use
    the term "refractive error".

    RM> What about anatomical myopes?

    Otis> a. If you place a strong minus 6 D lens on a population of
    young eyes, and they go "down" to -4 diopters -- then YOU
    tell me -- are they "anatomical myopes" or regular "myopes"
    or accommodation myopies or what, or are they "minus lens"
    myopes?

    RM > How do you propose we treat anatomical myopes who apparently,
    by your own experience, aren't candidates for plus therapy?

    Otis> a. I do not propose you do anything. In fact, the
    preventive effort is proposed for an engineer-pilot himself
    -- should he be interested in "protecting" his distant
    vision through four years of college. Obviously this is his
    choice -- and certainly not your choice or decision at this
    point.

    RM > 4. Explain exactly what the "devastating effects" of minus
    lens treatment are for myopes-- and I don't mean
    OVERMINUSING them.

    Otis> a. The point of intelligent "Shawn's" work in clearin his
    vision to 20/20 is to AVOID the use of a -1.5 diopter lens
    -- thus avoiding the devasting effects of stair-case myopia.
    The effects result in the percentage of detached retinas
    that develop in higher levels of myopia. (Perkins study --
    "Morbity from Myopia) An ounce of prevention is worth a ton
    of "cure".

    Otis> b. Again you totally miss my point. You determine if the
    natrual eyes refractive state "follows" the applied minus
    lens to PROVE a dynamic system -- on an "input" versus
    "output" basis. Once an engineer reviews this OBJECTIVE,
    REPEATABLE, SCIENTIFIC data, then the intelligenct, highly
    motivated pilot can make the decision to agressively use the
    plus to clear his distant vision. That is by his judgment
    -- not by YOUR judgment.

    RM > I mean simply giving them just enough minus lens power to
    focus the visual image on the retina?

    Otis> a. If the pilot is passing the required Snellen-DMV test,
    then there is no requirement for wearing a minus lens, i.e.,
    20/40 vision. It is true there will be SLIGHT blur -- but
    not enough to fail that DMV test. The goal for the pilot
    then is to clear his distant vision, by optically moving all
    "near" objects to "infinfinity" with a strong plus for all
    close work. If the pilot is persistant, then the prediction
    is that he can clear his distant vision in from six to nine
    months.

    RM > Explain what the devastating effects are at an
    anatomical/physiological/biochemical level.

    Otis> a. I think that the Perkins study is clear enough.
    Nearsighedness is something you should wish to avoid for
    that reason.

    Otis> b. Using you assumed box-camera model I suppose. The
    purpose of true prevention is to AVOID getting into
    nearsightedness and thus AVOID these effects. You seem to
    miss that point.

    RM > What structures within the eye are changed by the minus lens?

    Otis> It is sufficient to know that the natural eye moves from a
    positive refractive state to a negative refractive state --
    as a control system. Analysis of how the natural eye
    achieves this result can be determined by future research
    and analysis. The point is that the natural eye is proven
    to do this.


    RM > Answer these questions Otis. Don't give us any more one-rat
    studies or case reports.

    Otis> a. Would you accept a two-rat study?

    Otis> b. You are not going to dictate conditions my friend. If
    you don't like the experimental data that demonstates that
    the natural eye's refractive status follow's its applied
    visual environment - just say so. If you want to
    "quick-fix" the public with a minus lens, and ignore the
    stair-case myopia that develops, then you can continue to
    say it is there "genetics".

    RM > Don't sight any old texts or drop the names of famous old
    optometrists.

    Otis> a. I am not certain which "old texts" I should ignore -- on
    your order. Which ones? Introduction to Physiological
    Optics? Control Theory? Scientific publications by Dr.
    Francis Young? Which names should I "not drop". You tell
    me. What, you don't like famous "old" optometrists who are
    now working for a person's right to a second-opinion? That
    is hardly even professonal on your part. Are you going to
    give me a list of the "right" optometrists? I wonder.

    Otis> b. And I assume that you are going to require that I ignore
    all scientific studies where you don't like the results. I
    have been down that road with other biased optometrists.


    Otis> c. You have the bad habit of wishing to dictate conditions.
    Sorry, I don't agree with you. I pay attention to
    scientific facts concerning the dynamic nature of the
    primate eye -- and you do not. Why should I listen to you?

    RM > Just try to explain it on a truly scientific level.

    Otis> a. It depends on what you mean by "a truly scientific
    level". You probably mean explain on a "box-camera" level.
    You can use a ray-trace computer to do that.

    Otis> b. Given DrJudy's statement that she was going to ignore
    all experimental data taken from animals -- I assume you are
    going to do EXACETLY THE SAME THING.

    Otis> c. You exclude any an all scientific data you don't like,
    or don't like the implication of the experimental data.
    That may be "optometry" but is certainly is not science. It
    is simple bias with tunnel vision my friend.

    Best,

    Otis Engineer

    RM
     
    Otis Brown, Nov 15, 2004
    #1
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  2. Otis Brown

    RM Guest

    No Otis, we have been waiting for you to provide a cogent understandable
    explanation for the effects that you claim your plus lens treatment has.
    You provide none. You just keep repeating that it DOES work and that we are
    fools and conspirators for not seeing it your way. I want to understand
    the nuts and bolts of how it works given the known anatomy and physiology of
    the eye. The eye is not an equation Otis. Perhaps I will coin that term as
    you like to coin the "box camera" phrase. The eye is constituted of
    collagen, muscle fibers, nerve cells, blood vessels, fluid-filled chambers
    in a dynamic state, etc. How is it that plus lenses interact with these
    structures to reduce myopia? What is it about the age of the eye that makes
    it work better in younger people? I have a theory-- plus lenses allow
    relaxation of the ciliary muscle in those individual who have accommodative
    myopia and in no others.

    THE EYE IS MUCH MORE THAN AN EQUATION OTIS. Structure reflects function
    Otis. If the functioning of the eye changes after plus lens treatment then
    you need to tell us how and where the change(s) occurs. Again I state--
    OTIS DOESN'T ANSWER THIS BECAUSE HE CAN'T. HE DOESN'T UNDERSTAND THE
    FUNCTIONING OF THE EYE. The eye is not an equation Otis.

    I'm glad you read Donders and Helmholtz. And forget the box camera analogy.
    You seem to perceive the eye as either an equation or some kind of simple
    mechanical device that you can easily comprehend.

    Wrong Otis. Axial length of the eye is measured objectively by ultrasound
    in an A-scan. I can tell you for certain that you can repeatedly measure
    the axial length of the adult eye over a time span of years and it does not
    change. Length is not an extrapolation of refractive measurements Otis.

    Your theories, however, are an extrapolation of the few cases of
    accommodative myopia where you can demonstrate ciliary muscle relaxation
    using plus lenses.
    Exactly Otis. This will work for young people whose myopia is due to
    increased ciliary muscle tone. These individuals are called accommodative
    myopes and constitute the minority of the myopic patients. Your theory
    applies only to younger individuals with over-functioning ciliary muscles.

    I see many many children and adolescents who have been myopic for a long
    period of time and have never received a minus lens. Why do they some
    continue to progress toward myopia Otis? As pointed out by MT, they have a
    net plus power to the optics of their eye as if they are wearing full time
    plus lenses yet their refractive status does not improve and oftentimes
    worsens. Why is that Otis?
    Again, you have an equation-based understanding of the eye. It is like a
    black box to you and you don't understand what's inside it and how it works.
    Structure reflects function. Any changes within the eye caused by your plus
    lenses MUST be reflected in a change in the anatomy/physiology of the eye.
    Don't you wish you knew it? You will never gain credibility in the medical
    community until you demonstrate it.
    You don't understand how the eye works. You can't explain it.
    I think I know what explains your observations-- your plus lens treatment
    works for accommodative myopes only.
    I will have to ask you to explain what you are saying in another way. Are
    you saying that if you give the eye minus lens power that its refractive
    state will change to become more myopic? If so, that CAN happen but only in
    some younger patients (with functioning ciliary muscles) if you give them
    more minus power than is needed to focus the image on the retina. These
    patient may develop an accommodative myopia as we have discussed at great
    length already (Geez!!). But this does not apply to all young people and
    certainly does not apply to post-presbyopic patients. These patients will
    reject the excessive minus power and will see more clearly when their
    anatomical myopia is corrected precisely. Your equation is an
    oversimplification and does not apply to most patients. They eye is not an
    equation Otis. All myopes are not accommodative myopes Otis.
    OK, let's assume some other kind of picture of the eye. How then according
    to your equation theory of the eye, or your black-box theory of the eye,
    does LASIK work. The fact is that refractive techniques all are based upon
    an understanding of the components of the eye and how they function
    together. Structure reflects function. LASIK, cataract surgery, etc. would
    never have been developed if we all had a black-box or equation based theory
    of the eye.
    When I ask about age it has nothing to do with the persons ability to
    understand or follow directions. It has to do with how the eye functions
    and the fact that it's ability to change refractive state is quite high in
    younger individuals because of the functioning (and OVERfunctioning) of the
    ciliary muscle. Your plus lens technique can only work on myopes with
    overfunctioning ciliary muscles (i.e. accommodative myopes).
    So if you are 65 you don't care about your refractive status? Anyway, are
    you ready to admit that your plus lens theory is ineffective in presbyopic
    patients? If so, can we break out the dreaded minus lenses for those people
    (who apparently don't care about their refractive status anyway)?

    I could tell you precisely if you paralyze the ciliary muscle with a
    cycloplegic agent and then do a refraction on them. An important point is
    that not all of them will "go down". As stated above, some will adapt to
    the minus lens and will develop a counterbalancing increased ciliary muscle
    tone. These are called accommodative myopes. Some will reject the minus
    lens and will see blur at distance. Some will show no lasting effect of the
    minus lens treatment at all and will be neutral just as before. And
    besides-- who is putting such an excessive minus lens on anyone anyway? Why
    do you think this kind experiment relates to the way humans are treated by
    eye doctors? If eating too much causes obesity do you propose that we ban
    food altogether?
    OK, now we are getting somewhere. Your plus lens treatment is best suited
    for young engineer-pilots.
    Retinal detachment is a concern for high axial-length myopes. It has
    nothing to do with myopia induced by increased ciliary muscle tone.

    You know what I mean. Explain how it works. Explain what part of the eye is
    changed. Show the studies that demonstrate it.
    Sometimes primate studies are quite useful. But sometimes they are not. I
    will listen to animal studies unless they are proven not to apply to humans
    in a subsequent study.

    No, I just haven't seen any data from you yet. Only declarations and
    second-hand case reports. You just keep repeating that your approach DOES
    work and that we are fools and conspirators for not seeing it your way.
    Your method likely works for the subpopulation of young accommodative myopes
    but not for other myopes.

    What really irks me Otis is that people like you, who propose this kind of
    snake-oil fix for vision problems, can mislead people. I have had patients
    who told me that they heard this kind of voodoo crap on the radio from Paul
    Harvey or bought some training materials after seeing television
    advertisements starring Marriet Hartley. I respect your right to think
    whatever you want to think. I hope you go off and do some studies to prove
    yourself right and the rest of us wrong. But until then, I'm placing my
    bets on the understanding of the visual system that the majority of us have.
    It works, it's effective, and it helps people. You are misleading people
    and in my opinion have an imperfect understanding of what you are talking
    about.
     
    RM, Nov 16, 2004
    #2
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  3. Otis Brown

    Dr. Leukoma Guest

    I think that the point is that Otis and his ilk need to be able to show
    that their proposed treatment works. This has not been done. Then they
    can worry about the mechanism. They cannot prove that it works, and so
    they hide behind this wall of obfuscation. All they need to do is a
    controlled study. Of course, this will never happen, because it needs to
    be done by engineers, according to Otis.

    DrG
     
    Dr. Leukoma, Nov 16, 2004
    #3
  4. WOW-- I was told about this newsgroup by a faculty member from an opto
    school. Very interesting! To cut through the BS I will simply snip
    out some comments from the last long-winded reply with which I agree.

    The issue of myopia prevention has a life of its own. It has gone on
    for generations. It seems to be a complicated topic and there are
    probably genetic and racial differences that we yet do not understand.
     
    Louis Pasteur, Nov 16, 2004
    #4
  5. Otis Brown

    Otis Brown Guest

    Dear RM,

    Again, thanks for your commentary -- I always
    appreciate the thought.

    I consider the minus lens to be "obvious", and
    the very few people have any interest in
    "prevention" when it must be accomplished.

    My interest was is "understanding" the difficulties
    of prevention -- when seen from the perspective
    of optometry. And is was Jacob Raphaelson who
    supplied that persepctive -- in his story
    of "The Printer's Son". That convinced me
    that true prevention could never be "worked"
    by an optometrist -- and the the person
    concerned with it would have to make
    that kind of decision himself -- however
    hard that might be for him.

    As far as representing the behavior of the
    natural eye -- as dynamic -- then I judge
    that has been accomplished on and "engineering-scientific"
    level, were resolution is in the facts themselves --
    and not in your opinion.

    I do think you for absolutly rejecting ALL primate
    studies, and ALL animal studies as being to
    "disturbing" to evalulate. But no one is
    forcing you to "think straight", and
    certainly I am not going to do it.

    But I will again save this and forward it
    to the interested parties.

    I do agree that the "high-level" appreciation of
    testing the nautral eye as an "input" versus "output"
    has never occurred to you -- and this type of
    analytic thinking can NEVER be reduced to a "quick-fix"
    supplied to the public that walks in off the street.

    I could not do it. And I would never "pressure" you
    to do it. But for those who can "push-back", and
    for a different perspective "paradigm", then I believe
    that a preventive alternative is possible -- even
    if you can not be part of it.

    Thanks,

    Otis

    _______
     
    Otis Brown, Nov 16, 2004
    #5
  6. Otis Brown

    RM Guest

    Oh, so I'm long-winded huh? Well I guess you are right. Sorry ;)

    I've got to apologize to everyone. I normally just lurk around this NG and
    occasionally throw in my 2 cents. But about a week ago Otis the engineer
    went off on his rant and it just pissed me off. I've tried to explain as
    much as I can to him over and over again but it's to no avail. Last night I
    even looked over some old posts by Otis from about a year ago and all the
    same points and issues that I've made have been discussed with him by others
    previously. I realize that there is no way to get the guy to ease up. The
    problem is that he acts like he is some kind of intellectual expert on
    vision and he could easily mislead people who use this newsgroup. His
    prevention techniques have no chance of helping 95% of all myopes.

    I think I will just put together a "disclaimer" about Otis and post it in
    reply to any "help" he tries to tell someone when they innocently ask a
    question in this newsgroup. I will try to make it fair and informative. I
    could do it for Rishi and Evaristo also but they do a pretty good job of
    discrediting themselves. Otis the engineer however uses mathematical
    equations and drops the names of real doctors which creates a false aura of
    credibility around the BS he spouts.
     
    RM, Nov 16, 2004
    #6
  7. Otis Brown

    Otis Brown Guest

    Dear RM,

    Since you seem to have a scientific "bent", here
    are the result of ADOLECENT-PRIMATE studies to
    determine the amount by which the primate eye
    changes its refractive status -- as the average
    visual environment is changed.

    Briefly -- a population of natural primates were
    placed in a situation where an accommodation delta
    (long-term) of -0.8 diopters whas iduced in the
    test group. The control group had no delta.

    The refractive status of the test group changed
    according to the function e ^ (-t/TAU), while
    the refractive status of the control group
    remained the same.

    Below is the calculation for the correlation coefficient
    for the accommodation system -- relative to the
    refractive state of these natural eyes.

    __________________



    FOCAL STATE CORRELATION TO THE SNELLEN EYE CHART

    Initially, the monkeys in this experiment were, on the average,
    slightly nearsighted. Their eyes were 20/25 at the start of the test and
    became more myopic (20/80) at the end of the test. Wild monkeys have 20/20
    vision with an average focal state of +0.7 diopters.


    THE CORRELATION COEFFICIENT DATA AND CALCULATION

    (See Fortran graph for data.)

    Unexplained Variation = 0.07227
    Explained Variation = 1.23809
    Total Variation = 1.31037

    Correlation Coefficient = 0.97203



    This data, which represents the fundamental behavior characteristic of
    the normal eye, correlates with the equation:

    Focus = Offset + Accommodation + Delta * [1 - EXP(-t/TAU ) ]


    STUDENTS "T" CALCULATION FOR THE CORRELATION COEFFICIENT

    Was the correlation coefficient from this experiment accidental? Did
    Dr. Young randomly obtain 0.972 for the monkeys in the test when the actual
    population correlation coefficient was zero? This assertion can be checked
    by use of the students "t" distribution:

    r
    t = ------------------------
    ___________________
    / 2
    / 1 - r
    \ / ---------
    \/ n - 2

    Where:

    n = 23 (Number of measurements made)

    r = 0.97 (Correlation coefficient from the experiment)

    for v = 21 (Degrees of freedom = 23 - 2)

    t = 3.819 (Value for 99.9 percent confidence limit)
    ..001

    2
    t = 0.97 / SQRT [ ( 1 - 0.97 ) / ( 23 - 2 ) ]

    t = 18.28


    Since 18.28 exceeds 3.819 (the 99.9 percent confidence limit) we can
    reject the idea that the Helmholtz-passive concept is correct. There is a
    very high correlation between the average value of accommodation and the
    focal state of the normal eye.


    THE REPEATABILITY OF THIS EXPERIMENT TO OBTAIN
    THE SAME CORRELATION COEFFICIENT

    The Range of Possible Values for the Correlation Coefficient

    If the experiment is repeated 100 times, will we get the same
    correlation coefficient? What is the range of correlation coefficients that
    we can expect from the large population of normal eyed individuals?

    If from a bivariate population with a correlation coefficient, RHO, all
    samples of size n are taken, then:

    Z - m
    (r) (RHO)
    z = -----------------
    Sigma

    Where:

    Z(r) = 0.5 * ln ( (1 + r) / (1 - r) )

    m(RHO) = 0.5 * ln ( (1 + RHO) / (1 - RHO) )

    Sigma = 1 / Square Root (n - 3)

    z = Abscissa for area under probability curve

    Values:

    r = 0.97

    Z(r) = 2.092

    n = 23

    Sigma = 0.2236

    Z = +/- 2.58 for 99 percent confidence

    Area = 1.0 - 2 * ( 0.495 ) = .01

    By rearranging the equation:

    m(RHO) = Z(r) +/- (Sigma * z)


    using values: r = 0.97, n = 23, z = +/- 2.58

    m(RHO) = 2.092 +/- 0.57688


    Using look-up tables:

    m(RHO) = 2.6688 and therefore the upper limit for RHO is 0.99

    m(RHO) = 1.5151 and therefore the lower limit for RHO is 0.90

    In other words, given the results of this experiment, we can conclude
    that it is virtually certain that the large-scale population coefficient
    will lie between 0.90 and 0.99 for all primate eyes.

    There is a very high correlation between the normal eye's accommodation
    system and the focal state of the normal eye. The concept that the normal
    eye behaves as a (dynamic) neurological control system is strongly supported
    by direct factual data. The concept that the normal eye is passive in its
    behavioral characteristic is rejected by direct factual data.

    These statistical tests are standard and conclusively demonstrate the
    truth that the normal eye DOES NOT obey the Helmholtz-passive model for the
    normal eye's behavior. It is very unlikely that future experiments will
    support the Helmholtz-passive model of the normal eye's behavior.

    ___________________________

    The conclusion does not analyize the "box camera" picture
    of the eye you love to analize -- because:

    1. It is not reasonble.
    2. It is not accurate in predicting the
    behavior of the natural eye.

    Please remember these are analytical arguments -- not
    to be part of "optometry" at all.

    RM -- Please tell me again that there is NO CORRELATION
    between the refractive status of THE NATURAL EYE and
    it average-visual environment.

    Best,

    Otis



    __________________________


    CONCLUSIONS

    There are two powerful conceptual tools available for dealing with
    difficult servo problems -- analysis and synthesis. Since it is almost
    impossible to gain access to the accommodation system (that controls the
    eye's long-term focus), an indirect approach is required to establish the
    fundamental behavior characteristic of the normal human eye.

    An indirect approach results in the development of mathematical models.
    By constructing two reasonable physiological models for the normal eye's
    behavior, we can develop two sets of theoretical predictions. We can then
    decide, on the basis of direct experimentation, which model is more fully
    confirmed by the available experimental evidence.

    An analysis of the focal design requirements of the normal eye
    demonstrates that each eye must maintain a dynamic accuracy of better than
    1.5 percent while growing to maintain normal vision. (5)

    In synthesis, we develop a dynamic design which will account for the
    maximum number of facts known about the normal eye's focal setting action.
    Since the human body relies on feedback control principles in its design --
    accommodation, temperature, and pH levels -- we find it appropriate to apply
    this concept to the eye's focal behavior. The opposite suggestion, that the
    normal eye ignores the accommodation signal while growing, leads to a theory
    that is incapable of accurate quantitative predictions.

    This analysis/synthesis approach points to an equation that accurately
    predicts the dynamic behavior of the human and primate eye. The equation
    can support a procedure that will be effective in preventing
    nearsightedness, if the eye's dynamic behavior is understood, and the
    preventative procedure is assiduously carried out.

    Accuracy and stability of the normal eye's behavior can be understood
    by modeling the eye as a servomechanism. An eye with this type of control
    system will exhibit a time-constant effect if subjected to a step-change in
    the eye's visual environment. In this experiment a "brute force" change was
    induced in the average visual environment. A time-constant response was
    measured in the eye's focal status. The theory which is compared to this
    concept is a Helmholtz-passive theory of the eye's focal behavior.

    The dynamic analysis leads to a general equation for the long-term
    behavior of the normal eye. On the basis of this experiment we suggest that
    the dynamic (cybernetic) model is strengthened.

    As with most mathematical models, certain effects (e.g., noise and
    perturbations in the system) have not been included. These effects will be
    assessed and represented in later chapters. Our experience, however,
    indicates that this model is very accurate with respect to other dynamic
    tests that have established the normal eye's behavioral characteristic.

    In the absence of any other experimentally confirmed equation we can
    tentatively conclude that this test confirms the accuracy of this equation
    -- within the limits imposed by the expeerimental data that is available to
    us.


    REFERENCES

    1. Young, F., Leary, G. VISUAL CHARACTERISTICS OF APES AND PERSONS,
    (207-225) Progress in Ape Research (1977)

    2. Brown, O., Berger, R. A NEARSIGHTEDNESS COMPUTER, (343-346), The 7th
    Annual New England Bioengineering Conference (1979)

    3. Brown, O., Young, F. PHYSIOLOGICAL MODELING: THE LONG-TERM GROWTH OF
    THE EYE, (133-136) The 8th Annual New England Bioengineering Conference
    (1980)

    4. Young, F. THE EFFECT OF RESTRICTED VISUAL SPACE ON THE PRIMATE EYE,
    American Journal of Ophthalmology, Vol. 52, No. 5, Part II, November
    1961

    5. Brown, O., Young, F. THE RESPONSE OF A SERVO CONTROLLED EYE TO FOCAL
    PERTURBATIONS, The 2nd Annual conference of the IEEE Engineering in
    Medicine and Biology Society (1980)

    6. Hayden, R. DEVELOPMENT AND PREVENTION OF MYOPIA AT THE UNITED STATES
    NAVAL ACADEMY, Archives of Ophthalmology Volume 25, #4 (April 1941)



    ________________
     
    Otis Brown, Nov 16, 2004
    #7
  8. Otis Brown

    Dan Abel Guest

    occasionally throw in my 2 cents. But about a week ago Otis the engineer
    went off on his rant and it just pissed me off. I've tried to explain as
    much as I can to him over and over again but it's to no avail. Last night I[/QUOTE]


    I was wondering what you were doing. Otis has the One True Faith, which
    he calls true-prevention, I guess to differentiate it from
    false-prevention? It's no good to argue with him, he's already decided
    what he believes.


    I think that Bev has already done something like this. She hasn't named
    Otis or described his belief, but simply said that if it sounds too good
    to be true, it probably isn't. I think that it would be useful for you to
    put together a quick "disclaimer". Otis always posts the same beliefs, so
    you wouldn't need to edit it each time.
     
    Dan Abel, Nov 16, 2004
    #8
  9. Otis Brown

    Dr. Leukoma Guest

    There is a distinct possibility that Otis is two bricks shy of a full load.

    DrG
     
    Dr. Leukoma, Nov 17, 2004
    #9
  10. Otis Brown

    RM Guest

    What an elegant and romantic story about what spawned your interest in
    myopia prevention Otis.

    But I have come to accept DrG's suggestion that you have some real
    psychological issues. Perhap you picture yourself as some kind of martyr in
    a "war" against the convention wisdom of modern-day eye doctors.

    You will never address my questions directly. You reply obliquely to
    difficult questions by just reverting to your mathematical equations and
    black-box input/output analysis of the human eye. How does the old saying
    go-- "if you can't dazzle them with brilliance then baffle them with
    bullshit".

    I was a fool to think that a logical discussion with you could change or
    dampen your profuse opinionated postings in this newsgroup.

    ------------
     
    RM, Nov 17, 2004
    #10
  11. Otis Brown

    RM Guest

    Otis, I never said the anything in my posts about the correlations between
    the natural eye and it's visual environment.

    By the way Otis, I and everyone else who reads this newsgroup is undoubtedly
    impressed by your mathematical skills. But the eye is composed of
    biological materials and you never seem to be able to discuss or explain
    anything in any other way than equations and black-box circuit diagrams.

    How does the old saying go-- "if you can't dazzle them with brilliance then
    baffle them with bullshit".


    Nope Otis, you can gain access to the accommodation system (which controls
    primarily the eyes short-term focus). You can observe how it functions in
    real-time. You can paralyze it via the use of cycloplegic drugs. You can
    observe the changes it makes on the crystalline lens.
    Otis seems to favor only indirect approaches.

    Yours directly
    RM
     
    RM, Nov 17, 2004
    #11
  12. Otis Brown

    Dr. Leukoma Guest

    That is incorrect. I am not impressed by sophistry.

    DrG
     
    Dr. Leukoma, Nov 17, 2004
    #12
  13. Careful, there. Every process in our bodies is, to some extent,
    describable by differential equations, chemical reactions, biomechanical
    descriptions, etc. Good models (with the stress on good) take these
    factors into account at an appropriate level, and can teach us alot about
    physiology.

    Of course, the model we're talking about now has been invalidated at every
    corner, yet we continue to discuss it for some reason.

    Scott
     
    Scott Seidman, Nov 17, 2004
    #13
  14. Otis Brown

    RM Guest

    Scott,
    You are certainly correct. I harken back to the days when I was in graduate
    school taking electron microscopic pictures of the eye while some of my
    fellow grad students were deriving differential equations to describe the
    psychophysics of color vision. I personally have a biological bent on
    things. I want to see it, know what makes it up, and know how it operates.
    Many of my graduate student friends, as well as Otis the engineer, have a
    different approach. Both approaches have value.

    Nevertheless, the functions that psychophysicists describe mathematically
    must definitely have anatomical, physiological, and biochemical correlates.
    We can describe anything as if it were a black box or a circuit diagram, but
    that doesn't help us understand how it works unless we can open the box and
    see what's inside. What good does it do to describe mathematically how
    visual acuity is diminished when a cataract develops unless you know what
    the cause is, which therefore leads you to understand what the problem is
    and how to correct it.

    Not to be long-winded again, but I acknowledge your point.

    Perhaps more important is that Otis' equation which describes (I think) that
    increasing the minus lens power in front of the eye leads to an increased
    refractive error in the eye-- i.e. his "stair-step" equation-- does not
    apply in most cases. It might be true in a subpopulation of young people
    who develop accommodative myopia, but not in most others. Some young people
    report blur when you overminus them and reject the lens outright. Some
    people can clear their vision with the excessive minus lens but, after
    wearing it for awhile, when you retest them you find they have the same
    original refractive error. Otis' lack of understanding about what is
    actually inside the black box causes him to overlook that the action of the
    ciliary muscle is responsible for why some people seem to respond to plus
    lens treatment.
     
    RM, Nov 17, 2004
    #14
  15. Otis Brown

    Dr. Leukoma Guest


    But alas, there is no proof whatsoever of its validity in any subset of
    myopes.

    DrG
     
    Dr. Leukoma, Nov 17, 2004
    #15
  16. Otis Brown

    RM Guest

    Yes, perhaps there is no scientific proof. It is just another "case report"
    or a clinical observation that I have made that causes me to actually agree
    with Otis (ugh!) that some accommodative myopes can perhaps benefit from 1)
    not wearing their minus correction unless they absolutely need it, and 2)
    considering using weak readers when doing prolonged near work.

    Of course most of them won't wear the plus lenses at near because it's
    impractical. Nor would I. And regardless, I still have never seen any
    "devastating effects" from a minus lens. Certainly not retinal detachment
    as Otis tried to imply in one of his recent posts.
     
    RM, Nov 18, 2004
    #16
  17. Otis Brown

    Dr. Leukoma Guest

    Actually, I meant that there is no independent proof of the predictability
    of his mathematical equation.

    Lecturing optometrists on accommodative myopia is like preaching to the
    choir.

    DrG
     
    Dr. Leukoma, Nov 18, 2004
    #17
  18. Otis Brown

    Otis Brown Guest

    RM > But the eye is composed of
    ______________

    Dear Scott,

    Thank you for that observation. To a certain extent,
    learning to ask the "right" questions -- leads to
    better answers.

    The type of questions these ODs ask remined me of
    a beginning-tech who does not understand
    the design of a rocket control sytem.
    He will ask detailed questions about individual
    resistors, hydrolic pumps, in great detail -- but
    will not understand the over-all concept of
    stability and control. You can not dissect a
    "dead eye", taking all the parts, lens, cornea,
    retina, and examining them under a microscope -- and
    then have any concept of how these separate parts
    work as a "system". They insist that "I" do it,
    and I insist they don't know how to establish the
    behavior of a natural physiological control system.
    Specifically:

    ________________


    Measurements on individual optical components of the eye are exacting,
    and it is difficult to say which optical component causes a specific problem.
    The researcher can be aided by an engineering approach to this complex system,
    since the eye is an intricate data-processing system. The primary
    neurological process is controlling a dynamic (100 day time-constant) focal
    system on a microscopic level.

    _________________

    I do appreciate that they are working very hard to find
    a simple solution that will satisfy the general
    public that walks into and office. The public will
    in fact be very angry with any attempted discussion
    of the preventive alternative -- a fact that I acknowlege.

    My primary interest is to face this difficult truth,
    and follow the suggestions of Dr. Colgate on this
    issue. I am more interested in accounting
    for the eye's high-level of technical accuracy,
    rather tha being particularly concerned with
    the limited goal of an OD.

    You find out how a system behaves, and then inducing
    "perturbations", and seeing how the system
    responds to these transient disturbances.
    That is what a "systems" approach is all about.
    Here is a review of that analysis.

    Enjoy my friend. New ideas and discussions of
    these concepts make for great analysis
    over wine and cheese receptions.

    Otis
    Engineer


    ____________________


    CONCLUSIONS

    If the normal primate eye is to achieve a high level of focal accuracy in
    the presence of continuous perturbations, the author has concluded that the
    eye must employ dynamic control to set its focus. This chapter presents a
    high performance model that provides a focal control mechanism that is, as far
    as we can determine, consistent with all the physical evidence pertaining to
    the normal eye's behavior.

    The model evolved as a result of a long investigation in which many
    preliminary approaches were discarded because they led to inconsistencies. It
    is clear that the number of approaches that can satisfy the evidence is
    limited. An electrical engineer, when faced with similar engineering
    requirements for focal precision, will develop this type of design to meet the
    accuracy requirements of the eye.

    The philosophy of this chapter has been to study the focal control
    process of the normal eye by treating it as a design problem. The procedure
    followed is to develop a system model with the focal performance capability
    comparable to the normal primate eye.

    Measurements on individual optical components of the eye are exacting,
    and it is difficult to say which optical component causes a specific problem.
    The researcher can be aided by an engineering approach to this complex system,
    since the eye is an intricate data-processing system. The primary
    neurological process is controlling a dynamic (100 day time-constant) focal
    system on a microscopic level.

    It should be remembered that there are several major optical components
    of focus, any of which can dramatically affect the focal state of the normal
    human eye. While the eye is growing, these components are continually
    changing in value.

    When a physiologist experiments on this complicated data processing
    operation, he is in the same position as a technician who is presented with a
    computer system that determines rocket guidance. He is then told to make
    measurements on the individual components of the device until he determines
    which component establishes the tracking accuracy of the system. Actually,
    the physiologist is in a more difficult position because so much of the data
    processing of the eye is at the molecular level, almost beyond the reach of
    his instruments.

    The mathematical systems concepts used in automatic control evolved out
    of necessity, as it became apparent that modern servo systems could not be
    understood by studying the characteristics of their individual components.
    This truth applies just as strongly to complex processes encountered in
    biological-optical systems. The electronics engineer can establish a solid
    mathematical foundation for an analysis that will accurately predict the
    normal eye's focal control response.

    The same equation that precisely anticipates the normal eye's
    perturbation control also predicts that nearsightedness can be avoided. In
    addition, the equation can give conceptual and practical guidance to a
    successful nearsightedness avoidance effort.

    There are other more sophisticated means of determining the eye's
    tracking accuracy, and these techniques will be developed in the next chapter.


    APPENDIX

    Focal Accuracy: The eye is about 2.4 cm in length. The eye must have a
    focal power of 57 diopters to focus light on the retina. The focal status
    histogram for normal eyes has a standard deviation of .843 diopters, and a
    probable error of .843 X .674 = .568 diopters. We may, therefore, specify
    that the eye has a tracking probable error of .568/57 or approximately one
    percent of its total focal power. This is the worst-case value. For a number
    of reasons, we should expect that the tracking accuracy of the normal eye will
    be considerably better than one percent. In the next chapter we will provide
    an analysis that demonstrates that the actual tracking probable-error is on
    the order of 1/10 diopters.


    REFERENCES

    1. Young, F., Leary, G. VISUAL CHARACTERISTICS OF APES AND PERSONS
    (207-225) Progress in Ape Research (1977)

    2. Brown, O., Berger, R. A NEARSIGHTEDNESS COMPUTER (343-346) Proceedings
    of the 7th New England Bioengineering Conference (1979)

    3. Brown, O., Young, F. PHYSIOLOGICAL MODELING: THE LONG-TERM GROWTH OF
    THE EYE Proceedings of the 8th New England Bioengineering Conference
    (1980)
     
    Otis Brown, Nov 18, 2004
    #18
  19. Otis Brown

    Dr. Leukoma Guest

    (Otis Brown) wrote in

    Please state the name of the author of this article as well as the journal
    and year in which it was published. I see that the bibliography references
    only three articles, all published more than two decades ago. That is
    ancient history.

    DrG
     
    Dr. Leukoma, Nov 18, 2004
    #19
  20. Otis Brown

    Otis Brown Guest

    Dear DrG,

    Subject: Sub-set of eyes with refractive status of
    -1/2 to -3/4 diopters (20/50 to 20/70)

    This subject would depend on what is considered
    "proof" by the engineer-pilot concerned with the
    issue.

    Provided the effort is run under "scientific" (not
    medical) protocols -- then I believe that
    major successful (i.e., pass the Snellen-MDV,
    pass the 20/20 line) could be achieved
    but the pilot himself -- who had the
    same motivation that Shawn did.

    Under proper circumstances I would gladly
    give of my time to organize this effort
    at a four year aeronautical collage
    among the (new) scientists that are
    concerned with it.

    Please remember -- even completely successful
    results (70 percent clear to 20/20) these
    results could not be reduced to dealing
    with the general public -- in 15 minutes.

    Further, the goal is true-prevention, which
    would be the real goal of this effort.

    I am ready to do it -- are you?

    Best,

    Otis
    Engineer
     
    Otis Brown, Nov 18, 2004
    #20
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