How do you use an autorefractor to test sight?

Discussion in 'Optometry Archives' started by andrew Judd, Aug 19, 2003.

  1. andrew Judd

    andrew Judd Guest

    Hi

    Can anybody help me out?

    If I had an autorefractor could i confidently measure somebodies
    eyesight to within -.5D or better?

    Would i get direct readings of +/- and direct readings of astigmatism
    =/- and angles of astigmatism?

    How does the device know the eye is fully focused for the distance?
    Do you look at a target?

    Can you get single eye readings?

    Why are autorefractors not used to measure sight in opticians offices?

    Please note i am going to post a related question on instrument
    myopia.

    thanks

    Andrew
     
    andrew Judd, Aug 19, 2003
    #1
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  2. andrew Judd

    Dr. Leukoma Guest

    Yes, I can relate. My 2.5 diopter myopic patient was prescribed -7.50
    diopter spectacles from an autorefractor at another clinic. The net result
    is that I am still performing refractions.

    DrG
     
    Dr. Leukoma, Aug 21, 2003
    #2
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  3. andrew Judd

    andrew Judd Guest

    Many thanks to all those who replied to my two questions on

    1. Autorefractors

    2. Instrument myopia

    I am intending to construct a study to see what kind of influences are
    at work to explain the variability shown by Autorefractors.

    This study will be influenced by the knowledge of the mind that has
    become available since the split brain patient studies. Studies which
    are still continuing.

    Effectively every human being has two different minds. We can say
    we can live in our 'heads' or we can be 'poetic' or we can be
    'balanced'.

    Studies have shown myopes tend to live in their heads. Effectively
    this represents a denial of right brain functioning.

    We dont see with our eyes but with our minds. Our sense of sight
    only guides are imagination to what is outside of our heads. If we
    think we know what is outside of our heads we cannot truelly imagine
    what it is we do see. Seeing is believing - we find it hard to
    believe what we cannot see. A mind that cannot imagine outside a
    narrow set of parameters is myopic and restricted.

    It can be reasonably considered that myopes, living in their heads,
    are unable to effectively and accurately imagine what it is they do
    see. Instead their imagination is dominated by what they think they
    see, and their more creative imagination is denied to them.

    The seeing process therefore is distorted or short circuited. They
    *think* they *know* what they see *before* they have allowed their
    imaginations to see what actually *might* be there.

    The work of Dr Roberto Kaplan OD has shown very effectively that each
    specific angle of astigmatism is related to a specific mental
    conflict. He collected this data by just noting prescriptions and
    personality profiles. He is still fine tuning these observations
    and I found him to be of further help to me when I spoke to him
    recently.

    I have so far found 100% correlation between the work of Dr Kaplan and
    the people I have so far interviewed. These patterns are remarkably
    strong. Each person interviewed has been surprised that their mental
    behaviour should be so strongly present in their glasses.

    Briefly, I think it is ok to say what Dr Kaplan found, which is
    published in his book 'Conscious Seeing'

    Here are the two none oblique angles

    180 left or right eye
    -----------------------

    Stubbornness inflexibility inpatience

    90 left or right eye
    ------------------------

    lack of committment, lack of voicing truth, lack of love.


    The oblique angles depend on which angle and for which eye.


    So how do we account for the difficulty some people have in using an
    autorefractor?

    Astimatism is a conflict, and it is a conflict that is more or less
    continually present in the mind.

    Myopia can be considered to be a perceptual distortion. We already
    know that when the mind thinks that what is observed is closer to it,
    than in reality it is, the eye will accommodate. We know this
    because we know about instrument myopia.

    Clearly it is quite possible that Myopes, who are excessively left
    brained and who have an 'I' or egocentric view of the world do in fact
    imagine the World is closer to them than in reality it is.
    Egocentricity is, after all, imagining we are more important that in
    reality we are.

    Perhaps people who have strongly different reactions to autorefractors
    are less sure about their self oriented manner than those who show no
    reaction?

    The variability of autorefractors is intriguing and deserves further
    study.

    Thanks for your help so far. If anybody has any suggestions advice
    and so on as to go about such a study so that it can be properly
    published supervised and so please feel free to let me know.

    Andrew
     
    andrew Judd, Aug 21, 2003
    #3
  4. andrew Judd

    Otis Brown Guest

    Dear Mike,

    What is it cost of a standard "auto-refractor"?

    $10,000? $5,000?

    Best,

    Otis
     
    Otis Brown, Aug 21, 2003
    #4
  5. andrew Judd

    andrew Judd Guest

    (drfrank21) wrote in message >
    What you say is fair comment. But at the heart of the matter you
    cannot believe that I have found any meaningful results - I believe I
    have been able to back up Dr Kaplans empirical data with my own
    observations.

    If you ask somebody if they are stubborn impatient and inflexible and
    they agree, or they say 'absolutely not' this is a different response
    to 'well no not really....er well what do you think?...i would not say
    i am really...my wife might be a better person to ask though'

    These patterns are remarkably strong.

    You cannot see what you cannot believe.
    I am sorry Frank but this is an unscientific response based on your
    opinion that it cannot be anything other than what fits your current
    perceptions.

    Before we can say what *might* be happening we need to find out what
    *is* happening and the attempt to explain what we find.

    Andrew
     
    andrew Judd, Aug 21, 2003
    #5
  6. andrew Judd

    andrew Judd Guest


    What about second hand or not working/repairable? Is there a
    reliable second hand market for these devices?

    For my study absolute values are not necessarily that important.
    Part of the study will be to look at what causes measurable variation
    in autorefraction measurements.

    Thanks

    Andrew
     
    andrew Judd, Aug 21, 2003
    #6
  7. andrew Judd

    Dr Judy Guest

    snip
    Has he published this in any peer reviewed Psychology/Mental Health
    journals? Sounds far fetched to me.
    How big was your sample size? Did you use standardized, personality testing
    administered by a trained psychometrist? Was the personality testing done
    before the refraction measure?

    Dr Judy
     
    Dr Judy, Aug 21, 2003
    #7
  8. andrew Judd

    drfrank21 Guest

    Andrew, I am sorry about the apparent dysfunctionality in your family
    but I'm pretty certain that your refractive error (astigmatism in this
    case)
    had no role in this. I'm confused about your cause/effect here.
    I'm not really sure if you think that the parent/child
    relationship you described caused the astigmatism or that the
    astigmatism caused the "clash".

    It's not- it's more along the lines of palm reading.


    Andrew, hate to bring it up, but that (ie 110 axis cylinder) is not
    that
    uncommon. So is 70 degs, 115 and so on.



    Somebody with that kind of
    And are you assuming all this in minus or plus cylinder form?
    I realize that you are entirely sincere in this and I truly wish you
    the best of luck in your quest. But has it crossed your mind, just a
    bit, that maybe astigmatism should be taken at just face value for
    what it is- namely just astigmatism. I truly think that you can
    fulfill
    a self-realizing prophesy with such a strong bias. You mentioned
    science- a "valid" study would have to be blinded (ie asking a
    valid standard psychological personality profile) to a valid sample
    size with the tester not aware of the subjects refractive error. Has
    Kaplan done this? Doesn't sound like you have been objective
    in your own "little" study.

    frank
     
    drfrank21, Aug 22, 2003
    #8
  9. andrew Judd

    andrew Judd Guest

    Dr Judy

    Your questions are very hostile. I dont have a problem with
    hostility providing that behind the hostility there is a genuine
    desire to learn something or a genuine desire to help me learn
    something.

    I get the impression that you have a fixed point of view. A rigid
    inflexible view.

    Often hostility towards others demonstrates a hostility towards
    yourself.

    If you are genuinely interested in finding out more about Dr Kaplan it
    would be easier to do this from a position of respect rather than
    disrespect.

    to be honest when i have previously be involved with your questions
    and opinions I have not felt so good afterwards.

    I just dont need your hostility.

    Thank you

    Andrew
     
    andrew Judd, Aug 22, 2003
    #9
  10. andrew Judd

    andrew Judd Guest

    Jan

    Absolute means that they are measured relative to some known definate
    reference point. So 1D is the focal power required to produce a
    focus at one metre using parallel light. A -1D myope measured
    using a retinoscope and trial lenses could be said to have an absolute
    refraction of -1D

    I dont need a autorefractor that measures absolute values. If my
    autorefractor measured -2 but was consistant in measuring variations
    around this -2 then this would be sufficient.

    All i need is an autorefractor that will measure the approximate
    variation in diopters that the subject displays as they answer a
    series of questions.

    If their is no variation it does not matter what the readings show.
     
    andrew Judd, Aug 22, 2003
    #10
  11. andrew Judd

    Otis Brown Guest

    Question:

    How is Andrew going to determine how much variation
    is due to the Auto-refractor, and how much
    variation is due to normal changes of (noise) in
    the eye.

    i.e., If you took a person and measured his eyes,
    consistently on a daily basis, I bet you would
    get variations of +/- 1/4 diopter, and probably
    as high as +/- 1/2 diopter.

    Just a consideration of the conceptual methods.
    This should be checked before the study is started.

    Best,

    Otis
    Engineer
     
    Otis Brown, Aug 22, 2003
    #11
  12. andrew Judd

    Dan Abel Guest


    Seems like it to me, or like astrology. In both cases you are using
    something to predict personality by using something that is measurable but
    logically shouldn't affect personality.


    It seems reasonable to me that uncorrected myopia would tend to make
    people more interested in close activities like reading and less
    interested in activities at a distance. Someone with uncorrected
    hyperopia might tend to be the opposite.

    I personally think that my interest in reading and lack of interest in
    sports, especially those involving balls, comes from high myopia not
    corrected until the 4th grade. Of course, the fact that my parents liked
    to read and didn't like any kind of sports might be a factor also! :)

    As I understand it, astigmatism causes blur at all distances, and the
    angle determines how to do the correction, but not the amount or kind of
    blur. Given that, I fail to see how different angles of astigmatism would
    have any effect on personality. I also fail to see how personality could
    cause astigmatism, or change the angle.

    The way that science works, is that you have a theory about cause and
    effect, and then see whether the evidence supports that. With no theory,
    there is no cause and effect, and no science.
     
    Dan Abel, Aug 22, 2003
    #12
  13. andrew Judd

    andrew Judd Guest

    Dan

    This is your opinion. So in this instance your opinion prevents you
    from seeing how personality could affect astigmatism.

    Lets put that aside and look at it scientifically.

    It has been shown that we look to different areas of our visual field
    to recall different memories. Generally it is upwards and to the
    left or right if we want to remember something and it is downwards if
    we want to forget something.

    Does that fit your opinions? To believe the above science you need
    to come up with some method whereby such a thing can be
    possible......or you just accept it is possible and has been measured.

    Myopia seems related to having opinions!

    To see normally we need to be able to see what is outside of our heads
    and not prejudge what our eyes sense. We then build a picture in our
    minds using our imagination and memory. We sense with our eyes but
    see with our minds.

    We know (from science) that astigmatism is variable. My own drifts
    around by about 5 or 10 degrees year to year.

    There is science that suggests that some individuals can produce
    astigmatism at will of several diopters.

    We can see that it is possible that unequal pulls on the muscles of
    the eyes could theoretically produce astigmatism. Strabisbus surgery
    often produces astigmatism.

    Laser surgery has found astigmatism very difficult to deal with.
    Little wonder if it caused by the mind rather than the eyes
    themselves.

    From science we know that mind and sight are intimately connected.
    Our eyes are connected both at the retinal level (left vs right in
    each retina) and muscularly to both left and right brains. Split
    brain research has shown that we dont have two minds but in fact two
    that cohabit our brains. We are literally in two minds. Head and
    heart if you will.

    It is therefore possible that astigmatism is caused by specific
    conflicts it the mind which result in unequal pulls of the muscles by
    each hemisphere.

    It appears as if our brains are connected together via the optic
    chiasm so that the attention of the dominant brain always directs the
    attention of the subserviant brain. Split brain patients have
    separate consciousness but do not markedly exhibit unnatural eye
    movement. In strabismus we find uncoordinated eye movement - even
    for apparently normal brains. The effect of the optic chiasm is
    powerful but it has exceptions.

    From Strabismus we know that it is possible even in adulthood to
    recover binocular vision (in some cases). So it seems that the left
    and right eyes can be operated independantly (somehow) in a normal
    brain.

    As we unconsciously use our eyes to get specific memories or refuse
    certain memories and do this in specific directions unconsciously it
    is not impossible that specific conflicts cause specific astigmatic
    angles to be produced.

    Sure it is far fetched......it does sound hard to believe.....but that
    does nto mean it is not true.

    Science has shown that if you stand on the right hand side of a person
    you are arguing with you are more likely to be believed that if you
    stand in any other position.

    Does that fit your opinion?

    Science is about investigating what is, rather than denying what could
    be because it does not fit our own opinion.

    My own data seem reliable.....the patterns are very strong.....I need
    more time to confirm Dr Kaplans work......his work is already
    done.....I am only confirming his work in order that I can believe it
    myself.

    I can believe it though.....it makes sense.

    If you are astigmatic and want to let me know your angles for each eye
    I can produce a profile as to how you experience astigmatism in your
    daily life.

    These patterns are very strong.

    Cheers

    Andrew
     
    andrew Judd, Aug 23, 2003
    #13
  14. andrew Judd

    andrew Judd Guest

    (Otis Brown) wrote in message
    Otis I am not interested in the variation in the
    autorefractor.....hopefully this will remain constant......If the
    autorefractor itself varies it would be a major problem.

    Andrew
     
    andrew Judd, Aug 23, 2003
    #14
  15. andrew Judd

    andrew Judd Guest

    Andrew judd said
    Actually I am not sure about the ennervation to the
    muscles.....Possibly the muscles of each eye are only controlled by
    one hemisphere.....that makes more sense.

    However muscular tension is commonplace in the human body and the eyes
    can be no different.

    Andrew
     
    andrew Judd, Aug 23, 2003
    #15
  16. andrew Judd

    Dr Judy Guest

    snip

    We also stick out our tongues when concentrating and cannot blink and think
    at the same time. Stephen Pinker's books about neurobiology offer some
    interesting evolutionary explanations for these observations. But what have
    they got to do with predicting personality by measuring astigatism? Who has
    measured, scientifically, the personality/astigmatism connection?
    Yes, perception is a cortical function.
    Could you support those statements with science? The only muscle that could
    produce astigmatism is the ciliary muscle, and likely is the one involved in
    voluntary astigatism increases. I have seen many strabisbus surgery
    patients; yet to see one whose astigmatism changed post surgery.
    Laser surgery deals with astigmatism very effectively.
    Our eyes are not connected to each other at the retinal level. Information
    from the two eyes is combined beyond the optic chiasm in the brain. Eye
    muscle motor control is from a single central point, there may be damage in
    the motor nerve pathways to each eye, but the control is central.
    Mood, stress etc affect the brain, but I have never seen any evidence that
    it affects eye muscles.

    http://apu.sfn.org/content/Publications/BrainBriefings/bb_humor.htm

    http://apu.sfn.org/content/Publications/BrainBriefings/brain_depression.html
    The corpus callosum, not the optic chiasm, contains the fibers that connect
    the two hemispheres. The optic chiasm does not control eye motor response.
    If fact, the optic chiasm doesn't control or effect anything, it is a
    crossroads for nerve fibers on their way to the processing areas.
    We have known for decades that there are some brain cells that respond to
    the right eye, others that respond to the left eye and others that respond
    to both eyes.

    http://apu.sfn.org/content/Publications/BrainBriefings/visual_development.html

    It would be very unlikely that an adult who had never had binocular vision
    as a child would recover it. I don't see what the existance of binocular
    vision (neurons that respond to information from each eye) has to do with
    showing the independance of each eye or with the personality/astigmatism
    connection.
    snip

    You first need to show that eye movement causes astigmatism to change, then
    that eye movement in different directions causes different kinds of
    astigmatism, then that specific emotions cause specific eye movements
    before you can begin to speculate on a personality/astigmatism connection.
    If any of the first three are not true, the rest of your hypothesis falls
    apart.

    The first one will give the most trouble, people do not notice their vision
    blurring as the eyes move around during normal life.

    snip
    When you publish your results, we will believe them. Asking us to believe
    before the science is done and getting annoyed because we won't believe
    before the evidence is in is a little much.

    For more information about how the brain works, in layman language, see:

    http://brainconnection.com/library/?main=bbhome/main

    snip

    Dr Judy
     
    Dr Judy, Aug 23, 2003
    #16
  17. andrew Judd

    andrew Judd Guest

    I can see you have gone to some length to show me your point of view
    which is great!

    I will follow up on the links you have given and let you know what i
    find out.

    You have misunderstood a few things i was saying
    Roberto Kaplan has collected empirical evidence of this by comparing
    personality with prescriptions.

    That to me is the beginning of Science. It would be interesting to
    see the kind of studies that you expect me to do, but done to refute
    Kaplans work.....I am not aware of any being done.

    My own 'work' with, so far, a tiny sample of 4 people supports Kaplans
    work 100%.

    I dont consider myself to be an idiot. If you think I am an idiot
    then there is no point in talking to me. Rather than be hostile it
    would be better for me if I could see your strictly controlled studies
    which refute Kaplans work. That to me would be more friendly. So
    far I dont see yours or anybody elses studies and only have Kaplans
    and my supporting testimony.

    But i dont want to be unfriendly about this.....I just want to be
    clear about things.

    What you say is interesting to me......I will dig out some references
    for the impressions I have gained above.....my own astigmatism of
    course is just my own opticians data......are you saying that
    astigmatism is not variable? I think not.
    You misunderstand me. The computed corneal and lenticular astigmatic
    components are very often , when applied to the cornea, insufficient
    to correct the astigmatism.....there are plenty of papers about
    describing the difficulties involved. Presumably you are unaware of
    this? Do you do laser surgery yourself? Perhaps I am completely
    wrong that i have already read these papers, but i think not.
    I am not sure what you are understanding here.

    Clearly our eyes cannot be connected together at the retinal level in
    a physical sense but.....

    The vision of the left retina of the left eye goes to the left
    hemisphere and the vision of the left retina of the right eye goes to
    the left hemisphere to produce the left eyes field of view. That was
    the point i was making.
    What do you mean by a central point? A single tiny point without the
    ability to differenitate and independantly control the eyes?

    That cannot be true. Each eye is somehow very accurately pointed at
    a target independant of what the other eye is looking at (at the micro
    level) and each eye vibrates around this point with its own saccades.
    At the micro level these saccades would be shown to be independant of
    the other eyes saccades.....the attention of each eye is the same or
    similar but what they actually do is not identical. Even the focus
    of each eye is independant as you can prove by looking at a nearby
    object sideways.

    I can introduce evidence that the eyes are independant, and describe
    this in such a manner than any optician can check out for
    themselves....

    Here is that evidence. To believe it you will have to do your own
    studies thougth.

    Many people who wear glasses or contacts have a degree of strabismus.
    Often for example the right eye points either out or in. Sometimes
    this becomes far more noticable without glasses than without glasses.

    In my own case without glasses my right eye points outwards. I have
    no binocular problems that have ever been brought to my attention
    ever. This seems to be the case for many other people i know - even
    though who have deviating eyes with lenses. Presumably there is a
    degree of eccentric fixation that is tolerable in these people - even
    though the amount clearly varies they consider they can see normally.

    What is interesting is if I am not interested in what is happening
    around me then without glasses my right eye points away from me, by
    varying amounts.

    However when i am strongly interested.....say for example having a
    very antimated conversation.....this eye does not point
    out......clearly suggesting to me that my behaviour and my eye
    movements are related.

    It would be simple for you to test this out with other people who have
    the same eye movements as me. And then report back what you find.
    To get the person to be interested does require you find something
    they are passionate about.....very passionate......it does require
    that you not be judging of them and allow them free expression.....so
    that they feel it is ok to express themselves to you.....they can be
    fearful but they must express what they truelly feel to you. Often
    the person will be very angry as they express what they are truelly
    feeling. When the eye points back out they are resigning themselves
    to not changing what they are angry about.

    Doing this kind of work is very different to the experiences of what
    most opticians are trained or emotionally prepared to do. I have
    spent years and years learning about these aspects of myself and
    others. Yes I am a lay person but i am not an idiot :)

    Well there is plenty of evidence around that stress and emotion affect
    the dark focus of accommodation. That has been well studied. That is
    just one example of mood affecting the eye muscles.
    Again i am not sure what your understanding is here. When the corpus
    callosum is severed the eyes function harmoniously together with
    almost no noticeable exceptions (there are some very occassionally).
    Clearly eye coordination is not happening via the corpus callosum if
    this is what you are suggesting.

    What does happen after is is cut is that the left brain cannot see
    what the right brain can see if it is not in the same half of the
    field of vision (for that eye) . Plenty of studies have been done
    based on this effect in split brain patients.

    Even with the corpos callosum severed the hemispheres can still
    communicate together but only by sensing.....what the other sees and
    thinks is completely unknown to it.
    Well is it? What is its purpose then? what happens when it is
    damaged? Is it just a simple junction box as you suggest? I seem to
    recall you telling me last year that the optic chiasm linked the eye
    movements together. I do feel it was you who said that Dr Judy.

    I does not really matter.....somehow the eye movements are linked
    together quite strongly but not immutably strongly...the linkage can
    be altered even in normal brains.

    Each eye is capable of independant action. Possibly one muscle for
    left movement could conflict with another muscle for right
    movement....that is my belief.

    The Astigmatic personality correlates are all about very strong
    conflicts.

    The person might be very patient for example in many aspects of
    life......yet in other areas they are very stubborn inflexible and
    impatient.....a clear conflict in their way of being......this is
    expressed as 180 degrees in either eye.
    Unlikely yes but it is well known it can happen. what is your point
    here? Are you saying it is not possible and does not happen?
    Should we not be interested in finding out why these unusual fusions
    occur? What about the rare cases of myopia improving? should we
    assume we know why this happens? Assume based on our opinions? This
    is not scientific. Its the stuff of the dark ages.

    I don't see what the existance of binocular
    If the brain has separate areas to control the eyes then it is quite
    likely that mental strains within the mind can independantly affect
    the movements of the eyes. We see with our minds not with our
    eyes. We dont control the movements of our eyes directly but rather
    we control our attention.

    As I have suggested based on my experience it is possible for each eye
    to have independant attention......naturally mental conflicts can
    create competing attentions and when these are very strong.....as is
    the case with the astigmatic personality correlates there must
    inevitably be muscular conflicts too. I am not saying we understand
    how that can be, at this stage.

    I think we can agree that nobody understands how vision actually works
    at the moment?
    I dont really need to show much at all! I can already see that
    astigmatism is related to very strong personality conflicts such as
    stubborness or clash of will/surrender of will. There is no
    speculation on this! Just that you do not believe it.

    I have already spoken to a leading Brain researcher about strabismus
    and brain inbalance and he said he has already considered it and it
    was certainly worth progressing but he did not have time to do it
    himself. I am not going to say who this was by the way so people can
    pester him and he can feel betrayed or something that i have spread it
    around the internet he think it interesting.

    If you think it interesting make your own investigations. If you want
    to help me better understand these events then great! If your purpose
    is to make yourself look clever and me an idiot....... well......you
    can imagine how i would feel about that. Even and idiot might be
    upset to have that implied :)
    Well some people have claimed they can create astigmatism at
    will.......a few doctors have written about this over the years.

    As we both know, the eye is a bag filled with none solid material
    under pressure. Its tendency is to be spherical. lack of balanced
    sphericicity can come from a variety of possibilities. Natural
    growth......unlikely i think but possible.....IOM's or EOMs or some
    combination of these factors. For sure astigmatism becomes built
    into the eye over time. It is a structural problem.

    We know that any part of the bodies musculature can carry tension. So
    why should the eye conveniently be any different? Astigmatism does
    not tend to suddenly happen overnight.....even if it took incredibly
    subtle imbalances to cause astigmatism it still is possible that the
    EOM's could be responsible via subtle tensions and imbalances. For
    sure the EOm's are fantastically strong muscles just to move a wee eye
    around in its orbit but they have to be to accelerate the eye so
    rapidly.

    Of course you wont!!!!
    I am not that annoyed Dr Judy...:)

    I just think it is a bit far fetched to believe you will believe a
    word of what i say if it does not fit your own already firmly held
    opinion.

    However I am always interested in somebody who is prepared to listen
    to me and by and large you listening to me and you are being helpful
    in doing so. :)

    I feel things very strongly......so yes sometimes you push my buttons
    but that does not mean I am so very angry or that I dont like you.

    Cheers

    Andrew O:)
     
    andrew Judd, Aug 24, 2003
    #17
  18. andrew Judd

    andrew Judd Guest

    How about a truce?

    Interesting.....i dont have very high astigmatism......
    You mean objective.....these are real changes not subjective ones.

    Actually I am also very interested in pupil response......there is
    heaps of research to show the connection between large pupil and
    visual excitement.....surely one would expect some connection there
    with accommodation being similarly linked......so far other than dark
    focus studies which do show a big linkage i have not seen studies for
    amount of myopia vs level of interest....this sort of thing merits
    further study.

    These are the sorts of things I am interested in pursuing.
    I have already made a simple laser optometer.....it is too slow to use
    for my purposes.....I want to see readings far
    quicker......retinoscopy might be a better route - a far better route
    in fact and by the simplest but i cant get quick readings doing this
    unlike the auto refractor.

    Fair enougth then, but astigmatism without myopia is not such a major
    problem for most people......even fighter pilots can have
    astigmatism....I know one such man who has astigmatism.....he still
    flew military jets with it, has glasses but very rarely wears them.
    picky picky picky.....i assume you are a myope?
    Of course....even idiots know the eyes are not connected together :)
    Your understanding is way off here.......it is common for most myopes
    to have minor tracking problems.....the eyes do not accurately follow
    a pencil for example. Each eye tracks independantly.....but the
    overall movement is somehow linked together but is is not fixed
    together so that movements are identical........with slower movements
    the eyes do track correctly for these same people.

    Each eye has to point at an object so that the fovea of each is seeing
    the point of best vision......how can the eyes be locked together and
    still do this - quite impossible....they track independantly but are
    linked together for the gross movements......at the micro level they
    are not linked.

    Are you saying the saccades of each eye are identical......no way can
    this be true.
    As I clearly said....only when i dont wear glasses
    Dr Judy.....if i can move one eye and not the other what does that
    suggest to you? When i am wearing glasses I dont do this.
    In your opinion......
    Yes...i seem to recall that i did know this now I come to be reminded
    of it!
    Sure it is not common to see this.....however you have dozens of
    patients who have abnormal function of the eye and have strabismus.

    In childhood strabismus is easily, in time, curable for most
    children.....

    Childrens brains are more adaptable and flexible than the brains of
    adults but even adult brains are not fixed in concrete.

    Please try and reconcile this what i am saying.

    I think we need to move beyond what you may have read in a text book
    and try and use some common sense.

    If i can move only one eye at a time,,,,,,admittedly in special
    circumstances and not while wearing glasses it seems to offer evidence
    that a normal brain can move its eyes independantly sometimes.

    I mean....under your view how on earth does a growing body adapt to
    using its eyes accurately if the eyes cannot be independantly
    controlled (at a very low level in the brain beyond conscious control)

    Your view makes no sense at all. The human eye is capable of
    pointing in a huge variety of different directions......clearly each
    eye acts independantly at a very low level in the system. When we
    are tired or we are loosing our ability to keep our attention we get
    double vision.......our eyes point to what our minds are interested in
    looking at......it is not something we can control ourselves

    We can only control our attention....thinking of two things
    simultaneiously is generally very hard to do.....in a healthy mind -
    even for a woman!.

    The human mind can be aware of zillions of things but only sees one
    point of view best.....all other points of view are in the periphery
    of consciousness....in a healthy mind.
    LE -0.50 * 180 format
    And??? what is your point??

    My point is that an adult who has had life long strabismus can recover
    the normal use of their eyes. does it matter that 30 years
    previously they wore a patch etc etc.??
    ....the opposite in fact.

    Empirical.....Based on observation not theory......it is the basis of
    a great deal of science.....ie not theory driven but driven by what is
    observed.
    Agreed.....it is interesting speculation.....an interesting
    theory.....a theory that is part based on empirical evidence ...ie
    what is observed.
    I dont claim to be fully conversant of anatomy........nothing i have
    so far said seems so very incorrect.....a few errors perhaps but the
    basic premise remains valid and quite possible. By the way your
    links were ....popular science stuff....rather dissapointing.
    Well Kaplan OD has already published a book on the subject and I have
    a B.Sc. and you wont believe we have any credibility .....why would
    you believe others?.....there are plenty of well controlled studies on
    vision and personality.......based on opinion only they get
    discounted.

    Perhaps when you learn what empirical means you might see that my
    beliefs are not based on speculation as you seem so fond of telling me

    Andrew
     
    andrew Judd, Aug 25, 2003
    #18
  19. andrew Judd

    andrew Judd Guest

    Jan

    Almost certainly you are talking about a retinoscope here - never
    heard of a skiascoop....sounds double dutch to me!

    In its simplest form this can be done with a plain mirror with a hole
    drilled in it while the subject is lit from behind and above by a
    bright light.

    So such a method is easily within budget!

    Bedanks

    Andrew
     
    andrew Judd, Aug 25, 2003
    #19
  20. andrew Judd

    andrew Judd Guest

    No Jan! I completely agree with you....Scary maybe!

    The only reservation I have in using a retinoscope is:

    Do my subjects need to be perfectly refracted for the distance they
    are looking at before i can then ask them my questions?

    So.....

    If they are slightly myopic for this distance then i can see that if
    they become less so, my shadow will slow down or reverse but.....

    Can i easily tell if the shadow excellerates if they are myopic for
    this distance and become more myopic? Or are myopic and become less
    so?

    I believe that a skilled user can determine prescription to within at
    least a diopter without using trial lenses so the speed of the shadow
    must give a great deal of info.....or?

    I have not used a retinoscope before but am aware of the basic
    principal and how to find the astigmatism angles , myopia or
    hypermetropia.

    So I am wondering......what can this baby do!

    Of course one drawback I can see is that without an autorefractor or a
    qualified optician to use the retinoscope I am then stuck having to
    convince people i can use the damned thing!!!

    Getting an optician on my side would not be easy......they might worry
    their professional reputation could be reduced by them attaching
    themselves to far fetched and idiotic schemes........regardless of
    whatever merit the study might actually be seen to have.

    Cheers

    Andrew
     
    andrew Judd, Aug 26, 2003
    #20
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