The theory behind starburst (or other glare problems)

Discussion in 'Optometry Archives' started by Dan A, Mar 10, 2005.

  1. Dan A

    Dan A Guest

    Hello,

    I have been in a LASIK surgery and have been studying related knowledge to
    some extent. But so far I haven't found information on how starburst effect
    is formed in eye optics. What is the exact theory behind it and where can I
    study about it? Camera optics is ok too if information is more easily found
    in that area.

    To make the question clearer, I'm curious how one burst or arm or ray is
    formed, why is it in that particular position and not evenly 360 degrees
    around the object forming a solid field?
     
    Dan A, Mar 10, 2005
    #1
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  2. Dan A

    g.gatti Guest

    WOW

    GOOD QUESTION!

    have you noticed that NOBODY with perfect sight has this problem?

    Only people with glasses have that.

    Obviously the problem is not in the eye but in the mental strain of the
    imperfect sight AND the glasses.

    http://TheCentralFixation.com
     
    g.gatti, Mar 10, 2005
    #2
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  3. Dan A

    Dan A Guest

    have you noticed that NOBODY with perfect sight has this problem?

    Well, a person with perfect sight doesn't have problems with his sight.
    Glasses usually produce only minor glare distortion (compared to eye
    problems).
    The eye is a mechanical device with living tissue and a bunch of nerve
    cells. If the mechanical device is faulty, it will certainly be more
    difficult for the brain to translate the picture in the best possible way.
     
    Dan A, Mar 10, 2005
    #3
  4. Dan A

    g.gatti Guest

    sight.

    So what is the explanation for imperfect sighted people?

    Do you really believe in something physical?

    Then why it cannot be found?
    That's why glasses are not a solution, ever!
    way.

    What is the "mechanical device"?
     
    g.gatti, Mar 10, 2005
    #4
  5. Dan A

    Dan A Guest

    Do you really believe in something physical?
    Who says it cannot be found? I already know the answer to my question
    partly, but I need further information to fill the gaps. What do you think
    causes distorted vision then? The mind? And the optical system of the eye
    does not have a problem? Of course the mind is the most important part of
    the seeing process, but certainly if the eye is not well, the picture will
    be send to the brain imperfectly.
    So, do you have a refractive error which you can subconsciously correct with
    the mind? How many diopters?
    If you don't consider the eye as a whole a mechanical device, do you
    consider the cornea or the crystalline lens to be mechanical parts (well
    they're not totally mechanical, they are living tissue - but still they have
    very much the same qualities as if they were made of glass for example)?
     
    Dan A, Mar 10, 2005
    #5
  6. Dan A

    g.gatti Guest

    when you say THE MOST you need to understand THE VERY MOST ABSOLUTELY.

    now, even with this defective understanding of yours, THE MOST means
    that the mind has MORE part in vision than the eye... and still you go
    after these idiots doctor who treat only the eye MISTREATING IT and do
    not know anything about the rest?



    People are getting a cure from -23 D.
    I'm witnessing it and it is going very well.
    Slowly but unbelievable.
    example)?

    No quality at all like the glass, of course, all living and all
    SUBSERVIENT to the mind.

    Unless you understand this, you won't go anywhere.
     
    g.gatti, Mar 10, 2005
    #6
  7. Dan A

    drfrank21 Guest

    Sorry you got that nut case who responded to you.
    Starburst in post lasik patients is a higher order
    visual aberration usually due to corneal haze or
    induced by the flap. Usually seen with individuals
    with dilated pupils at night. Hope this helps.

    frank
     
    drfrank21, Mar 11, 2005
    #7
  8. Dan A

    Dan A Guest

    Sorry you got that nut case who responded to you.

    I must say that there may be some truth in what he says even it sounds
    totally nut.. I believe it hasn't been scientifically worked out how the
    glare problem exactly diminishes after LASIK surgery (but there is of course
    a scientifical explanation, it just hasn't been found yet). And this is what
    I'm most curious about. What changes when improvement occurs - is it the
    cornea, the pupil, the mind or what?
    Actually with LASIK, I don't think it's usually due to corneal haze or flap
    aberration. I think it is mostly because of refractive error at the edge of
    cornea.

    What I'm looking for is the theoretical explanation to optics, how exactly
    do the light rays refract. Obviously starburst differs from basic non-focus,
    but how?
     
    Dan A, Mar 11, 2005
    #8
  9. Dan A

    Dan A Guest

    People are getting a cure from -23 D.
    Well. As the picture absolutely away from anything recognizable at -23 D, I
    would say that it is impossible for the mind to calculate a real picture out
    of that. So, there has to be a drastic physical change in the eye. The three
    important parts are the cornea, the pupil and the crystalline lens. The
    crystalline lens even has muscles around it and the iris around the pupil is
    a muscle itself. In practice, this person would see better if the pupil was
    contracted and the crystalline lens got some miraculous power to extend to
    unnatural positions.
     
    Dan A, Mar 11, 2005
    #9
  10. Dan A

    Dan A Guest

    I think it is mostly because of refractive error
    A more accurate description: It is mostly because of refractive deviance at
    the edge of the optical zone of cornea. (Although the "badly" refracting
    area extends to the very edge of the cornea as well.)
     
    Dan A, Mar 11, 2005
    #10
  11. Dan A

    g.gatti Guest

    The girl can focus half a mm letter at 18 cm.

    What do you think?

    It is clear that the eye is turning back to its normal shape, being the
    elongation of the myopia simply disappearing over time.

    Also that same girl can focus at 5 feet a letter calibrated to be read
    at 10 feet.

    What do you think?
     
    g.gatti, Mar 11, 2005
    #11
  12. Dan A

    Dan A Guest

    It is clear that the eye is turning back to its normal shape, being the
    Yes, that is in a way the simplest solution if for example the person was
    born with a good sight but then the eye extended in shape. It just went
    back. What is the success rate at this Bates thing? If it's really low, then
    it can be that it doesn't have any effect in reality but the eye heals
    itself sometimes.

    As to looking at sun, I don't understand why it would help. Yes, certainly
    looking at light reduces the size of pupil which means that focus gets
    better and depth of field becomes so that you can see better near and far at
    the same time. That can make the illusion of looking at light helps if you
    don't realize it's just momentary. But like in ear, if you have too loud
    sound you will just destroy your cells eventually.
     
    Dan A, Mar 11, 2005
    #12
  13. Dan A

    g.gatti Guest

    Why low?
    It's 100% success.
    But you have to do it.
    And you cannot do it with glasses on.
    So first thing you have to discard glasses.

    certainly

    You speak as if you can understand things.
    You cannot understand.
    Just do it and it cures.
    To do it you have to discard glasses, otherwise it won't work and you
    cannot do it.
    far at

    Again you speak of things you do not understand.

    Just do an experiment.

    Lit a candle and look at it with a mirror so you can check the pupil
    size.

    You will see that if you look into the flame, the pupil contracts, even
    if the flame is very low.

    You do the experiment and then tell me.
    Now you talk to this girl who is a biologist, doctorate, and let her
    explain to you how he is curing her eyesight.

    Your discussion are just a show of ignorance of the facts.
     
    g.gatti, Mar 11, 2005
    #13
  14. Dan A

    Dr. Leukoma Guest

    Interesting problem.

    Yesterday I consulted with a patient whose chief post-LASIK complaint
    was starburst. He was undercorrected, and eyeglasses seemed to
    diminish all except the starburst. Subsequently, during the
    examination, I also discovered that he had some residual glare as well.
    His togographical maps were significant for decentered ablations. He
    was essentially looking through the bottom part of the treatment zones,
    which left some of the under-treated cornea within the pupillary
    aperture. The patient said that this explanation made sense, because
    he could make the starbursts go away if he tilted his head back, which
    caused the lower lid to obstruct the under-ablated areas. In wavefront
    language, coma may be the closest description of this type of
    aberration.

    Another illustration is that of an eye with simple myopic astigmatism,
    and how the image is distorted in an orientation corresponding to the
    axis of the astigmatism, and symmetrical.

    DrG
     
    Dr. Leukoma, Mar 11, 2005
    #14
  15. Dan A

    g.gatti Guest

    You may ask to your colleagues in the university about the BELL
    THEOREM.


    Perhaps there is something more behind your little "scientific" mind.



    How can you be so "relaxed" with the teaching of all the learned men
    who have simply destroied your eyesight so that you must depend on all
    sorts of drugs and lenses and whatever?
     
    g.gatti, Mar 11, 2005
    #15
  16. Dan A

    Dr. Leukoma Guest

    Interesting problem.

    I recall a case of a patient whose chief post-LASIK complaint
    was starburst. He was undercorrected, and eyeglasses seemed to
    diminish all except the starburst. Subsequently, during the
    examination, I also discovered that he had some residual glare as well.
    His togographical maps were significant for decentered ablations. He
    was essentially looking through the bottom part of the treatment zones,
    which left some of the under-treated cornea within the pupillary
    aperture. The patient said that this explanation made sense, because
    he could make the starbursts go away if he tilted his head back, which
    caused the lower lid to obstruct the under-ablated areas. In wavefront
    language, coma may be the closest description of this type of
    aberration.

    Another illustration is that of an eye with simple myopic astigmatism,
    and how the image is distorted in an orientation corresponding to the
    axis of the astigmatism, and symmetrical.


    DrG
     
    Dr. Leukoma, Mar 11, 2005
    #16
  17. Dan A

    Dr. Leukoma Guest

    The flap was symmetrical with respect to the pupil. The decentration
    wasn't. Also, the starburt was completely resolved with an RGP contact
    lens. So, with that considered, it probably isn't loss of transparency
    at the scar. However, flap fibrosis was clearly visible everywhere but
    the hinge on these Intralase-created flaps.

    DrG
     
    Dr. Leukoma, Mar 11, 2005
    #17
  18. Dan A

    Dan A Guest

    You may ask to your colleagues in the university about the BELL
    What does the Bell theorem have to do with vision?
    Do you realize that you talk really fanatically and you sound like you're
    trying to defend a religion or something? If the Bates thing should work,
    isn't it just a technique, nothing more, nothing less? And why is this Bates
    thing so commercial? Shouldn't information like this be simply free? And I
    myself don't have to take drugs or use lenses (pupil contractor would help,
    but at the moment I'm ok as is).
     
    Dan A, Mar 12, 2005
    #18
  19. Dan A

    Dan A Guest

    So first thing you have to discard glasses.

    For the record, I don't use glasses, my eyes are LASIK operated. But tell me
    how long time does a person with bad vision have to be without glasses - how
    quickly will the eye heal itself with the Bates method? If it's a long time,
    who can afford to be half blind for a long time?
    What ever method there is, if it works, it can be scientifically explained
    and it can be understood. Of course the operation of brain isn't fully
    understood yet (not even close), but certainly eye optics (or even the
    visual operations of brain) don't include anything out of this world.
    What is the point of this experiment? Yes, the pupil contracts when more
    light is coming in.
     
    Dan A, Mar 12, 2005
    #19
  20. Dan A

    Dan A Guest

    So, with that considered, it probably isn't loss of
    I think there can be about 3 layers of bad picture superimposed on the good
    picture. The worst may be the starburst layer. Similar (same blur diameter)
    effect, halo, is the same thing, just spread more evenly. The distorted
    layers may be caused by different physical problems. But the biggest problem
    is the refractive deviance at the edge of the optical zone. This happens
    even without decentration. The picture gets much better when aperture size
    is reduced (for example if looking down with tilted head).
    What is the explanation to this? Was it not resolved with other kind of
    contact lens?

    Does anyone know of any attempt to simulate LASIK operated eye optics? And
    the theory behind starburst, where should I ask or look for information
    about this in case the answer should not be found in this news group?
     
    Dan A, Mar 12, 2005
    #20
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