my glasses have barrel distortion

Discussion in 'Glasses' started by Morten S, Jan 26, 2004.

  1. Morten S

    Morten S Guest

    i got a new pair of glasses last week, they are -4.0 on both eyes.
    beeing a contact lense user for years, the first thing I noticed with the
    glasses was the extreme barrel distortion.
    My optician adjusted the glasses and this made them a tad better...but the
    distortion is still there.

    is it possible to make -4.0 glasses WITHOUT any barrel distortion?
    dont the glasses-makers have tools that checks this before handing out their
    glasses to their customers?
     
    Morten S, Jan 26, 2004
    #1
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  2. First, I am not a vision professional. My opinion, however, is that you will
    get used to the distortion. That is, the mind and brain can compensate for
    your distortion.

    I have heard of experiments with glasses designed to invert the image formed
    on the retina. Supposedly, after a while, that was no longer a
    disorientation problem. I have had something like that happen to me.

    Bill
     
    Repeating Rifle, Jan 26, 2004
    #2
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  3. Morten S

    Jan Guest

    Morten,

    The barrel distortion is caused by the distance between the lens and the
    pupil.
    A lens ( your contactlens) with the aperture (your pupil) at the same place
    (or nearly to keep it simple) gives no distortion as you mentioned.
    A minus lens (your glasses) placed before the aperture (your pupil) at a
    greater distance gives a barrel shaped distortion.
    And yes, a plus lens gives a pillow shaped distortion when wearing glasses.

    It is not possible to make glasses without this distortion but you could try
    to position your glasses as near as possible to the eyes.

    If you wear your glasses constantly, you get used to this distortion (your
    brains wil fix the job), but if you change regularly between your
    contactlenses and the glasses you might keep the distortion problem.

    Maybe this answer helps,

    Jan (normally Dutch spoken)
     
    Jan, Jan 26, 2004
    #3

  4. Look what this man says: YOUR BRAIN WILL FIX THE JOB!!!


    Now, if the brain can fix jobs, why cannot fix imperfect sight?

    It can fix it.

    --
    Please visit
    http://www.stores.ebay.it/juppiterconsultingrishi
    and you can buy a replica of the Original Dr. Bates book
    "Perfect Sight Without Glasses"
    and if you are interested, join the group
    http://health.groups.yahoo.com/group/PerfectSight/
     
    Rishi Giovanni Gatti, Jan 26, 2004
    #4
  5. Morten S

    CLEFER Guest

    Interested in your reason for switching.
    I have recently gone the other way but need both, but I do not get distortion..
    Will you be trying to use both?
     
    CLEFER, Jan 27, 2004
    #5
  6. Morten S

    Morten S Guest

    I use contacts when im out in public and glasses at home...
     
    Morten S, Jan 28, 2004
    #6
  7. Morten S

    Otis Brown Guest

    Dear Morten,

    There are many OD who love to give you astigmatism
    "correction".

    That is your "barrel distortion.

    Go back and ask for "spherical" lenses.

    If he will not do it, please post his "reasons".

    [Or "rationalizations" depending on how you
    look at it.]

    Best,

    Otis
    Engineer
     
    Otis Brown, Jan 30, 2004
    #7
  8. Morten S

    Jan Guest

    Otis,

    In earlier messages posted here you mentioned your knowledge about
    photographic cameras.
    On of the known facts in photography is the distortion "barrel'' or the
    opposite "cushion" due to the position of the aperture and the position of
    the principal plane of the lens(system).
    The optic industry made special design lenssystems wich have the aperture at
    the same place as the principal plane and then there is no "'barrel" or
    "cushion" distortion.
    It is about spherical lenses Otis, not toric ones.

    Jan (normally Dutch spoken)

     
    Jan, Jan 30, 2004
    #8
  9. Morten S

    Otis Brown Guest

    Dear Jan,

    Yes there is a difference between "barrel" and astigmatism.

    But when a layman looks through a lens with substantial
    astigmatism cut, and rolls the lens and sees the
    distortion of distant objects produced by that lens,
    he tends to call it "barrel". Under that circumstance,
    you must use HIS discription to talk to him.

    Best,

    Otis

    ******

     
    Otis Brown, Jan 31, 2004
    #9
  10. Morten S

    Otis Brown Guest

    Good point. Exact language -- depends on fundamental
    definitions.

    If in science I wish to establish that the natural
    eye is dynamic, I am not going to use ORGANIC DEFECT
    to describe the refractive states that I am measuring.

    The difference is in the assumptions of the words
    you are using.

    Pure and fundamental science is profoundly different
    that "health care".

    Hope you have the sophistication to understand that
    difference.

    Best,

    Otis
     
    Otis Brown, Jan 31, 2004
    #10
  11. Morten S

    Jan Guest

    Otis,

    Where did you read that the OP wrote astigmatism?
    Where did you read, he rolls his lens?
    He only mentioned minus 4 and the term "barrel" when he wears his glasses.
    The story which you try to (sell) tell me was not his.
    Otis again you are trying to make smoke to cover up your mistake.
    I would say you are wrong and you do not want to admit it.
    Keep by the facts and use the right definitions Otis if I may advise you.
    And if you are not familiar with the matter, may I advise you to keep out.

    Jan (normally Dutch spoken)


     
    Jan, Jan 31, 2004
    #11
  12. Morten S

    Otis Brown Guest

    Dear Friends,

    If you have a spherical lens, you can check
    this by looking at distant objects and
    turning the lens around the axis.

    If the lens has serious astigmatism cut,
    you will see the objects expanding or
    "distorted". It is very difficult to
    describe this, but it is interesting
    to check.

    The man in question complained of "headaches",
    and I suggested checking his lens in this
    way.

    What other words you wish to describe this
    effect is up to you.

    Best,

    Otis
    Engieer




     
    Otis Brown, Feb 1, 2004
    #12
  13. Morten S

    Ann Guest

    Weird pincushions where you come from. But I'll take your word for
    it... and just try to keep it in mind.

    Ann
     
    Ann, Feb 1, 2004
    #13
  14. Morten S

    Jan Guest

    Dear Friend,
    Put on some reading glasses (plus, your favorit) Otis, the OP did not use
    the word ''headaches" and was not complaining of it either, he was just
    complaining about the distortion and he used the excact term "barrel"
    You are the one who wish to use other words.
    Making smoke Otis to cover up your wrong answer/suggestion I would say.


    Jan (normally Dutch spoken)


     
    Jan, Feb 1, 2004
    #14
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