What Glasses Do to Us

Discussion in 'Optometry Archives' started by Lelouch, Aug 7, 2009.

  1. Lelouch

    Lelouch Guest

    [...]

    By W. H. Bates, M.D.

    'On a tomb in the Church of Santa Maria Maggiore in Florence was found
    the following inscription: "Here lies Salvino degli Armati, Inventor
    of Spectacles. May God pardon him his sins." ' [1]

    The Florentines were doubtless mistaken in supposing that their fellow
    citizen was the inventor of the lenses now so commonly worn to correct
    errors of refraction. There has been much discussion as to the origin
    of these devices, but they are generally believed to have been known
    at a period much earlier than that of Salvino degli Armati. The Romans
    at least must have known something of the art of supplementing the
    powers of the eye, for Pliny tells us that Nero used to watch the
    games in the Colosseum through a concave gem set in a ring for that
    purpose. If, however, his contemporaries believed that Salvino of the
    Armati was the first to produce these aids to vision, they might well
    pray for the pardon of his sins; for while it is true that eyeglasses
    have brought to some people improved vision and relief from pain and
    discomfort, they always do more or less harm, and at their best they
    never improve the vision to normal.

    That glasses cannot improve the sight to normal can be very simply
    demonstrated by looking at any color through a strong convex or
    concave glass. It will be noted that the color is always less intense
    than when seen with the naked eye; and since the perception of form
    depends upon the perception of color, it follows that both color and
    form must be less distinctly seen with glasses than without them. Even
    plane glass lowers the vision both for color and form, as everyone
    knows who has ever looked out of a window.

    That glasses must injure the eye is evident from the fact that one
    cannot see through them unless one produces the degree of refractive
    error which they are designed to correct. But refractive errors, in
    the eye which is left to itself, are never constant. [2] If one
    secures good vision by the aid of concave, or convex, or astigmatic
    lenses, therefore, it means that one is maintaining constantly a
    degree of refractive error which otherwise would not be maintained
    constantly. It is only to be expected that this should make the
    conditions worse, and it is a matter of common experience that it
    does. After people begin to wear glasses their strength, in most
    cases, has to be steadily increased in order to maintain the degree of
    visual acuity secured by the aid of the first pair.

    That the human eye resents glasses is a fact which no one would
    attempt to deny. Every oculist knows that patients have to "get used"
    to them, and that sometimes they never succeed in doing so. Patients
    with high degrees of myopia and hypermetropia have great difficulty in
    accustoming themselves to the full correction, and often are never
    able to do so. The strong concave glasses required by myopes of high
    degree make all objects seem much smaller than they really are, while
    convex glasses enlarge them. These are unpleasantnesses that cannot be
    overcome. Patients with high degrees of astigmatism suffer some very
    disagreeable sensations when they first put on glasses, for which
    reason they are warned by one of the 'Conservation of Vision' leaflets
    published by the Council on Health and Public Instruction of the
    American Medical Association to "get used to them at home before
    venturing where a misstep might cause a serious accident." [3]

    All glasses contract the field of vision to a greater or less degree.
    Even with very weak glasses patients are unable to see distinctly
    unless they look through the center of the lenses, with the frames at
    right angles to the line of vision; and not only is their vision
    lowered if they fail to do this, but annoying nervous symptoms, such
    as dizziness and headache, are sometimes produced. Therefore they are
    unable to turn their eyes freely in different directions. It is true
    that glasses are now ground in such a way that it is theoretically
    possible to look through them at any angle, but practically they
    seldom accomplish the desired result.

    The difficulty of keeping the glass clear is one of the minor
    discomforts of glasses, but nevertheless a most annoying one. On damp
    and rainy days the atmosphere clouds them. On hot days the
    perspiration from the body may have a similar effect. On cold days
    they are often clouded by the moisture of the breath. Every day they
    are so subject to contamination by dust and moisture and the touch of
    the fingers incident to unavoidable handling that it is seldom they
    afford an absolutely unobstructed view of the objects regarded.

    Reflections of strong light from eyeglasses are often very annoying,
    and in the street may be very dangerous.

    Soldiers, sailors, athletes, workmen and children have great
    difficulty with glasses because of the activity of their lives, which
    not only leads to the breaking of the lenses, but often throws them
    out of focus, particularly in the case of eyeglasses worn for
    astigmatism.

    The fact that glasses are very disfiguring may seem a matter unworthy
    of consideration in a medical publication; but mental discomfort does
    not improve either the general health or the vision, and while we have
    gone so far toward making a virtue of what we conceive to be necessity
    that some of us have actually come to consider glasses becoming, huge
    round lenses in ugly tortoise-shell frames being positively
    fashionable at present time, there are still some unperverted minds to
    which the wearing of glasses is mental torture and the sight of them
    upon others far from agreeable. Most human beings are, unfortunately,
    ugly enough without putting glasses upon them, and to disfigure any of
    the really beautiful faces that we have with such contrivances is
    surely as bad as putting an import tax upon art. As for putting
    glasses upon a child it is enough to make the angels weep.

    Up to about a generation ago glasses were used only as an aid to
    defective sight, but they are now prescribed for large numbers of
    persons who can see as well or better without them. The hypermetropic
    eye is believed to be capable of correcting its own difficulties to
    some extent by altering the curvature of the lens, through the
    activity of the ciliary muscle. The eye with simple myopia is not
    credited with this capacity, because an increase in the convexity of
    the lens, which is supposed to be all that is accomplished by
    accommodative effort, would only increase the difficulty, and this, it
    is believed, can be overcome, in part, by alterations in the curvature
    of the lens. Thus we are led by the theory to the conclusion that an
    eye in which any error of refraction exists is practically never free,
    while open, from abnormal accommodative efforts. In other words, it is
    assumed that the supposed muscle of accommodation has to bear, not
    only the normal burden of changing the focus of the eye for vision at
    different distances, but the additional burden of compensating for
    refractive errors. Such adjustments, if they actually took place,
    would naturally impose a severe strain upon the nervous system, and it
    is to relieve this strain—which is believed to be the cause of a host
    of functional nervous troubles—quite as much as to improve the sight,
    that glasses are prescribed.

    It has been demonstrated, however, that the lens is not a factor,
    either in the production of accommodation, or in the correction of
    errors of refraction. Therefore under no circumstances can there be a
    strain of the ciliary muscle to be relieved. It has also been
    demonstrated that when the vision is normal no error of refraction is
    present, and the extrinsic muscles of the eyeball are at rest.
    Therefore there can be no strain of the extrinsic muscles to be
    relieved in these cases. When a strain of these muscles does exist,
    glasses may correct its effects upon the refraction, but the strain
    itself they cannot relieve. On the contrary, as has been shown, they
    must make it worse. Nevertheless persons with normal vision who wear
    glasses for the relief of a supposed muscular strain are often
    benefited by them. This is a striking illustration of the effect of
    mental suggestion, and plane glass, if it could inspire the same
    faith, would produce the same result. In fact, many patients have told
    me that they have been relieved of various discomforts by glasses
    which I found to be simply plane glass. One of these patients was an
    optician who had fitted the glasses himself and was under no illusions
    whatever about them; yet he assured me that when he didn't wear them
    he got headaches.

    When glasses do not relieve headaches and other nervous symptoms it is
    assumed to be because they were not properly fitted, and some
    practitioners and their patients exhibit an astounding degree of
    patience and perseverance in their joint attempts to arrive at the
    proper prescription. A patient who suffered from severe pains in the
    base of his brain was fitted sixty times by one specialist alone, and
    had besides visited many other eye and nerve specialists in this
    country and in Europe. He was relieved of the pain in five minutes by
    the methods recommended by this magazine, while his vision at the same
    time became temporarily normal.

    As refractive abnormalities are continually changing, not only from
    day to day and from hour to hour, but from minute to minute, even
    under the influence of atropine, the accurate fitting of glasses is,
    of couse, impossible. In some cases these fluctuations are so extreme,
    or the patient so unresponsive to mental suggestion, that no relief
    whatever is obtained from correcting lenses, which necessarily become,
    under such circumstances, an added discomfort. At their best it cannot
    be maintained that glasses are anything more than a very
    unsatisfactory substitute for normal vision.

    [1] Nuova Enciclopedia Italiana, sixth edition.

    [2] Bates: Imperfect Sight of the Normal Eye, N. Y. Med. Jour., Sept.
    8, 1917.

    [3] Lancaster: Wearing Glasses, p. 15.

    ____

    Better Eyesight
    A monthly magazine devoted to the prevention and cure of imperfect
    sight without glasses
    Copyright, 1920, by the Central Fixation Publishing Company
    Editor—W. H. Bates, M.D.
    Publisher—Central Fixation Publishing Co.
    $2.00 per year, 20 cents per copy
    342 West 42nd Street, New York, N. Y.
    Vol. III - July, 1920 - No. 1
    ____

    [...]
     
    Lelouch, Aug 7, 2009
    #1
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  2. Lelouch

    Otis Guest

    You are correct:

    This is what a -3 diopter lens does to the refractive STATE of a sub-
    population of fundamental eyes.

    (As objective science.)

    Scroll down and look at the "Blue Tint" model of the eye's response.

    http://vision.berkeley.edu/wildsoet/myopiaprimer.html

    Science best,



     
    Otis, Aug 8, 2009
    #2
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  3. Lelouch

    Neil Brooks Guest

    Then don't put a -3d lens on a macaque ... if it doesn't need one.

    If you DO (because, for example, you're as bone-ignorant as Otis),
    then just get the macaque to stop wearing them for a few hours a day
    and all will be well.

    Otis?

    You're an idiot.
     
    Neil Brooks, Aug 8, 2009
    #3
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