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Perfect Sight Without Glasses. William Horatio Bates
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isbn 4064066453718
Автор произведения William Horatio Bates
Жанр Математика
Издательство Bookwire
According to the current theory, atropine paralyzes the ciliary muscle and thus, by preventing a change of curvature in the lens, prevents accommodation. When accommodation occurs, therefore, after the prolonged use of atropine, it is evident that it must be due to some factor or factors other than the lens and the ciliary muscle. The evidence of such cases against the accepted theories is, in fact, overwhelming; and according to these theories the other factors cited in this chapter are equally inexplicable. All of these facts, however, are in entire accord with the results of my experiments on the eye muscles of animals and my observations regarding the behavior of images reflected from various parts of the eyeball. They strikingly confirm, too, the testimony of the experiments with atropine, which showed that the accommodation could not be paralyzed completely and permanently unless the atropine was injected deep into the orbit, so as to reach the oblique muscles, the real muscles of accommodation, while hypermetropia could not be prevented when the eyeball was stimulated with electricity without a similar use of atropine, resulting in the paralysis of the recti muscles.
As has already been noted, the fact that after the removal of the lens for cataract the eye often appears to accommodate just as well as it did before is well known. Many of these cases have come under my own observation. Such patients have not only read diamond type with only their distance glasses on, at thirteen and ten inches and at a less distance, but one man was able to read without any glass at all. In all these cases the retinoscope demonstrated that the apparent act of accommodation was real, being accomplished, not by the "interpretation of circles of diffusion," or by any of the other methods by which this inconvenient phenomenon is commonly explained, but by an accurate adjustment of the focus to the distances concerned.
The cure of presbyopia (see Chapter XX) must also be added to the clinical testimony against the accepted theory of accommodation. On the theory that the lens is a factor in accommodation such cures would be manifestly impossible. The fact that rest of the eyes improves the sight in presbyopia has been noted by others, and has been attributed to the supposed fact that the rested ciliary muscle is able for a brief period to influence the hardened lens; but while it is conceivable that this might happen in the early stages of the condition and for a few moments, it is not conceivable that permanent relief should be obtained by this means, or that lenses which are, as the saying goes, as "hard as a stone," should be influenced, even momentarily.
A truth is strengthened by an accumulation of facts. A working hypothesis is proved not to be a truth if a single fact is not in harmony with it. The accepted theories of accommodation and of the cause of errors of refraction require that a multitude of facts shall be explained away. During more than thirty years of clinical experience, I have not observed a single fact that was not in harmony with the belief that the lens and the ciliary muscle have nothing to do with accommodation and that the changes in the shape of the eyeball upon which errors of refraction depend are not permanent. My clinical observations have of themselves been sufficient to demonstrate this fact. They have also been sufficient to show how errors of refraction can be produced at will, and how they may be cured, temporarily in a few minutes, and permanently by continued treatment.
1. Certain substances have the power of producing dilation of the pupil (mydriasis) and hence are termed mydriatics. At the same time they act upon the ciliary body diminishing and when applied in sufficient strength completely paralyzing the power of accommodation thus rendering the eye for some time unalterably focused for the farthest point - Herman Snellen Jr.: Mydriatics and Myotics System of Diseases of the Eye, edited by Norris and Oliver, 1897-1900, vol. ii, p. 30.
2. In simple hypermetropic astigmatism one principal meridian is normal and the other, at right angles to it, is flatter. In simple myopic astigmatism the contrary is the case.; one principle meridian is normal and the other, at right angles to it more convex. In mixed astigmatism one principal meridian is too flat the other too convex. In compound hypermetropic astigmatism both principal meridians are flatter than normal one more so than the other. In compound myopic astigmatism both are more convex than normal, one more so than the other.
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