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Home Medical and Vet Remedies, as Recommended by 19th and 20th century Doctors and Vets! |
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Home Medical and Vet Remedies, as Recommended by 19th and 20th century Doctors and Vets! |
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Weak SightThe vision of the natural eye includes an immense range, beginning at a point about five inches from the eye and extending to infinite distance, like that of the fixed stars. So long as the eye remains in its natural condition it can be employed for vision con tinuously upon objects situated anywhere within this range. If the individual become short-sighted or long-sighted to a considerable degree there occurs, after a certain time, an indistinctness of vision over some part of the natural range ; the sight becomes indistinct either for distant or for near objects. In most cases there occurs for some time before this indistinctness of vision some pain, either in the eyes themselves or in the forehead and temples. This pain increases if the effort to use the eyes be continued. There may result a severe headache, followed perhaps by sickness at the stomach, giddiness and palpitation of the heart. The symptoms are sometimes so severe as to inspire a belief that the patient is suffering from some disorder of the brain or of the stomach. Yet if the actual source of the difficulty be suspected and corrected, these symptoms, and with them the supposed disease of the brain, subside. A good example is related by Mr. Carter : " A young gentleman of good position, who was reading for honors at his university, suddenly broke down with symptoms which were attributed to some form of brain disease, and was advised to give up his studies and to go home. After a period of rest, being no better, he sought advice in London, where the opinion previously given was confirmed, and as a means of affording the most complete possible rest to his brain, he was advised to make a voyage to Australia and back. He did so and returned in the same condition. He was then considered to be incurable, was told that he must abandon a career which had been opened to him and a matrimonial engagement which he had formed. In a word his whole life was blighted. Ultimately he was brought to me, not from any idea that his eyes were at fault, but merely that I might examine their internal circulation in order to see whether this examination would throw any light on the state of the circulation in his brain. I found his eyes healthy but somewhat short-sighted, and on making inquiry into his symptoms, ascertained that they resolved themselves into simple inability to read. As soon as he took up a book he became giddy, and the giddiness brought on intense head ache, palpitation of the heart, and sometimes sickness at the stomach. M The case was of the simplest kind, the patient had never used spectacles, and up to a certain point he had been able to read well and easily. When he began to work for honors, and to read eight or ten hours a day, the muscles gave way ; and then, as the two eyes were no longer directed to the same point, the patient saw double/ This in its turn produced giddiness, and the giddiness produced headache and sickness by disturbing the circulation. The strained muscles which had once given way, became prompt to give way again when they were unduly called upon, and the grave view which was taken of the symptoms by medical men filled the patient with alarm; as soon as he tried to read the old troubles were brought back by fear and expectant attention. I assured him that he had no brain disease, tried to make him understand his condition, prescribed spectacles to correct his short-sight, and told him to wear them constantly and to read in them three times a day for half an hour at a time. He was to report progress in three weeks ; and at the end of that time he returned cured. He could read as much as he liked. He was going to be married the following week, and on returning from his wedding trip was to take up the career which he had fancied closed to him forever. All these pleasant anticipations were in due time fulfilled and the cure was permanent and complete. " The eyes may suffer in adult life from numerous causes, such as improper illumination, excessive use, exposure to cold, and diseased conditions of the body. There is considerable misapprehension as to the proper light required for the eyes. Sunlight is just as necessary and proper for the eye as food is for the stomach ; but the eye can be injured by excess as well as by deficiency of light, just as the stomach can be by excess or deficiency of food. The eyes may be injured by long exclusion from daylight, as occurs when they are bound up for a long time, or when colored glasses are worn. In such cases the eye acquires an unusual degree of acuteness so that the individual can distinguish objects in what others would regard as total darkness. If such eyes be restored to daylight, much caution must be used to prevent injury. A more frequent cause of injury to the eye is exposure to a dazzling light, especially after leaving comparative darkness. Many individuals have experienced serious impairment or even loss of sight by looking directly at the sun, or by watching an eclipse through a piece of glass which was not sufficiently obscured. After looking at the sun there often remains an appearance like that of a dark cloud, which becomes of a fiery color when the eyes are closed. Sometimes a permanent dark spot, corresponding to the position of the sun's image, remains in the eye. At other times this dark spot gradually spreads over a considerable part of the retina, so that the individual is threatened with total blindness. Prof. Arlt says that he saw three cases of this kind after the eclipse of the sun in 1851. Impairment of vision may occur likewise from the sudden reflection of bright sunlight into the eye by means of a mirror, as is often done by children at play. The reflection of the sun from the surface of snow or of the water has also occasioned serious injury to the eyes. Several considerations become evident from these facts. It is to be remembered that the position of the eyebrows and the arrangement of the lids is such as to protect the eyes from light which comes from above, but to leave them unprotected from that which comes up from below. Hence low windows are disadvantageous, unless provided with blinds which draw up' rather than down in order to shut off the light from the lower part of the window. Yet more difficulty is experienced in regulating artificial than natural light. This occurs not simply from the feebleness of many artificial lights, and from the fact that they are often but imperfectly shaded, but also because the artificial lights produce a larger percentage of heat than is derived from the ordinary daylight. Gas especially produces an excessive amount of heat in proportion to the light furnished. The heat has an injurious effect upon the eyes, since it dries the fluids which moisten their surfaces and predisposes to various inflammatory diseases of the eye. Various devices are employed to shut off so far as possible the heat rays which accompany the light from artificial sources of illumination. A common expedient consists in placing a bowl of glass containing water underneath the gas flame ; the water, while permitting most of the light rays to pass through it, absorbs a large amount of the heat. This absorption of the heat is still further increased if a little alum be dissolved in the water. Another device consists in surrounding the artificial light with blue glass. Since the heat rays are found chiefly with the red light, the blue glass, by intercepting all but the blue light, cuts off most of the heat. Another item of importance in the use of artificial light pertains to the position of the lamp. The ordinary lamp should be so arranged that the flame is a few inches higher than the eyes, since in this way the eyes are protected to a certain extent by the eyebrows ; it should also be placed a little to one side, preferably the left, in order that the light rays shall not fall directly into the eyes. It is always advisable to have but one source of illumination, whether this be natural or artificial. Thus the individual should so arrange his work and himself that the light falls into his eyes from only one lamp or gas jet ; by permitting it to enter from several sources the eye is more fatigued, not only because it receives an undue amount of light, but also because it is strained by the effort to see distinctly in the presence of so much light. So, too, when it becomes necessary toward evening to employ artificial light, the daylight should be excluded on the same principle. The effort to read when the individual is unsteadily moving, as happens in a carriage or in a railway car, is of course extremely trying to the eyes, and should be avoided. But first, if you want to come back to this web site again, just add it to your bookmarks or favorites now! Then you'll find it easy! Also, please consider sharing our helpful website with your online friends.
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