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causes, and the lens, which is naturally clear as crystal, becomes opaque.
It is untrue that the outer surface of the eye becomes flatter with advancing age, therefore manipulations, to restore what is not wanting in organs so delicate in structure that a rude push may be followed by perpetual darkness, should be avoided. The principal lens of the eye is situated behind the pupil, and is kept in its proper position by membranes finer than goldbeater's skin. These delicate membranes are liable to be ruptured by blows, falls, or other causes, as before said, and the beautiful lens may be totally destroyed."
Destructive opacity of the lens, or cataract, may be produced, without lacerating the membrane, by a mere interference with the circulation of vessels which supply them with blood; that these results take place is verified by our experience, as well as that of many eminent writers.
A case is related by a German oculist of one who was made totally blind in consequence of the fingers being playfully pressed upon the eyes by a companion from behind. In the endeavor to escape, his sight was instantly destroyed.
“It has been attempted to increase the rotundity of the eye by placing over it a wooden cup attached to an india-rubber bottle like a breast-pump. In the hands of a good juggler almost miraculous experiments are performed with cups and balls. It is not surprizing, therefore, that new arrangements should produce new wonders. The machine, described by Captain Marryat, for altering the disposition of the individual by exhausting cups placed over protuberances of the skull, has not yet been turned to practical account. Some self-styled professors will, it is presumed, shortly take this matter in hand, and advertise instruction by which any change of temper may be affected. There is a tradition, at least as old as the Talmud, that the eyes are strengthened by drawing the finger gently across the eyelid in a horizontal direction.”
“ Ex-President John Quincy Adams, who was affected with an obstruction of the tear passage, employed this method to get rid of the accumulated fluid. This ancient practice was revived, being brought into notice by the practice of this illustrious statesman. The obsolete theory that the eye
flattens as age approaches was also again revived, and it became a business to advertise instructions and lessons for kneading the eye into shape with the fingers. For the very moderate sum of ten dollars the telltale spectacles might be laid aside, and ancient ladies and gentlemen see and read with all the ease of a girl in her teens. The ten dollar professor, if we may believe the newspapers, met with marvelous success till improvements were advertised in the manner of the performance."
“Such harmony prevails in animate beings that all the functions of the body are performed without consciousness of the existence of the organ by which these functions are effected. When the lungs are in a healthy condition the play is not perceived by the possessor. The organs of sight and hearing perform their duty without observation or notice, and gain nothing by having our attention directed to them. We cannot assist in the performance of their functions."
Dr. Wallace further remarks: “The circulation of the deli cate organization of the eye may be interfered with even by medicines. Dr. Currie relates, that owing to the effect of strychnine and veratrine, the capsule of the lens was dislocated. Others have noticed the occurrence of cataract after the operation of medicines. It is no uncommon consequence of the so-called “aconitum trick,' a hazardous experiment with aconite. If even medicine taken in the stomach will derange the eye, how careful should we be with regard to manipulations of every sort.” (Chicory produces most unpleasant results.)
The above remarks are taken from unpublished manuscripts now in our possession. The bad effect of rubbing the eye open, or of frequent wiping when in a condition of derangement, will be readily appreciated after reading the foregoing sentences.
WHEN THE EYE SHOULD REST.
When the eyes complain, the remedy is repose. They are best rested, not by darkness, but by a change of employment. Employ them upon distant and agreeable objects. The old method of shutting up ophthalmic patients in a dark room was full of evil, producing the very mischief that it was designed to remedy. A single indiscretion is often fatal to useful vision. A patient sometimes says, “I must finish this work or complete this manuscript." Milton said, “I will go on if I am blind in consequence.” He did go on and became blind. Few of us are so near immortality as he was, and can so well afford to go on. An eminent and judicious oculist in New York the other day pointed out to us a single figure in a very large engraving. He said that the sight of it always made him sad. The engraver had, after years of labor, still a single figure to complete. Serious symptoms caused him to apply to this gentleman, who told him that he must stop. He said, “I must finish that last figure." He did finish it, and is now led by a boy around the streets. One hour of railway reading under certain circumstances, may be the cause of fatal impairment of vision. (See Author's experience, Sight and Hearing, p. 69.) It is a dangerous practice, and never safe. Eye work is peculiarly injurious after severe illness, or when the body is in a debilitated condition. When overheated, or very much fatigued, or immediately after a full meal, it is more economical to rest. Students should avoid procrastination at other hours, so as not to be forced to work at improper moments. If the indications of nature are regarded she will plainly say stop in most instances, but not always.
Near-sighted, ambitious young people are peculiarly exposed to fatal overuse of the eyes, or to the dangerous experiment of increasing the power of the concave glass in order to continue with comfort their excessive labors. We have several patients under treatment at the present moment whose history would furnish illustrative examples.
The following is a remarkable illustration of the manner in which a single act of indiscretion may be followed by permanently serious results. In the London and Edinburgh Philosophical Magazine for May, 1859, there is an account of sudden loss of the power of distinguishing colors, produced by overtaxing the eyes. A sea-captain, who was in the habit, when time hung heavy on his hands, of occupying it by working at embroidery, was one afternoon engaged upon a red flower, and being anxious to finish it prolonged his labor until twilight came on, and he found it difficult to select the suitable colors, To obtain more light he went into the companion way, and there continued his work. While thus taxing his eyes his power of distinguishing colors suddenly vanished. He went on deck, hoping that an increase of light would restore his vision, but in vain. From that time to the present, more than ten years, he has remained color blind.
The use of tobacco is frequently productive of the impairment of eyesight among students. The sedentary habits of the student render him unfit to resist the injurious effect of this drug upon the nervous and glandular systems. That tobacco frequently produces amaurosis can be proved by the most credible authority. We have, this very month, been called to prescribe for a case of amaurosis evidently produced by the use of tobacco. This patient has improved by simple abstinence. He was such an inveterate smoker that he rose in the night to indulge in his pipe. Such cases are not unfrequent. This subject is considered at length in the volume before referred to.
The want of sufficient sleep is often the cause of the failure of eyesight. No one can spend so profitably one third of his time as in sleep. It preserves the mind from insanity, and secures nervous equilibrium. Few scholars should do with less than eight hours. It is improper to continue severe studies quite up to the hour of rest. The hour preceding sleep should not be spent in study.
INDIGESTION AND STIMULANTS.
Indigestion is a frequent cause of disturbed vision. The reflecting reader needs no proof of this. The stomach has been called the second nervous center. All dyspeptics experience difficulties in the use of their eyes during times of peculiar derangement of the stomach. The scholar must keep on good terms with this organ if he would employ his eyes to the best advantage. There are many in the ministry who are not less dyspeptic than Timothy, and might find a prescription among the teachings of Paul. On this subject says an eminent writer:* “In the present state of public opinion on this subject there is comparatively little danger of the abuse of alcoholic drinks on the part of educated men, and especially of those called by their position to set an example of temperance. We are not so sure that, so far as the health of the individual is concerned, the error in many instances is not on the other side. The majority of those exposed to diseases of the eye are persons whose ordinary state of health would be called, in State-street, somewhat under par.” However, ever since Solomon sung of him who has redness of eyes,' inflamed optics have furnished the most indubitable evidence of excess.
* Dr. Bethune, Bibliotheca Sacra, April, 1855.
The great Boerhaave remarks that “to say that any one article of food is wholesome or unwholesome, without knowing the constitution of the one for whom it is intended, is like a sailor saying that the wind is fair or unfair without knowing the port whither he is bound." Indigestible articles variously affect different persons; shell-fish seems oftenest to produce a direct influence upon the eyesight. Beer, the German ocnlist, after alluding to the effects of indigestion, says: “The daily practice of every oculist is filled with coincident experience.”
Mental disquietude, though probably impossible to prevent in this world of care and anxiety, is often a cause of deranged vision. It is a great art, which very few, alas ! ever learn, to be always tranquil in this perturbed and disquieting world. Study and thought make men sensitive, and peculiarly exposes them to unrest.
SOME EYES BETTER THAN OTHERS.
It should never be forgotten that some eyes, without regard to constitutional peculiarities, will endure more wear and tear than others. Beer, the great German author so frequently referred to, observes :* “The power of the eye increases in proportion to the lightness of the eye, and, on the contrary, diminishes in proportion to its degree of blackness. For example, dark blue eyes support much less expenditure of vision than the gray, and brown eyes can endure much less straining than the dark blue.” He further remarks, that of a hundred men who have black eyes, scarcely one found who is altogether contented with his sight. This rule has exceptions; but it furnishes a valuable guide with
* Pflege gesunder and geschwächter Augen.