Eye, the organ of sight, by means of which visible objects are represented to the mind.
It would be deviating from our plan, to give a minute anatomical description of this most useful organ ; we shall, therefore, confine our attention to the necessary treatment of the eye, in a diseased as well as healthy state ; in order to ensure a sound sight, to the latest period of life.
The eye is extremely tender, and liable to a variety of diseases, the most common of which are the following:
1. The eye-lids are sometimes infested with tumors of different kinds, and more particularly the stye, which grows on the edge of the eye-lid ; is attended with heat, stiffness, pain ; and, unless proper means be taken, with suppuration. It is a kind of abscess, which, in general, may be removed by dis-cutient applications; but, should these prove ineffectual, a small emollient poultice ought to be applied, to induce a suppuration, after which the tumor will spontaneously heal. In case, however, it should net have the desired effect, a surgeon must open the stye wit he point of a lancet; when the matter will be discharged.
2. "Warts, and other tumors, which require the same treatment as when they arise on other parts of the body. But if, in extirpating-such excrescences, part of the eyelid should be corroded, the lips of the sore must be laid as nearly together as possible, and the matter hardening on if, frequently re-moved, without the application of any dressings: for these, however mild, will only irritate and inflame the ball of the eye.
3. The eye-lashes are, in some cases, so much inverted as to rub upon the eye, and thus produce pain and inflammation. This complaint arises from a variety "of causes, without a complete knowledge of which it would be dangerous to attempt any application. Persons afflicted with this, or any other disease in the , eye, ought without loss of time, to avail themselves of professional advice, or to consult an experienced oculist, who is able to ascertain the true source from which the disorder proceeds.
4. A protrusion of the eye, if it amount to a considerable degree, is attended with much deformity and uneasiness, arising not only from a large portion of the lining of the eve-lid being turned outwards, but also from too great an exposure of the pupil. If this defect proceed from an enlargement of the eyeball, or in consequence of a dropsical swelling, the affection of the whole system must be attended to, without applying any local remedies ; but, if it originate from the cicatrix of an old wound, or an abscess, it may be relieved by carefully dividing the skin, and taking the utmost precaution to guard against the effects of inflammation : such operations, however, should be performed only by skilful hands. - Lastly, if it be originally produced by the small-pox, scrophula, etc. or arise from old age, the eyes should be bathed daily with cold water, or with some astringent, and saturnine solution.
5. Specks are sometimes formed upon the whit part of the eye, out more frequently upon the cornea, or the transparent horny coat, which covers the sight. In the former case, they are seldom attended with much inconvenience; but, in the latter, they frequently cause either a partial or total blindness. Such specks are generally consequent to inflammation; and, if vision be materially impaired, it will be requisite to resort immediately to surgical assistance.
6. A membranous excrescence, called pterygium, frequently appears upon the white part of the eye, and often spreads over the cornea, in such a manner as entirely to destroy vision. It is either occasioned by external injuries, or arises from a general disease of the whole system, as in the scrophula, or scurvy, etc.; but inflammation is always the immediate cause. In this, as in the preceding complaint, the patient should not tamper with the delicate organ of sight ; as, by one injudicious application, that sense may be lost, beyond the possibility of recovery.
7. The eye is sometimes enlarged by an accumulation of the aqueous humour ; which occasions a sensation of fulness in the eye-ball, gradually impedes the motions of the eye-lids, renders vision progressively more imperfect, till the unfortunate patient can at length only discriminate light from darkness. As the disorder increases, the hall of the eye becomes greatly enlarged, and the cornea begins to protrude ; so that, if a puncture be not made, the eye will burst, and discharge itself. In the early stages of this disease, the sight may perhaps be preserved by proper treat-ment ; but we earnestly exhort all patients, if they feel the value of their eyes, to avoid those pernicious nostrums, vended under the name of collyria, eye-waters, etc.
8. Inflammation of the eye. See Inflammation.
9. Blindness. See vol. i. p. 285.
11. Cataract. See Gutta Serena.
12. Short sight, though it cannot be strictly considered as a disorder of the eye, is nevertheless a serious evil. Those who are naturally near-sighted, are seldom relieved from that defect, till they attain a certain age, when that uncommon rotundity which occasions it, gradually decreases. In order to remedy this inconvenience, they have recourse to eye-glasses, which, on certain occasions, are of real utility} but instead of using both eyes at the same time, or at least alternately, they absurdly close one, while they view an object through the glass with the other ; by which means they can only in-spect it sideways ; a practice that deserves severe censure, inasmuch as the eye which is not exercised, must necessarily become useless.— See Spectacles.
These remarks are equally applicable to those persons who can distinguish objects only at a distance ; for eye-glasses to them also become necessary, to enable them to behold more minute objects with greater precision.
Weak eyes are chiefly occasioned by residing in confined situations : hence so many persons, living in towns, complain of this misfortune, which can only be attributed to the want of a pure atmosphere, as well as to the confined circle of vision : - the rays of light being reflected from smooth walls, which dazzle the eyes, cannot fail to injure those organs in a very material degree.
Those parents, consequently, who have a just regard for the health of their children, cannot testify it more effectually, than by exposing them daily and frequently to the bracing influence of the fresh air ; and, if it become necessary to confine them in nurseries, instead of selecting the smallest and lowest apartment, the loftiest and most airy should be appropriated to that purpose. For a similar reason, infants ought to spend a considerable part of their time near the windows, where distant objects may attract their attention ; a practice which is highly conducive to the improvement of sight.
Those adults who are afflicted with weak eyes, should always burn two candles, placed in such a direction that their flame be neither too high nor too low; or rather make use of proper lamps : See vol. i. p. 432 ; and also, the article Lamps. - Persons of this description should never approach strong fires, nor live in hot rooms; for heat dissipates the natural moisture still remaining in debilitated eyes, so that it materially tends to weaken that organ, and at length induces total blindness. Rest, after long exertions, is very necessary and useful to the eyes, but the lids should never be too closely shut, as a continuance of that practice is very pernicious. Similar effects arise from a rude and frequent friction of these tender parts.
Few remedies for preserving the eyes are more refreshing and invigorating, than cautiously bathing them in cold water, three or four times in the day; the eye not being abruptly immersed, and the washing expeditiously managed. The drying of the eyes should likewise be carefully performed, les that organ be too much stimulated, and at length inflamed.
Eyes of Horses. - These are liable to a variety of diseases, which proceed either from a defluxion or rheum, or from some external injury.
If a defluxion be the cause of the malady, it will previously be necessary to ascertain, whether it arises from the eye itself, or from some other injured part, as, in the latter case, the healing of that part will generally cure the eye. In the former, it will be requisite to administer remedies which cool the animal's blood : with this intention, two ounces of Glauber's salts, and two drams of nitre, may be mixed, and given every day with his bran; but if he should loathe his food, an equal quantity of the liver of antimony may be substituted, till his appetite returns.
When the eye has received external injury, the following application is recommended : Take of hog's lard; the oil of roses; and of elder, equal parts ; and as soon as those ingredients are incorporat-ed over the fire, anoint the eye affected, which will soon recover its former energy. - Some horses have naturally weeping eyes, which emit a sharp, acrid humour. These,' however, may be easily cured, by washing or bathing them every day with brandy.
Eye-water for Horses. - Mr. Bradley recommends the following preparation, as being of singular efficacy in curing rheums in the eyes of this noble animal: Take four ounces of alehoof, or ground-ivy (not the creeping ivy), beat it in a marble mortar with the whites of six hard eggs, and add half a pint of clear white wine ; a quarter of a pint of rose-water ; sugar-candy and white vitriol, of each one ounce and an half;—beat them together with a pestle, that they maybe properly incorporated; then strew over them one ounce of pure salt; cover the mortar; place it in a cellar; and, after it has stood there rive or six hours, pour the whole into a clean bag of white serge, placing a vessel underneath to receive the liquor ; which must be afterwards preserved in a glass bottle. A little of this preparation is to be poured, every morning and evening, into the horse's eye.