Our Eyes, and How to Take Care of Them: V

INFLAMMATIONS OF INTERNAL PARTS OF THE EYE.

A BRIEF reference to a few points will show how suicidal is the course often pursued, in neglecting disease of the important internal structures of the eye until their vitality is wholly destroyed and recovery of vision hopeless.

Some of the most serious of these changes are attended with little pain, and perhaps give warning of their progress only by diminished sight. When pain occurs, as in the cases of acute inflammation, it differs from the smarting or itching sensations accompanying most of the forms of external inflammation, and has a deep-seated aching character, often extending along the nerves in the neighborhood of the eye, and sometimes more severe in the forehead and temples than in the eye itself. Any such pain, therefore, especially if accompanied by dimness of sight, should receive immediate attention, as a warning of impending mischief.

As might be supposed, most of the remedies which prove useful in the treatment of inflammations of the external membranes of the eye are not at all adapted to affections of the internal parts, and can only be hurtful if applied.

INFLAMMATION OF THE IRIS.

This curtain, stretched across the interior of the eye, and from which it takes its color, blue, hazel, etc., is frequently the seat of inflammation. Generally this is attended with pain, extending to the brow or even to the whole of that side of the head, and usually more severe at night. The eye is often quite red, especially around the cornea, but in some cases there is little to attract attention to the eye. There is usually a copious flow of tears, but little thick mucous discharge.

The source of danger lies especially in the tendency to closure of the pupil by adhesion of its edges to neighboring parts. The thickened iris lies in contact with the crystalline lens, and the lymph thrown out from it, similar to the material which unites the edges of ordinary flesh-wounds, forms deposits which cement the margin of the pupil to the lens behind it and often completely fill its area. This misfortune may be avoided by timely treatment, the iris and lens being kept from contact with each other till the inflammation subsides. This is of great importance to the actual and prospective safety of the eye. If adhesions have already formed they may sometimes be detached, while still recent, by the use of remedies ; but if neglected they become firmly fastened, and can only be separated by surgical means.

Even slight adhesions increase the danger in case of future attacks of the disease ; but where the pupil has become entirely closed immediate surgical interference is necessary, to prevent a slow, destructive process resulting from pressure of the accumulating fluids behind the iris which can no longer find their way through the pupil.

Strong light and much use of the eyes should be avoided during the attack.

Persons of rheumatic constitution are liable to repeated visitations of iritis, which may occur at longer or shorter intervals. They should be careful to give prompt attention to the earliest symptoms, — slight pain, or dimness, or soreness on moving the eyeball,—as a prolonged attack may often be averted if the eye is at once placed under the influence of suitable remedies.

GLAUCOMA.

One of the diseases most absolutely fatal to vision if neglected, or if inefficiently treated, is glaucoma. It is most frequent in women, usually occurs after the middle period of life, and often follows physical or mental depression resulting from fatigue in watching with sick friends or grief in mourning their loss.

The pain in acute attacks is agonizing ; but it is often felt so much more severely in the nerves in the vicinity of the eye than in the globe itself, that these symptoms are frequently mistaken for facial neuralgia, and, notwithstanding the loss of sight, the primary seat of the disease is overlooked. The eyeball becomes hard, the cornea loses its sensibility, so that it may be touched with a probe without causing pain, the iris is pushed forward and the pupil dilated by the overcrowding of parts behind it, and all vision, even the perception of light, may be lost within a few days. There is often very little redness of the eyeball. These symptoms now and then subside for a time, to return after a longer or shorter interval with renewed force.

The attack is often preceded by a necessity for rapidly increasing the strength of the glasses worn for reading, and by an appearance of rainbow colors around the light on looking at a lamp in the evening, or of a fog or white sheet thrown over objects in the daytime.

On examination with the ophthalmoscope the entrance of the optic nerve, if still visible, shows a cup-like depression, a result of the extreme pressure within the globe. As the disease goes on, the transparent internal parts grow cloudy, so that the optic nerve can no longer be seen, the globe becomes of a stony hardness, the pupil is enlarged to the utmost, the iris is thinned by pressure, the lens is crowded forward until it lies against the cornea and takes a sea-green color, and hopeless disorganization ensues in all the tissues. The pain may continue during all these changes, or it may subside at an earlier period.

The only known remedy for this disease is the early performance of what is termed iridectomy, — an excision of a portion of the iris, — before the morbid changes have continued long enough to crush out the visual power and spoil the eye by their fatal pressure.

The results of this operation, the greatest triumph of modern ophthalmic surgery, seem almost miraculous ; it at the same time removes the extreme tension and puts an end to the unhealthy action which gave rise to it ; and a sufferer, one or both of whose eyes had become blind, obtains instant relief from the intense pain, and regains more or less quickly his lost vision. But to be complete, the relief must be speedy; too long compression of the delicate tissue of the retina destroys its powers.

AMAUROSIS.

Prior to the invention of the ophthalmoscope the term “ amaurosis ” was applied to loss of sight arising from sundry obscure conditions of the deeper-seated parts of the eye. Most of these are now distinguished as resulting from various changes, and are designated according to the structures affected ; and, as now understood, amaurosis implies disease in or behind the optic nerve, excluding such loss of sight as results from inflammation of the choroid or retina, separation of the retina, etc. Many cases, formerly considered hopeless amaurotic disease, are now found by the ophthalmoscope to belong to a more hopeful class of affections, capable of relief.

DISEASES OF OTHER ORGANS MANIFESTED IN THE EYE.

Not the least among the wonders revealed by the ophthalmoscope is the detection of diseases of other and distant organs by an examination of the internal parts of the eye. This has become possible, and the appearances indicating degeneration of the kidney can be as positively distinguished from those denoting certain changes in the brain, or from the structural alterations caused by diseases originating in the eye itself, as any of the most evident external manifestations of disease, as, for instance, those of small-pox and scarlatina can be discriminated from each other. The knowledge thus obtained will doubtless become more and more available in the explanation of phenomena which have hitherto been obscure, and aid in the successful treatment of disease.

CATARACT.

Cataract consists in a loss of transparency in the crystalline lens or its capsule. Cloudiness of the cornea, the result of ulceration, is quite a different thing, though such opacities are often supposed to be cataract.

When children are born with cataract, or it is developed early in life, as also in cases where it has resulted from a blow or wound of the eye, the cataract is usually soft and of a whitish or bluish-white color. When caused by a hurt it is formed only in the injured eye; but when not the result of an accident it generally appears sooner or later in both eyes.

Soft cataract may be removed, with little risk, by an operation ; but it is safer, in many instances, to operate by such a method as will require considerable time for the subsequent absorption and disappearance of the opaque lens, rather than to attempt its immediate removal.

The larger number of cataracts are found in persons beyond middle life; the disease affecting those of every condition and occupation, without apparent relation to the amount or nature of the use they may have made of their eyes. It is probably a result of modifications in the nutrition of the lens, causing it to become opaque, just as the hair becomes white in some persons with advancing age. Like these changes in the hair, it is often hereditary.

The progress of the cloudiness, which gradually shuts out perception of objects, varies greatly in different cases. This circumstance, and the fact that the vision may often be temporarily improved by palliatives, has allowed charlatans to claim that they have cured cataract without operation. But this pretension, often made, is as often falsified by the steady increase of the abnormal changes.

Sometimes the existence of cataract is accidentally discovered upon closing one eye, when it is found that vision in the other is nearly gone. In other instances a slight confusion of vision attracts attention to the eye in the very early stages of cloudiness.

Persons affected with cataract often see better in a dim light, at twilight, or on cloudy days, and perhaps find themselves suddenly unable to see on going into a bright sunlight. They should therefore be careful, when coming out of church or other places into a broad daylight, not to make mistakes in their judgment of distances and thus be liable to falls.

It is an error to suppose that there is no help for old people who become blind from cataract. The operation for its extraction from the eye is generally successful in restoringvision, — farmore so than could have been expected, considering the exceeding delicacy of structure of the eye, — and it can be done without pain, and usually involves only a brief confinement. Persons who are in their usual health, however aged they may be, whose eyes are not otherwise diseased, may therefore submit to an operation with confidence and hope.

NATURAL AND ARTIFICIAL LIGHT.

Of all the requisites for a comfortable use of the eyes, none is more important than a favorable and sufficient light ; and perhaps none is oftener neglected. Many persons read while lying down, giving more thought to comfort in the positon of their bodies than to whether the light falls in such a direction as is adapted for easy vision. Many school-rooms are so arranged as to favor only the teacher, whose desk is between the windows, while a flood of light falls full on the faces of the pupils, whose eyes have no protection against the strong glare.

Such a position as will allow the light to fall over the shoulder upon the book or paper is best in reading or writing, especially in the evening, the book being also so held that the eyes are not exposed to a direct reflection from the pages.

When artificial light is used, it should be steady and abundant. Far more harm is done by too little than by too much light when the eyes are used for reading, sewing, and similar avocations, and we may well rejoice in the advent of better means of illumination than were possessed by our ancestors. Tradition tells us that tallow-candles and pitch-pine splinters enlightened the eager youthful studies of some whom our country has ranked high among her honored names, but we are more fortunate in having for our “midnight oil ” the German student’s-lamp, the bright gas-jet, or the clear flame of kerosene.

A soft, steady light, such as is given by a student’s or a carcel lamp, is perhaps the perfection of artificial light; yet we may regard gas or kerosene as good enough for all practical purposes, if used in sufficient quantity and with burners which do not flicker.

Henry W. Williams, M. D.