In simple astigmatism, on looking at the accompanying astigmatic chart with each eye separately, certain lines in the defective meridian seem very much blurred, while those at exact right angles appear clear and black. This furnishes a test for astigmatism, since to the normal eye the lines appear of equal distinctness and clearness. Astigmatism is a very common ocular defect.

The Mechanism of Eye-strain.—Comparatively few eyes are perfect. Far-sighted or astigmatic eyes can secure perfect vision by means of accommodation. By constant strain on the ciliary muscle, the crystalline lens is so increased in curvature as to exactly counterbalance the optical defect of the eyes.

Healthy eyes should do their work without the consciousness of the owner, and this is a safe test as to the kind and amount of work demanded of them.

Perfect rest for the eyes is impossible in the waking state—distant vision represents rest for the eyes and near vision exertion.

Near work is the chief cause of near-sightedness. Distant vision should alternate with near work, and in near work the object should not be brought nearer to the eyes than 12 inches.

The Local Symptoms of Eye-strain.—There may be a sense of fatigue in the eyes after reading for a short time, and this may be followed by a constant sense of discomfort in the eyes, which is increased on using them, and which may be accompanied by severe pain in the back of the head. There is a sensitiveness to light, and inflammation of the eyelids and conjunctiva. There may be twitching of the eyelids, and in extreme cases difficulty in keeping the eyes open on account of drowsiness. The eyes may smart, itch, or burn, and continually “water.”

As the trouble becomes more pronounced, reading for a short time may be followed by a blurring of the type, and finally the lines may run together. There is a constant sense of the eyes feeling for the lines, and, perhaps one of the first things to call attention to the condition of the eyes may be the losing of the lines in reading.

The general or reflex symptom of eye-strain is headache, which frequently takes the form of migraine. This is increased on reading, sewing, riding in the cars, etc. The headache is usually over the region of the temples or just above the eyes, but it may be on the top of the head or at the base of the skull.

Vision is so fundamentally related to all the brain functions that eye-strain, or anything which interferes with normal sight, may cause the most varied disturbances of bodily functions.

The Prevention of Eye-strain.—Persons whose work necessitates much ocular labor should vary their duties with intervals of rest. In continued reading or sewing it is well to desist at short intervals and fix the gaze on some distant object, and to frequently close the lids.

Lace work, very fine needle work, working on black goods, reading very fine print, or print on an inferior quality of paper, or attempting to read in a dim light, are all a severe tax on the eyes, and should be avoided, as they are certain to cause them permanent injury.

Defective vision is so common in school-children, it is so often present without being suspected, and so much harm is done to the eyes and the general health of the individual before it is discovered, that there should be a compulsory law requiring the examination of all school-children; and, again, before boys and girls enter the normal schools and colleges.

Clear vision gives clear judgment; defective vision in its various manifestations gives different warps and bents to the mind of their unfortunate possessors.

Veils.—The wearing of veils is responsible for not a little deterioration of vision, particularly when they are thick or dotted. Unless the meshes of the veil are very large, it holds a layer of impure air close to the face, so that the wearer is breathing vitiated air. It hinders clearness of vision, because the external world is viewed through a narrow lattice.

The best veil for the eyes is one with a single mesh, either without dots, or the dots so far apart that none shall come over the eyes.

Protection of the Eyes from the Glare of the Sun.—In very hot weather the eyes should always be so protected that the rays of the sun do not shine directly into them. This protection may be afforded by the brim of the hat or by a parasol. At the sea-shore, or on an ocean voyage, where the glare of the sun is constant and particularly trying, the eyes should be protected by wearing slightly tinted smoked glasses.

Artificial Lighting.—The main sources of artificial lighting are kerosene, gas, and electricity. The principal questions of importance are the quantity and quality of the light, its steadiness, the vitiation of the atmosphere by the products of combustion, and the expense; also the proper arrangement of the light.

Kerosene is the most extensively used means for artificial lighting. The principal objections are—the heat, the trouble of filling and keeping the lamps in order, and the danger of explosion and fire if upset; the odor and the great vitiation of the atmosphere.

The modern lamp gives a brilliant light, and if properly shaded by a slightly bluish chimney, so as to absorb the excess of yellow rays, it is very satisfactory.

Illuminating gas, as furnished in cities, has a great excess of yellow rays, which are very injurious to the eyes, and the vitiation of the atmosphere is very considerable. Gas-light is modified by the Argand and Bunsen burners. Of these, the Bunsen burner, a patented composition burner, heated to incandescence, is the best. It gives a white light, resembling daylight, and, under proper adjustment, a far greater volume than any other burner. It is not so hot, does not consume as much gas, and so there is less vitiation of the atmosphere. It is intensely brilliant, and must be shaded by ground glass or a proper shade.

Electricity gives the very best light, with a minimum amount of heat and vitiation of the atmosphere. For individual use 16-candle power is sufficient.

The lamp-shade should be opaque, of a dark-green color, and lined with a white, reflecting surface. Transparent lamp-shades, especially when patterned, are always bad, whatever their color; because of the different degree of illumination thrown upon the work, the light is irritating to the eyes.

Hygienic Precautions in Reading and Sewing.—There should be free access of open daylight. Near the window is obviously the best place for working, and the seat should be so selected that the window is to the left of the worker. This prevents the work from being shaded by the hand, and protects the eyes from being fatigued by the light falling directly into them.

Any room will have too much light into which the sun shines directly. Even if the worker’s face is not turned directly toward the sun, yet the light reflected from the book or other work will be so intense as to be dazzling. The softest and most pleasant light to work by is the diffused light from the northern sky. An excess of light may be easily regulated by a shade.

Reading.—Very fine type should always be avoided, it is a very unnecessary strain on the eyes, as are also books printed on a poor quality of paper with improper spacing. The paper should be unglazed.

Length of Line.—The length of the printed line should not be more than 4 inches, nor less than 2¾ inches; that is, not more than 10 or less than 7 centimeters. If the line is too long, the effort to find the succeeding line is too great. If, on the other hand, the line is too short, the lateral movements of the eye are so frequent that the muscles concerned in these movements soon become fatigued.

The position of the reader should be sitting upright, with the back toward the light, which should fall over the left shoulder, and the book held nearly on a level with the eyes. The book should be held at a distance of about 12 inches from the eyes. The light should be on a level with the head or slightly above it. In desk work, a shade should always be worn to protect the eyes.

Reading in the recumbent position is a pernicious habit, and is particularly bad when convalescing from an illness or when very tired.

Reading in carriages or cars is injurious to all eyes, but especially so to myopic eyes; because of the constant jolting, the distance between the type and the eyes is continually changing, necessitating the frequent and abrupt adjustments of accommodation; besides, the illumination is apt to be very poor. Reading in a dim light or the twilight is also very bad for the eyes.

Sewing and embroidery require the most trying ocular labor and the best conditions for illumination. Working on black goods by artificial light should be absolutely forbidden.

Injuries to the Eyes.—The most common injuries to the eyes are the entrance of small particles of dust, cinders, steel filings, etc., into the conjunctival sac, or into the substance of the cornea. Frequently, with the aid of a little winking, the tears wash away these foreign substances, but if the substance lodges in the lining membrane of the upper or lower lid, or is imbedded in the cornea, it may be necessary to resort to other means in order to remove them.

The lining membrane of the lower lid is brought into view by simple tension of the lower lid downward by one finger. If the offending particle is not seen, the upper lid should be averted. This may be easily effected by the fingers alone. The patient is told to look down, the edge of the upper lid and the lashes are seized by the thumb and forefinger of the right hand, and the lid is drawn at first forward and then downward away from the eye, then upward over the point of the thumb or forefinger of the left hand, which is held stationary on the lid and acts as a fulcrum. The foreign body should be removed with the handkerchief, but, if it is imbedded, it may be necessary for a competent physician to remove it.

The habit of opening the eyes when dipping the face into a basin of water, or when diving, produces congestion and inflammation of the conjunctiva.

Symptoms and Treatment of Conjunctivitis.—The eyes may be blood-shot and the lining membranes of the lids intensely red. There is a sense of irritation about the eyes and an intolerance of light, with a constant sense of discomfort. The sensation produced is that of having sand in the eyes. The eyes are heavy, and tire after using them for a short time.

The best treatment for acute conjunctivitis, which is so often caused by the penetration of dust or other foreign bodies into the conjunctival sac, is the application of cold water. A folded handkerchief is wrung out of ice-water and laid on the closed lids. It must be changed every few minutes, so that it shall not become warm; two cloths are necessary. When the acute symptoms have begun to abate, the patient will no longer find these applications grateful, and they must be discontinued.

For chronic conjunctivitis hot applications are the best. For these, one teaspoonful of fine table salt may be dissolved in a pint of hot water, or two teaspoonfuls of boric acid may be used instead; the last named is a mild antiseptic. The boric acid dissolves very slowly, so that it is well to prepare enough in the morning for the entire day. One tablespoonful of boric acid may be put into a quart bottle of hot water, and be well shaken from time to time, until there is a perfect solution.

When ready for use, half a pint may be heated, poured into a tumbler, which is then placed in a basin of hot water; this latter serves as a water-bath to keep the solution in the glass hot. The application should be made with a rather thick wad of absorbent cotton or a piece of fine cheese-cloth. The absorbent cotton should be picked up with all the water it will hold, and be placed over the closed eyes just as hot as can comfortably be borne, and held there until it begins to cool, when the procedure should be repeated. The two eyes can be treated simultaneously. These hot fomentations should be kept up for ten minutes, and be repeated four times a day.

Trachoma.—This malady, of which so much is heard now, is another name for granular conjunctivitis or granular lids. The affection is very contagious. It comes on slowly, and is frequently accompanied by redness and an appreciable degree of secretion in the early stages. Presence of secretion or of interference of the vision should always attract attention.

Strict precautions must be taken that the patient’s handkerchief, towel, and wash-basin are not used by other members of the family. Further, the other members of the family should bathe their eyes several times a day with a solution of boric acid.

Styes.—Styes are a very painful species of small boils that generally form on the edges of the eyelids. They are apt to appear in succession. Certain persons are liable to them if the system is run down from general causes. Like boils in other parts of the body, they give evidence of impaired nutrition.

Hot fomentations of boric acid solution will sometimes abort them if used early. If pus has formed, the stye must be opened by an incision parallel to the edge of the lid. This should not be attempted by any one except a physician.

Color-blindness.—As a rule, about 4 per cent. of males and about one-half of 1 per cent. of females are color-blind. The part of the color sense that is most often deficient is that for green and red.

Cataract.—This is a disease in which the crystalline lens or its capsule, or both, lose their transparency and become opaque. Eventually total blindness is the result. Senile cataracts appear after the forty-eighth year. The only remedy for the disease is the surgeon’s knife.

Functional Nervous Disorders.—Evidences of sound health are: first, individual adaptability or capacity of the individual to easily adapt herself to extremely opposite conditions of existence; second, endurance, or the capacity to do a considerable amount of mental work for a short time without suffering fatigue, or to be able to quickly recover from the fatigue; third, to be able to control the emotions; fourth, to be able to resist morbific influence; that is, the capacity on the part of sound organs of excretion to quickly eliminate all poisons from the system.

The signs of debility are just the reverse: first, deformity, obesity, or leanness; second, personal inadaptability, that is, when physical or mental discomfort is caused by such slight provocations as change of food, clothing, or climate; third, lack of endurance, so that a long rest is required to repair the fatigue incident to slight exertion; fourth, lack of control of the emotions; fifth, a proclivity to morbific influences, so that the individual succumbs to every contagion or miasm that she encounters.

Nervousness is a disease of civilization, coupled with overwork and indoor life. The more complex the environment in which the individual finds herself, and to which she must adjust herself, the greater the demands made on the nervous system.

The extreme dryness of our climate, together with the great variations of temperature between winter and summer and the rapid fluctuations of temperature, predisposes to nervous disorders.

Headache.—Headache is a symptom rather than a disease, but there is no symptom which requires more careful investigation of its cause than that of headache. It occurs at all ages, but is most common from ten to twenty-five years and from thirty-five to forty-five years. Women suffer from headache more than men, in the proportion of about three to one. Headaches are most common in the spring and fall of the year and in the temperate climates.

Causes of Headache.—These may be classified into those in which the blood is at fault; reflex causes; various nervous disorders; and organic diseases.

The blood may be impoverished, as in the case of anemia, where there is a deficiency in hemoglobin; but by far the most frequent cause of headache is where the blood is disordered, as in gout, rheumatism, kidney diseases, diabetes, and the infectious fevers and malaria.

Among the more common reflex causes are eye-strain, especially errors of refraction; disorders of digestion, particularly constipation; and pelvic disorders, as in inflammation of the pelvic viscera.

Functional diseases of the nervous system causing headache are overwork, neurasthenia, hysteria, epilepsy, and neuritis.

Among the most common of the organic diseases is arteriosclerosis; other diseases are meningitis and brain tumors.

Symptoms.—The pain is often dull in character and rendered worse by stooping; the location of the pain depends on the cause of the headache. The most common variety is over the forehead or eyes. In eye-strain the pain may either be in the front or back of the head. In indigestion, the pain is most frequently over the eyes, but it may also be on the top of the head. In anemia the pain may be either frontal or diffuse. In pelvic disorders the pain is generally at the base of the brain, though it is sometimes in the top of the head.

Neuralgic headaches are generally characterized by sharp paroxysmal attacks, located in the temporal regions, and associated with pain in other parts of the body. It is perhaps most frequently caused by anemia.

In hysteria the headaches are characterized by a circumscribed pain—it has been likened to the driving of a nail into the head.

In migraine the pain is paroxysmal and intensely severe; it is frequently caused by some poison in the blood, as in autointoxication, due to failure of proper regulation of the bowels, also by pelvic disorders.

Treatment.—The treatment is constitutional, and is based on the removal of the cause. First, there should be a regulation of the diet, a free evacuation of the bowels, and their proper regulation. In every case of headache there should be an examination of the urine. Often there is some congestion of the kidneys where it is least suspected. If the headache is persistently made worse by reading or sewing, the patient should be referred to a competent oculist. An inquiry should always be made into the condition of the menstrual function, backache, and leukorrhea. Any marked disorders here will necessitate a gynecologic examination.

For the immediate relief of migraine, the patient should go at once to bed and drink a glass of hot water; sometimes a cup of hot tea gives great relief. No food should be taken for from six to twelve hours, according to the severity of the case. The room must be kept dark and quiet and the head high.

A strip of prepared mustard leaf, 5 inches wide by 8 inches long, should be cut, and a piece of cheese-cloth, 6 or 8 layers thick, should be folded the same size. The cheese-cloth is then wrung out of hot water, and the mustard leaf is quickly dipped into the same. The cheese-cloth is placed on the back of the neck, between it and the mustard leaf. The clothes should be kept dry by a folded napkin. In this way the mustard may be kept on from six to eight minutes, until it begins to burn and the skin get red. If left on too long, the mustard may produce the most painful kind of a blister. When taken off the neck, the mustard may be put on over the stomach.

The medicinal treatment must be directed by the physician, but a perfectly safe prescription, and one which may be kept on hand, is the following: Take of sodium bromid, 15 grains; of essence of peppermint, 10 drops; and of water a sufficient quantity to make 1 dram. Mix well. The dose may be repeated in three hours if necessary. This prescription should be put up by a good druggist, in a three-ounce quantity. Sometimes relief is afforded by 1 teaspoonful of the aromatic spirits of ammonia, taken in four tablespoonfuls of water, and this is about the right quantity of water to take any liquid medicine in. At night 2 grains of calomel should be taken, so that the patient shall not be disturbed through the night, and it is not so apt to cause nausea as when taken through the day.

Neurasthenia or Nervous Prostration.—This disease first saw light in the United States, and was christened by Beard as an American disease that was absent from no household in which the inhabitants used their brains. It is certainly much more prevalent in this than in any other country. Americans scarcely treat their bodies with more consideration than their automobiles; they put on high pressure and speed them to the utmost. Add to the high pressure under which we live that other fact of heredity, that many persons are born with unstable nerve-cells, and may be nervously bankrupt, and it is not difficult to understand that 50 per cent. of Americans are suffering in some degree from lowered nerve tone.

Causes of Neurasthenia.—All classes of men and women who use their brains severely, and who have seasons of excessive anxiety and responsibility, are subject to neurasthenia. We have seen that fatigue was caused by the accumulations of toxins in the body, due to muscular activity, but these toxins may also be caused by intellectual overwork or anxiety over domestic or business affairs.

Other causes are the intemperate amount of intellectual work which is forced on the brain, and the excessive indulgence of the emotions and the passions. Combined with the strenuousness of life is the large element of uncertainty, the intense anxiety, and the restless energy which is the price of success. Added to these may be lack of suitable and sufficient recreation and short hours of restless sleep; the restrictions of a narrow lot, loneliness, and isolation, the frequent repetitions of uninteresting tasks, added to the burdens of maternity, domestic cares, and worries.

In cities the ear-strain caused by the incessant noises of the street, the amount of work done by insufficient and improper lighting, the unsanitary mode of life, the improper diet, the monotonous and infertile work, the unhappiness and discontent bred of a life of idleness, or one given to society and gambling, whether bridge, whist or poker, the senseless bolstering of shattered nerves with alcoholic stimulants and beverages, patent medicines, and hypnotics, all add their quota to the breaking down of the nervous system.

A man can do a prodigious amount of work if he only varies it with play which really amuses him, or if he substitutes for mental occupation those which involve bodily exercises.

In so-called latent gout insomnia is a frequent symptom, or insomnia may develop as the result of bad nervous habits. Insomnia from whatever cause is followed by the impairment of nerve substance and an overloading of the body with toxins. This continued nerve exhaustion leads to oxaluria, uric acid, gout, anemia, gastric and intestinal dyspepsia, muscular insufficiency, and precordial distress.

Whatever enfeebles the body by overtaxing the nervous system the waste is in excess of the repair, in all overwork the destructive metamorphosis is greater than the reparative processes, and so there is an accumulation of toxic products and a more or less severe and permanent injury is done the nervous system.

Other causes of neurasthenia, not so generally recognized as overwork, are to be found in the pathologic conditions of the intestinal canal, which becomes a veritable culture tube, and absorption from this into the blood constantly takes place. And this condition of putrefaction has to be overcome before relief can be afforded, and in many cases this condition is associated with an insufficiency of the elimination of urine.

The large intestine is the seat of an enormous bacteriologic flora; they are not there by millions, but by billions. Some of them are harmless, but not all of them, and if these pathogenic bacteria are present in sufficient quantity, they, too, may produce symptoms of mild poisoning. So, too, may mere indigestion, or the malfunction of any other organ, torpidity of the liver, a deficiency of the excretion of bile, which is generally accompanied by constipation.

The Symptoms of Neurasthenia.—The symptoms are essentially those of chronic fatigue, which has become exaggerated and pathologic. They may be classified as sensory, motor, psychic, and somatic. The sensory symptoms first noticed are those of generalized fatigue, with such localized sensations as headache, backache, and limbache. The motor symptoms are muscular fatigue, muscular weakness, and muscular exhaustion on slight exertion. The psychic symptoms are manifested by a diminution in the capacity for sustained mental effort and the spontaneity of thought and exhaustion after slight mental effort. The somatic symptoms show themselves in atony of the digestive tract and the circulatory apparatus, with disturbances of the secretions.

Headache is one of the most common symptoms of localized fatigue, and, associated with this, may be a sense of constriction about the head, and there may be either a sense of lightness or fulness of the head.

A woman who is chronically tired loses all her personal vigor, force, aggressiveness, and, above all, will power. Associated with this lack of will power are hesitation, indecision, a marked irritability, and timidity. Neurasthenic patients are subject to spontaneous attacks of fear, causeless in origin, and generalized in character. These attacks may be accompanied by pallor of the face and palpitation of the heart, just as in normal fear. The tired woman is a cross woman. The irritability shows marked impairment of the power of inhibition.

The Rational Treatment of Neurasthenia.—First of all, there must be a removal of the cause which has produced it. There are two distinct classes of cases—the overworked and the idle. The first class, and the most important to the world, are the overworked. We may have to deal with the intellectually overworked, in which the mental overwork was combined with financial anxieties, domestic difficulties, or lack of success in their work, or the cause may have been the tremendous responsibilities of their positions, which involved the lives or fortunes of many people. Added to this great strain and overwork, has been a lack of proper intervals for rest, recreation, and sleep, and the body has become a storehouse for various toxins, and so is suffering from both acute and chronic poisoning.

This class of patients must have the most rigid rest treatment, such as was prescribed by Weir Mitchell years ago. It is most important that the patient should be removed from her old surroundings; if this is not possible, she should be isolated on the top floor of the house with a good nurse. The room selected must be bright and cheerful, with plenty of sunshine and fresh air; a window should be open practically all the time, for oxygen and sunshine are two of the best restoratives. The diet must be easily digested and very nutritious. The patient should be urged not to use her mind at all. Carefully selected short stories may be read aloud by the nurse; the reading should not be continued for more than half an hour at a time.

A great deal may be done to eliminate these toxins from the system by the proper use of electric-light baths, followed by the shampoo and the percussion douche; massage with salt water, salt rubs, and electricity.

In most cases a month of this absolute rest is as long as is beneficial to the patient. And for most of them the sea-shore is the best. There should be enough going on to be diverting without being overtaxing, and a climate should be selected which is warm enough for the patient to live out-of-doors. There should be short walks, drives, sails, etc., and this outdoor life, with a contemplation of nature, is the most powerful restorative. The grandeur of nature, whether it is the mighty forests, with their refreshing shade and quiet, or even stretched in a hammock watching the sky and trees, or the constant surging of the vast sea, bringing rest in its unceasing restlessness, with the ships sailing lazily along, until the whole fades away in the distant horizon. In the vastness of the universe, the ego becomes contemptibly unimportant and insignificant.

After several months spent in this way the body has gotten rid of its toxins, nerves and muscles are rested, and through the soothing influence of nature the neurasthenic is gradually trained back to a healthier habit of thought and a more rational frame of mind. There is substituted for the morbid emotional complex a feeling of pleasure and energy. Reason and judgment reassert their sway; outdoor life quickens the perceptions, and forms tranquilizing memory pictures on the brain that return later to solace and refresh the individual.

There is another, and a very large class, of cases among women of leisure who have suffered all their lives from a lack of a vocation; they have nothing to think of except themselves. They do not know what it is to be quite well; they travel from one part of the country to another, and from one country to another, but they never rise above a certain level of invalidism. They are self centered, and what they need is the work cure. In the majority of cases, before these patients can be restored to health, powerful habits must be eradicated, new interests in others must be supplied to supplant the most intense egotism, new paths must be hewn out in the brain, the will must be recreated, and character can only be imparted by those who possess it.