Reprint from the American Journal of Ophthalmology, July, 1893. THE OS6URREN0E OF MYOPIA AMONG SSHOOL 6HILDREN, TRANSLATED FROM THE GERMAN OF DR. HERMANN COHN’S WORK ON “HYGIENE OF THE EYES.” BY DR. S. C. AYRES AND PROF. J. REMSEN BISHOP, CINCINNATI, OHIO. THE OCCURRENCE OF MYOPIA AMONG SCHOOL CHILDREN. Translated from the German of Dr. Hermann Cohn’s Work on “Hygiene of the Eyes.” BY DR. S. C. AYRES AND PROF. J. REMSEN BISHOP, CINCINNATI. The influence of school life on the eyes is a question which has excited great interest in the medical and educational world since 1865-66, when Dr. H. Cohn, of Breslau, made his first extensive examinations of school children. He examined over 10,000 scholars in different grades, and then later on fol- lowed up the influence of school life, noting the increase of myopia from class to class. His statistics attracted great at- tention throughout Europe and in this country, and soon the good work which he began was taken up by numerous other men. It enlisted the interest of the most prominent men in the profession, and from that time to the present it has contin- ued, until statistics relating to more than 200,000 scholars in various kinds of schools, colleges, seminaries and gymnasiums have been collected. This gives an idea of the immense amount of work done in this line. Statistics such as these are of great value and are worthy of credence. They teach lessons which may guide us in conducting the education of children, so as to avoid the dangers which necessarily surround them. The advantages of this work are shown in the better construc- 2 tion of school houses. Compare the school houses of the present day with one of the old ones constructed say thirty years ago. Here a large percentage of the desks were ar ranged to suit the space in the room, regardless of the way the light would fall upon the desks of the scholars.. In the old school houses the window panes were very small, so that the cross pieces cut off much of the light so greatly needed in our smoky city. Some of these windows still con- tinue to shed their obstructed light on the children’s desks— and this is probably true of other cities. There has also been a marked improvement in the construc- tion of desks. The little tots no longer dangle their feet in mid-air without being able to touch the floor with even the tops of their toes. Desks now are comfortable and built to suit the various grades of physical development. But the most important result of this extensive investigation of the in- fluence of school life on the eyes has been the general spread of intelligence on this point among laymen. At the present time all intelligent teachers in public and private schools, col- leges and seminaries, have more or less information on the in- fluence of school life in developing myopia. in fact the teachers often and, perhaps, generally first . discover these de- fects and report them to the parents. This usually leads to an investigation and a correction of the ocular defect. Children of the present day with optical errors, are able to study with ease and comfort, and more than this their eyes are so protected that they do not suffer from the ocular dis- eases incident to those optical errors. Last year Dr. Cohn published a work entitled “Hygiene of the Eyes.” There is much in it of interest to the medical man, but also much to the layman. Teachers, professors, par- ents, guardians, in fact all who are interested in the education of youth, will find in it a fund of information which is of great interest and value. The book, after a brief description of the anatomy of the eye, discusses the acuteness of vision, errors of refraction, con- stitutional and acquired diseases which affect vision, and then 3 opens up the question of myopia, which is considered in a masterly way from any stand point. Statistics are collected from reliable sources and so treated that the influence of shool life on the eyes of children is clearly shown. The effects of bad illumination—natural and artificial—the influence of ill- constructed desks, of badly arranged rooms, and many other allied questions. The translators have given only that portion of the work which relates to the development of myopia among school children. The exhaustive manner in which the question is handled covers every essential point of inquiry, and the thoroughness of research and the reliability of contributors to the statistics, render them of the greatest value. “Myopia is a very widely spread disease. Among 40,000 patients that came into my clinic, 6,707 were short-sighted, that is 16.8%. Mooren observed among 108,416 patients 8,452, 7.8%, suffering from myopia. A far better insight into the extent of myopia than reports from eye-clinics, is given as by researches among school chil- dren, and we possess in this regard materials which do not ex- ist in such completeness in the case of any other disease. Randall found in the examination of 167 reports that of 213- 690 persons, examined only for the occurrence of myopia, 17.9% were short-sighted. The first communications concerning the eyes of school chil- dren, so far as I can determine, were made by James Ware, in the year 1812. In a military school at Chelsea among 1,300 children, only three complained of short-sight. On the con- trary, of 127 students in Oxford in 1803, there were not less than 32 who made use of lorgnettes or spectacles. “It is poss- ible,” adds Ware, “that several were led to the use of glasses by fashion, but their number is surely inconsiderable in com- parison with those who really saw better through glasses.” Between 1840 and 1850, as Schurmayer relates, inquiries were made in the schools of the grand duchy of Baden, and 4 these revealed that of 2,172 pupils of the 15 learned institu- tions, 392 were short-sighted, that is 1/5th of all pupils. Among 930 pupils in the higher Burgerschulen 46 were found short- sighted, therefore about 1/20. In the fifth and sixth classes (the highest) of the gymnasiums, 25 to 50% of the pupils were short-sighted. In the year 1848 Szokalsky instituted inquiries in Paris and learned that in the College Charlemagne 1 in 9 was short-sight- ed, and in the College Louis le Grand, 1 in 7. This result was the more strange since among the 6,300 pupils in the Parisian elementary schools of the sixth and seventh districts, not a single short-sighted child was found. Szokalsky gives tables illustrating the gradual increase of myopia in the several classes. From the fourth to the first, the scale of short-sight rose in the College Charlemagne as 1: 21, 14, 11, 8, 9; in the College Louis le Grand as 1: 11, 12, 7, 4. In the latter case Szokalsky seems himself to have made the examination, still, this is not absolutely certain. Information concerning the de- gree of myopia is wanting. In contrast with these older observations, which relate to complaints of children, or inquiries or very uncertain proofs, those published by E. von Jager in Vienna in 1861, deserve prominence as pioneer works, for this investigatior was the first to employ personal observation with the ophthalmoscope to determine the refraction of the children. He found in an or- phan asylum among the boys who were 7 to 14 years old,33% with normal sight, 55% short-sighted and 12% hyperopic (far- sighted). On the other hand, in a private school among pupils from 9 to 16 years of age, 18% normal, 80% short-sighted and 2% hyperopic. Jager also noted the varying degree of short sight, although this was not arranged according to classes. His material also (100 cases) was, as he himself says, too small for general conclusions. In the summer of 1865, Riite himself examined from two Leipsig common schools in which 2,514 pupils were enrolled, 213 children sent to him by their teachers as suffering from affections of the eye. Of these 213, 107 suffered from inflam- 5 mation of the lids; conjunctiva and cornea, 107; 48 from short-sight. Therefore the number of short sighted varied be- tween 2% and 3%. Surely a large number of short-sighted pupils did not come within the knowledge of Rute. Since in the case of no one of the older inquiries was the number of children sufficient for the exclusion of accidental causes, nor in any case were the children examined by the physician himself; since, also, the degree of myopia in relation to the classes and the school sites and school seats were not taken into consideration, I undertook, in 1865-6, the examina- tion of 10,060 school children, in such a way that first a pre- liminary examination of all the children was made in the class with letter-tests and then an individual examination with the ophthalmoscope of those who had not seen the letter-tests at the normal distance. Farther, I measured in each of the 166 classes the size of the children and all dimensions of the seats which I chanced to find. I also employed an illuminated chart. In the case of each pupil the age, school-year,reading- test, resulting spectacles and the result of the test with the ophthalmoscope were recorded. In this manner I examined five village schools in Langenbie- lau, Kreiss Reichenbach in Schlewig; 20 town elementary schools; 2 intermediate schools; 2 higher girl’s schools; 2 Realschulen, and 2 gymnasiums in Breslau, altogether 10,060 pupils, of whom 1,486 were village children and 8,574 city chfldren. Of them I found 52% of the village children and 19.2% of the city not emmetropic1 but ametropic2. Altogeth- er 17.1% of all pupils—almost a fifth part—were ametropic. This total would doubtless be considerably larger if I had not at that time excluded all cases of M.1; in in 6.8% S2/s, and in 7.6% S=<2/3. Erismann found that acuity of vision diminished in the higher degrees of my- opia. He observed, however, that the stronger concave glass- es, on account of their diminution of the size of the object, must reduce keenness of vision. Among 1,245 short- sighted pupils, Erismann observed only in 5 % no atro- phic choroidal variations. On the contrary, in 71 % a moder- ate, and in 24% a high degree of choroidal changes. In the higher classes these changes were more frequent. According to the school years they increased from 14% to 58%. In de- grees of myopia more severe than M=3.o, he always found staphyloma posticum; in M.>6.0 even 70 % of serious varia- tions. Erismann observed insufificientia recti interni in 32% of all short-sighted pupils. Serious insufficiency and comparative outward squint was more frequent in the higher schools and older classes than in the lower schools and classes. Already, in the weakest degrees of myopia 23 % of disturbances of muscular equilibrium occurred; the percentage increased with the degree of myopia. In order to put an end to all objections against the demon- strability of the first statistical conclusions obtained concern- ing the increase of myopia among school children, it appear- ed to me a very important duty to examine for refraction the same pupils of an institution after the course of a few seme- sters. Accordingly, in May, 1870, I examined the pupils of the Breslau Frederick gymnasium, and repeated the examination in November, 1871. At the first examination there were found among the 361 children, 174 abnormal, viz: 35% myopic; 7% hyperopic, and 6% with eye diseases. From the seventh grade to the first grade, I found the following increases in the number of the short-sighted: 13,21,27,35,48,58,60%. They showed 12% myopia 0.75 to 1; 47% myopia 1—2.5; 25% my- opia 2.5 to 5, and 6% M>5. After one and one-half years 103 normal-sighted pupils and 71 myopic had left the school, only 84 formerly observed as normal and and 54 ob- 12 served as short sighted—altogether 138—could again be exam- ined. Of the 84 formerly observed as normal only 70 had remained normal; that is, 14 or 16% had become short-sight- ed. The degree of myopia existing meanwhile varied from O.75 to 2D. Of the 54 previously short-sighted, 28 had suffer- ed a decided increase in degree in the one and one-half years. I found in no case a decrease. Both the lowest and the highest degree of short-sight, added their contribution to progressive myopia, as follows: Myopia. Increased in—Per Cent. O.75- 1 30 I — 1.25 - 33 I.25— 2-5 - 69 2-5 — 3-25 - IOO 3-25- 5 43 > 5— 10 66 Among 54 examinations, in 28 i■ e. 52%, myopia was pro- gressive. The average of the short-sight of all 28 progressively short- sight pupils was, the one and one-half years previously, M=2, now M.=2.75; in this short time the average therefore in- creased M.=o.75. Concerning the acuity of vision it is important to note that all pupils formerly found normal and now found short-sighted had preserved complete sharpness of vision. Only in two cases of stationary myopia (among 26) had the sharpness of vision sank from 2/3 to 2/5. Among the 28 progressively short- sighted pupils, one and one-half years before S=i; in the case of four it had now decreased 2/3 and 4/5. Five of the pro- gressively near-sighted had before sharpness of vision 2/3. In no case had decrease of sharpness of vision supervened. I found staphyloma in the case of 14 who had, from normal sight, become short-sighted; 26 stationary short-sighted pupils had formerly 7 now 14 staphyloma. In 12 cases of stationary myopia no staphyloma occurred. Among the 28 progressively 13 short-sighted formerly 15 now 22 had staphylomata. There had occurred, therefore, within three semesters, 10% of chan- ges in the posterior portion of the eye. These results were confirmed by von Reuss, who repeated his investigations in the Leopoldstadt Gymnasium in Vienna, in the years 1874, 1875 and 1876. He had examined with the mirror all short-sighted pupils, and all whose S was <1; also he had tested each normal-sighted pupil by means of convex glasses for possible far-sight, and had examined each eye sep- arately. In May, 1872, he found among 409 pupils, 35% nor- mal, 41.8% myopic and 20.5% hyperopic; 2% astigmatic and 7% with eye-diseases. The number of the short-sighted in- creased from class to class: 28, 41,49,48%. Far-sight de- creased from class to class: 30, 27, 14, 12%. He found the low degree H 3. By comparison of results obtained through sight-tests and the mirror, von Reuss found, i. Apparently, progression is brought about by spasm of the ciliary in a not very large number of eyes. Spasm of the ciliary can exist several years without affecting the structure of the eye. Spasm of the ciliary changes the real refractive condition in the direction of progression; this is the most frequent result. 3. Progressive changes come without accompa- nying disease of accommodation; this result is by no means rare. Therefore, the origin of myopia or its increase, does not always depend upon spasm of the ciliary muscle. On the contrary, Burchardt, in Berlin, was led by determinations of the near-point to the conclusion that disease of accommoda- tion has always been present a long time, and is, almost with- out exception, the cause of definite short-sight. Worthy of recognition as the careful mirror-examination by most late investigators of the refractive condition of all pu- pils is, it is still by no means infallible. I have often enough observed that accommodation is not relieved of strain with plane mirror and in large rooms—indeed, that it is in some cases strained even there; this is also admitted by von Reuss and Stellwag. Further, not a few cases are known to me in which experinced colleagues, who are very proud of their determinations of refraction with the erect image, have erred by 1—2 D, especially in the case of weak myopic and hyperopic subjects. The total measure of the accommo- dation muscle is, indeed, not always quite certain. Therefore, statistics founded upon observations of this kind, are not ab- 15 solutely certain; to this end all children and, if possible, the observer himself must be atropinized. Homotropine in weak so- lutions acts upon the accommodation too ineffectually to make us lay any real weight upon measurements by this means. Durr, in 1883, examined with homatropine, the pupils of a ly- ceum, but only 318 of 538 underwent the administration of the mydriatic. Naturally, Durr found diseases of accommodation frequent in all conditions of refraction. For questions of hy- gienic statistics reading-tests and spectacle-tests will, in the case of school children retain their great value. Also, Conrad very carefully examined the school children in a body with the ophthalmoscope and with spectacles, and is of the opinion that with the mirror one is never sure that ac- commodation is fully relaxed. He, however, considers that differences when atropinization was used are “extremely small.” He found among 3.036 eyes, by reading tests: hyperopia 11 %; emmetropia 55 %; myopia 32%; by mirror, hyperopia 47%; emmetropia 29%; myopia 22%. For the rest he agrees with Erismann, that hyperopia slowly passes through normal sight into short-sight. With the mirror he found in the lowest classes 70 % hyperopia; in the highest only 22%, emmetropia in the lowest classes 25%, in the highest and in the middle classes 30 to 35%; also, myopia rose from 4 to 51 % by mirror-test, from 11 to 62% by the reading test, so that there was about 10% of spasm of accommoda- tion present. Repeated tests of the same pupils are found in the late work of Ott, in Lucerne; of Netoliczka, in Graz; of Flor- schutz, in Coburg; of Erismann, in St. Petersburg; of Reich, in Tiflis; of Derby, in New York; of Albrecht, in Strassburg; of Adamiik, in Kasan, 1877 to 1886; of Haab, in Zurich, 1882 to 1888; in the Russian cadet-corps, 1882 to 1887; of von Hippel, in Giessen, 1881 to 1889, and of Schmidt Rimpler, 1885 to 1889. The communications of Florschutz show results of the high- est interest, since they show the decrease of the nuqiber of short-sighted pupils in the newly constructed “school palaces.’ 16 Thus, the common schools showed still in 1874 12 and 14, in the year 1877 only 4 and 7% myopic; 2323 pupils examined in 1874 showed 21 %; in 1877 only 15% myopic. Erismann found in 1876, in the case of 350 eyes which he had examined in 1870, 67% increase of short-sight, of which 16% was change from emmetropia to myopia, and 25 % increase of myopia. Reich saw in six years 14% change from hyperopia to myopia; 44% from emmetropia to myopia, and 81% increase in my- opia. H. Derby examined 254 students of Amherst College (19 to 23 years of age) again four years after entrance into the insti- stution, and found instead of 15% hyperopic, 49% emmetro- pic and 35% myopic, which had been recorded on entrance; 18% hyperopic. 34% emmetropic and 47% myopic. Of the 125 normal-sighted 23% had become myopic; the degree was on the average iD. This fact is of the greatest importance, because widespread opinion since the time of Donders, holds that after the age of 15 myopia does not often develop in eyes hitherto sound, and that after the age of 20, it never develops in sound eyes. From my own practice I can produce many observations similar to those of Derby. Derby shows that of 90 short-sighted students, 32 kept their degree of myopia; 28 suffered an increase of 1—2.5 D during their four years course. The average degree at entrance was 1.8 D; at graduation 2.4 D; an average increase, therefore, of 0.6 D. Ulrich had charge of 273 eyes which Hoffmann had exam- ined three years before. He showed in 44% increase in re- fraction, Mi to Adamiik maintained in 1886 that pre- vious observers had not made repeated examinations of the eyes of the same pupils. Prom the foregoing it is seen that he was not acquainted with the literature of the subject. He himself examined two gymnasiums yearly for nine years. At first, of 317 pupils 14% were myopic, who in 91% showed in- crease of short-sight; also 52% hyperopic and 32% emmetro- pic suffered a change in their refraction. 17 Haab in Zurich continued yearly till 1888 the examinations begun by Horner in 1882. Of the 309 pupils then examined, 208 were still in the school after 6 years; at first 16% were ametropic and 3% myopic; after 6 years 25 % were ametropic and 11% myopic. The short-sighted had increased fourfold. The examinations conducted from 1882 to 1887 in the Rus- sian cadet corps, on an average 1896 pupils yearly showed in these 6 years: 24, 24,24, 30, 23, 23% myopia, an average of 25%. In these observations, however, the lowest degrees were considered, 32% 3.25 and <5 27.5 35-5 32.O and <^6 9.0 10.0 IOO M>6 0.0 4-5 3-5 Emmert made tests in four Swiss Watchmakers’ schools and observed 71 per cent, hypermetropic; 15 per cent, emmetropic and 14 per cent, myopic. Especially frequent there was in- sufficiency of the internal recti, 54 per cent.; also in the schools of those places in which watchmaking was pursued, 22 per cent, of insufficiency was found, as against 4 per cent, in other towns. Emmert believes that watchmaking, on account of the use of one eye with the magnifying glass, very easily gives occasion for disturbances of the muscles, and that the tenden- cy to this is very easily inherited. 21 According to Maklakoff, the percentage of myopia among the Georgians and Armenians in the Caucasus, must be very small. Reich asserts the exact opposite, who also consid- ers as very questionable the opinion of Dor: “The farther south you go the more normal eyes you find,” and he suggests that Mannhardt especially comments on the national tencency of the Italians towards myopia. In four tows of Tiflis, exam- amined by him, Reich found among the Georgians and Armen- ians more short-sighted than among the Russians. For exam- ple, in the gymnasium, 38 per cent, of Armenians; 43 per cent, of Georgians, and 30 per cent, of Russians; also, he ob- served among the former a higher degree of myopia and a more rapid increase of per centage of myopia with the classes. He was struck with the large, almost prominent eyes of the Armenians and Georgians. The Armenians, also, had more myopia among them than the Grutinians. In the lowest class- es of the gymnasium in Tiflis, Reich found only 12; in the highest, 71 per cent, myopic. Moreover, S=9/6 in 52 per cent, of the pupils. The wide occurrence of myopia in Russian educational institutions has been shown by Erismann and other observers. The Ural gymnasium, exam- ined by Dobrowolsky, forms an exception. This contains mostly Cosack children, and showed only 12 per cent myopic. Net 77 per cent, myopic are reported in the gymnasium of Irkutsk. Up to this time only a few researches have been made in England. Priestly Smith found in 1880, among 1,636 school children, 5 per cent, short-sighted, and among 537 seminary students, 20 per cent, myopic. In 1883 Hadlow found, in the schools at Greenwich Hospital, which are reserved for preparation for naval service, among 1,074 pupils who, at their entrance into the institution at the age of 13, had possessed normal sight, after two and one-half years, at the end of their course, 60 pupils affected with myopia, complicated with such disturb- ances of vision that they had to be rejected as unserviceable in naval employment. Therefore, in two and one-half years 22 5!/2 per cent, had become so short-sighted that their special preparation for naval service had become useless. Ellis ob- served in 1885, in the primary schools at Oxford and Hamil- ton, 24 i. e., 11 per cent, myopic. Frost, in London, observed 11 per cent, short-sighted. In France, in 1874, investigations were instituted by Gay at in Lyons, and included children picked out “on hand or seen au demande du Maitre, in this fashion: a pres de 600” were examined. The number of short-sighted pupils being thus de- termined, it is not fair to accept this 3 per cent, myopic as rep- resenting the per centage of the total number of pupils. Dor, at first, referring to Gayat’s statistics, concluded that there was far less myopia in France than in Germany. Later, he himself in Lyons, in a lyceum, examined the pupils, and found them 23.4 per cent, myopic (the same as in German gymna- siums. Nicati in Marseilles, examined 3,434 pupils with glasses and the mirror, and found in the Jewish primary schools, 15 and 10 per cent, myopic, as against 8 and 7 per cent, in the Christian primary schools. Nicati offers this as the best evi- dence for inheritance, since the Jewish pupils are children and descendants of store-keepers, and the Christian children are descendants of hand-workers, craftsmen and peasants, and in their families from the first generation enjoying school-train- ing. Weiss, in his investigations in Mannheim, was unable to find this excess of myopia among the Jews. Myopia was very frequent among Jews and Christians; still, Weiss found in the gymnasium of that city less myopia (30 per cent.) than in Hei- delberg (35 per cent.); he thinks the inheritance of myopia less in the trade and manufacturing towns of Mannheim than in Heidelburg, inherited by the rich class of learned and office-holding people. Also, Kuchner in 1889, was unable to find any important differences between Jewish and Christian pupils in the Berlin gymnasiums. Of 367 Jews, 36 per cent.; of 1,023 Teutons, 35 per cent, were myopic; but Kirchner ob- served more frequent among young Jews than among Teutons. M)>4D more frequent among Jews than among 23 those who were not Jews. He thinks that the reason for this must be sought in the earlier bodily and spiritual development of the Orientals. In Italy, at the instance of Simi, in 1884, by Del Carlo, in Lucca, by Scellingo, in Rome, by Masini in Siena, by Magne, in Naples, by Brignoni, in Trapani, and by Saltini, in Parma, investigations were undertaken which show a very close cor- respondence in results with those obtained in German institu- tions. Also results obtained in Sweden and Hungary resemble those obtained in Germany. In Roumania, Manolescu observed in Roumania elementary schools, among lower and higher gymnasium pupils, 2, 4 and 16 per cent, myopia; on the contrary, among pupils not Rou- manians he found 15, 11 and 21 per cent, short-sighted. In America, Callan examined 457 negro children. They were from 5 to 19 years of age, and attended two New York schools. Only 2,6 per cent, were myopic; in the higher school 3.4 per cent.; in the lower 1.2 per cent. The short-sighted were, as a rule, over ten years old. The higher degrees M5 to 10 occurred among pupils over 14 years of age. In the pri- mary departments of both schools there were no short-sighted children; in the higher classes of the primary departments,8. 2 per cent, and in the lower schools, 1.6 per cent. With glass tests Callan found only 67 per cent, of hypermetropia. After he had atropinized himself (truly as valuable for the examina- tion as uncomfortable for the examiners) he found, by the mirror, 90 per cent, hypermetropia. In the Indian schools at Carlisle, Fox observes only 2 per cent, of myopic pupils. In like manner Loring and Derby made researches in New York among 2,265 eyes of school children, and found the same in- crease of myopia as has been found in .Germany, according to classes. It is interesting to note that among children of Ger- man parents they observed 24 per cent.; among children of American parents only 20 per cent., and among Irish children, only 15 per cent, myopia. On the whole the number of short- sighted children was less than in Germany; in the primary 24 schools 7; in the district schools 12, and in the normal schools 27 per cent, myopic. An examination with glasses and mirror which Agnew had made, through a number of physicians, of 1,479 Pupds in different higher and lower schools in New York, Cincinnati and Brooklyn, showed in Cincinnati in the common schools 10; in the intermediate schools 14, and in the normal 16 per cent. The result in New York was: In the lowest class, 29 per cent.; in the freshman class 40; in the sophomore class 35; in the junior 53, and in the senior 37 per cent, of myo- pia. In Brooklyn there were found: In the academic depart- ment, 10 per cent., and in the collegiate department 28 per cent, myopia. Haskert Derby found in Amherst college, 28 per cent.; in Harvard college 29 per cent, myopic. After a year, half of the short-sighted had reached a higher degree of myopia. After 4 years he repeated the examination and found that 10 per cent, of emmetropia had changed into myopia, and that myopia had increased 21 per cent. In 1875 he found: Emme- tropia, 51 per cent.; hypermetropia, 5 per cent.; myopia, 45 per cent. In 1879 he observed: Emmetropia, 36 percent.; hy- permetropia, 13 per cent., and myopia 51 per cent. It is thus seen that American pupils approach very near to the German in myopia; at any rate Randall found in Philadel- phia, among 92 medical students, conspicuously, only 10 per cent., while Risley, in the normal school of Philadelphia, over 19 per cent, myopia. In Buenos Ayres, among 6,163 children, only 4 per cent, were found myopic by Roberts. Collard, among 790 eyes of Dutch students, observed only 27 per cent, myopia; but among 30 eyes of German students at Utrecht, he found 40 per cent, myopic. From Oriental schools we have few reports. In a Greek school in Smyrna, Issegonis found 46 per cent, myopic in higher classes. Upon a visit to Constantinople in 1877,1 had access to three Turkish schools, a high school, a military school and a people’s school, in which no teacher or pupil wore glasses. In the 25 military school,General von der Goltz-Pasha examined 379 pu- pils with my table, and found 17 per cent, ametropic, exactly as great a proportion as was found, on the average, among the 10,060 school children of Breslau, in 1865. Among 67 Jem- enlis (South Arabians) and Tripolitans, who are recognized as short-sighted, there were 40 per cent, ametropic. We do not know how many of them were short-sighted, since no tests with glasses were made. From all the figures given above it only follows with cer- tainty that in the whole civilized world, in all nations, the num- ber of the short-sighted increases with the demands which their school work makes, aridfrom class to class. The Myopia of School Children not an Unimportantt Disease. The continued confirmation of the wide occurrence of myo- pia among school children and the increase of short-sight from class to class have, since, 1865, engaged the attention of all physicians, teachers and officers, and a series of hygienic sug- gestions for the prevention of school-myopia has been called forth. For several years, however, the voices of well-known physicians have been loud in proclaiming that too much is be- ing made of myopia; that it is not a disease at all. The first who, in a mild fashion, took opposing ground was Donders himself, whose opinions set forth in 1881, very con- siderably retreat from his outspoken position in 1864. The same Donders had said: “I say without hesitation that a short- sighted eye is a diseased eye,” and we had considered each case of progressive myopia as a case of actual disease. The same Donders, who remarks on the preface to the German edition of his works (1866): “For a series of years I have made incisive examinations of the anomalies of refraction and accommodation of the eye, and have determined and tested all the circumstances relative thereto in the case of thousands of eyes;” the same Donders who says at the close of this preface: “Practice joined with learning has here reached the 26 unusual and glorious consummation of being able to give some prescriptions grounded on ascertained principles, and of being led by a clear insight into the nature of its treatment;” the same Donders declared in 1881, that the injurious consequen- ces of myopia had been much exaggerated. “If the highest degrees are worthy of attention, still they are usually to be cor- rected by timely use of suitable glasses, and the lesser de- grees bring with them a capacity for fine hand-work and learn- ed investigations, which we could not willingly miss. “In truth,” says Donders,” with the same emphasis witu which he asserted the contrary seventeen years earlier, “if it lay in my power to exclude all short-sight from the world, I should not want to do so. In myopia we see an example of this in certain directions desirable adaptation of an organ to the influence of its use. In use lies immediately a correction for far-sight, which occasions only discomfort and not pleasure. The question is whether in contending with myopia we cannot over-shoot the mark. It would not be at all unsuspected by me, if in the end, the learned and the peasent class have each the most efficient eye for its purposes.” Hitherto no testimony has been adduced that increase ot myopia can be stopped by timely provided glasses. I can pro- duce from my case-books many cases to the contrary, in which near work, in spite of glasses early provided, occasioned in- crease of myopia. Furthermore, the advantage which several thousands of men who persue “learned occupations, and (to my mind very super- fluous) fine trades,” derive therefrom, that they need no con- vex glasses in old age for close work, entirely disappears when weighed against the suffering which millions of short-sighted men suffer if they have not their distance-glasses, and when weighed against the dangers of progressive short-sight. Don- ders here forgets that in the case of increasing myopia sharp- ness of vision is lost and that, therefore, no distance glass re- stores for distant vision normal sight to the highest degrees of myopia. The man possessing normalsight who wishes to persue “learned occupations and fine trades,” can see these 27 fine manufactures with ease by means of convex glasses, and sitll preserve his good vision for distance. For the sake of the comfort of a few thousands of workers in delicate manufactur- es, and of natural philosophers, to wish that short-sight may not be excluded from the world, is a thought not to be serious- ly considered. Also, the view of Donders that myopia is a wholesome cor- rection for hypermetropia, zvhich occasions only pain and no pleasure, is only a sounding phrase. It is not a question of pain, but of danger. Hypermetropia brings no danger, myopia occasions it often. The far-sighted man becomes normal through a convex glass, and his eye in the interior suffers no injury; the short-sighted man, in spite of a glass, suffers inter- nal changes of the eye. It is necessary, therefore, to test these remarks of the changing Donders on the subject as of slight value. On the other side, Donders set forth anew in 1881, that “myopia of a high degree is not only an inconvenience but also a danger to the eye,” and that, if it is true that myopia is spreading, we have every reason to check it. In Holland my- opia is of less frequent occurrence than elsewhere and, of higher degree is seldom encountered there. For this reason few statistical examinations have been made there. Little good is to be expected from further tests of school children. It is of more importance to examine young people of different classes during the period in which the degree of myopia becomes stationary for life; that is to say, students on the one hand,and on the other young people from the peasarvt class. If, after a period of years, such examination was repeated, it would be possible to decide whether myopia is spreading. Also Otto Becker, in 1883, held that the view that myopia is increasing now as compared with the past, has not been estab- lished. Twenty years ago myopia was not distinguished from hypermetropia. It will be necessary, particularly to gather perfectly accurate results among those bound to military serv- ice, and repeat them for 25 years, in order to find out whether an increase is taking place. 28 Donder’s wish was answered by Tscherning in Copenhagen; in the year 1883 his work appeared, which treats of observa- tions upon 7,564 persons from 18 to 25 years of age (not only school children, but also men in military service of all ranks). He examined only with the eye-mirror, and did not in the first year take into consideration his own M of 0.5D. Besides, he in- troduced an entirely arbitrary classification,in which he reckon- ed every M<(2D and every H<(2D as emmetropic, which is entirely false. He who needs correction for—or -)-1.5 is just as abnormal as he who needs—or -|-2D. Although, therefore, he reckoned many as normal-sighted who were not so,yet he comes to the conclusion that the influ- ence of close work is plain. Among students he found 32 per cent.; among clerks, 16 per cent., among hand-workers, who do only average work, only 5 per cent., and among country folks, only 2 per cent, myopic. He holds close work to be a cause of myopia, but considers this, when it re- mains within narrow bounds (3D), as unimportant. The higher degrees were rare in the schools. The last conclusion is noth- ing new. I, also, 26 years ago, found among 10,000 children, 919 with Mi—3; 76 with M3.5, and only 9 with M5—6, but not a single case of myopia greater' than 6. When Tscherning now finds the highest degrees M9—12 more frequent among country people, and considers that these higher degrees are congenital and follow altogether different laws; this also is nothing new. Already in the beginning of this century cases of severely myopic country people were discovered; but this does not at all invalidate the laws concern- ing the increase in the number and severity of cases of myo- pia in schools. Tscherning observed the people only at the age of 20 to 22; what the condition will be in their fortieth year he naturally cannot know. When he states that the dan- gerous diseases accompanying myopia concern only he errs. I have observed detachment or defects of the retina in the case of M5 or 6, and every oculist knows that disturb- ance of vitreous humor, injurious muscle insufficiency, and inflammation of choroid occur frequently in the lower degrees. 29 M6 is in itself a very uncomfortable condition for life. More- over, I found among 7,523 persons whom Tscherning examin- ed, only 2.9 per cent. Mj>6, in whose case close work was the occupation, and only 1.6 percent. who did no close work. Therefore, then, it has been shown why we should decide that though admixture ot school-myopia with pernicious myopia the former has been really over-estimated. Tscherning conceives school-myopia as an anomaly caused by work, produced through adaptation of the eye to work\ not, however, as a real disease. Where has he given proof that out of the so-called weak work-myopia the higher degrees do not afterwards develop? When Tscherning considers myopia up to 9D as unimportant for the future, because among his pa- tients he has seen no case of complete or partial blindness, we can only wish for him, as Donders did for E. von Jaeger, in 1866, a long life and a wider sphere "of work, that he may be able to examine his 20 years old myopic subjects in the fortieth and fiftieth year of their life. Just then, as Horner has shown the bad forms of short-sight, in the case of previously light degrees, develop themselves. The setting of the limit at 9D is entirely arbitrary with Tscherning. M6 is considered by the military authorities as the least for admittance. Vessely, in Vienna, in like manner as Tscherning, found among 1,405 military servants at the age of 20 to 24 years, that 35 per cent, had 39 per cent, had M3—6, and 26 per cent, had M7. The educated divided themselves into three groupes, 21 per cent., 24 per cent., and 10 per cent.; the uneducated into 13 per cent., 15 per cent., and 17 per cent. Therefore, myopia was far more wide-spread among the edu- cated, but only in moderate degree; the high grades were more numerous among the uneducated. Also,Stilling considers myopia of moderate degree as unim- portant; but he is too keen a student of Darwin to dispose of this myopia in Tscherning’s manner. Indeed, he holds the view that myopia as a phenomenon of adaptation, is a mis- understanding of Darwin’s teaching. Too short a time since the diffusion of close-work has elapsed for an adaptation in 30 Darwin’s sense. He thinks it must be compared with anala- gous incidents, such as the so-called “ride-leg,” or the “hands of the piano-player.” One may dispute with Stilling whether the moderate degrees of short-sight are an evil, or, if they are, whether “this work-myopia, compared with the great num- ber of greater ills, is small and very tolerable, and not at all of a nature to rouse serious fears? Truly, we an- swer, cancer, diphtheria and cholera are far more dangerous than myopia; but, is loss of distance sight a matter of indiffer- ence because there are worse ills? Every normal-sighted per- son who, for one day should wear constantly glasses -|-3D,and thus artificially make himself so short-sighted that he could see clearly only one-third of a metre, would be of a very dif- ferent opinion. I will not comment upon the bad state of the short-sighted soldier, rider, hunter, sailor, etc., whose glasses have been lost, broken, bent or only tarnished. Concerning the diseases of sharpness of vision, even in the case of slight- ly myopic persons, something more searching will be said be- low. Also, von Hippel attached himself to Tscherning. When he found in a gymnasium of good hygeinic condition in Gies- sen, 34 per cent, of myopia, he wrote the monstrous sentence: “Education and knowledge are not by any care now to be ac- quired without a certain injury to the body.” In 1889,in spite of my rebuke of this sentence,he held it to be “fully and entirely correct,” and added that, in spite of the knowledge that read- ing and writing among youths has a disadvantageous effect upon their eyes, we are compelled to keep them at their stud- ies. I argued to the contrary: 1. If, in truth, education and knowledge are not to be ac- quired without a certain injury to the body,then must#//school children, who collectively are busied with reading and writing, become short-sighted, while myopia attacks only, on an aver- age, 20 per cent, of all pupils. If von Hippel’s assertions were correct, we ought also to be able to apply it to other bodily functions of the children. How is it in this regard with the influence of education and knowl- 31 edge in music? Has anyone yet heard that the hearing of a child had suffered through musical practice? Surely it would suffer if we sounded loud notes for many hours close by the ears. Or shall we, perhaps, find that, if a child is occupied with the acquisition of education and knowledge, the brain suffers injury? Of course, this would suffer if it should be over-worked from morning till night. In its generality the assertion of von Hippel is, therefore, untenable. 2. I contend also that reading and writing in themselves, do not produce myopia. Only reading and writing in poor light and in improper positions, and the excessive, hour-long, one- after-another recurring reading and writing produce and favor myopia. Proof: the average very infrequent occurrence of myopia in elementary schools (in five village schools I found i per cent.; in twenty public schools 7 per cent, of myopia on the average) who yet write and read as much as the pupils of the gymnasiums. Farther, the increase of myopia in dark public schools (8 to 15 per cent., as against 2 and 7 per cent in light localities). Also, Kirchner, in his otherwise excellent late work, holds that the acquiring of myopia by a number of children “is a sac- rifice which we must make to education, and of necessity must make it, just as we are both compelled and willing to give our life, if required, for the honor and success of our father-land.” How can school and army be compared? We do not send the children to school for the defense of our fatherland, but for their education, in which they ought to remain just as healthy as when they went to school. Farther, von Hippel took up the assertion already made by Javal, “that perhaps a larger per cent, of short-sighted pupils are found in the higher classes because more normal-sighted children may have left school in the middle classes.” Any reasonable general cause why only the normal-sighted should depart and the myopic study farther is, of course hard to find. Von Hippel reckoned that, while up to the lower third class the proportion of those going and those remaining was ap- proximately the same; in the higher third class 6 per cent, of 32 short-sighted pupils departed as against 24 per cent, of myop- ic pupils, on the average. I went over the calculations and found that only 4 pupils, on the average, left the higher third class. On such figures, no one could seriously build any conclusions. Moreover, Schmidt-Rimpler recently brought positive proof that perceptibly more short-sighted leave the higher classes than the lower. Among 809 who had left short-sighted were found: from sixth, 12 per cent.; fifth, 16 per cent.; fourth, 17 per cent.; lower third, 33 per cent., higher third, 38 per cent.; lower second, 43 per cent., and higher second, 45 per cent. Besides, it is a gross error to believe that all who leave take up another life calling. In Frankfurt am Main, of 186 who left the gymnasium, 145 went to other schools. It is to be seen from the above how wrong is the view of those who consider short-sight an unimportant disease. Of course, the introduction of the Darwinian theory that my- opia is for people an adaptation to surroundings, to close work and not a disease—one which the great Darwin would not have understood and a very false use of the theory—and the efforts of Stilling, Tschering and von Hippel, to prove myopia an unimportant, harmless anomaly, were very agreeable to the pedagogues, especially to Wingerath and the authorities who are unfriendly to modern hygienic regulations. The view of other well-known investigators stand diamet- rically opposed to those of Tscherning, Stilling and von Hip- per. At their head stands Horner, who was himself short-sighted. This makes his testimony of greater weight. Some speak of myopia as an appropriate adaptation to the act of work, like the skin of the finger of a violin player, which grows thick. If we wish to continue the idea of adaptation to an end sought with the idea of adjustment to circumstances, this conception of myopia is entirely untrue. In growing years the majority of eyes have no necessity of becoming short-sighted since power of accommodation if fully sufficient for work; and af- ter youth is past short-sight offers more danger than advant- 33 age. If we wish, considering adjustment alone, to say: “The change is the necessary product of use, of its extent and of its kind, then this is correct. Then let no one forget that ad- justment very frequently passes the bounds of health, whether we consider the flat foot of the mountaineer, the emphysema of the trumpeter, the arched back of the professional gym- nast, or the short-sight of the student; it is when undue requisition upon the function of the organ is made, and when the function does not observe the right mean between rest and work.” In direct contradiction of the views of Stilling, Horner con- siders myopia a great hindrance to choice of occupation, and to advancement in life. In many callings of life, especially in the case of the female sex, the wearing of spectacles is impos- sible, as such powerful glasses are required that they will not wear them at all. “He who has experienced the chagrin of not being able to persue a cherished calling, of not being able to choose the business calling on account of short-sight, has a right to emphasize this economical side of the matter.” Horner’s experiences with the danger of short sight are very correct, and are deserving of the widest dissemination. “The degree of myopia which indicates the bound beyond which danger is almost the rule, is shown by M6 (not 9, as Tscherning believes). Since this degree of myopia is easily reached by those who at twelve years of age have only one-half, a higher grade of myqpia is the more dangerous the younger the person is who develops it. Also now a fact cannot be given too great prom- inence. “ The danger of loss of the very short-sighted eye in- creases zvith age, and becomes, on the average, from the age of go or over, more threatening. Of 1,878 short-sighted people whom Horner examined in his practice from 1880 to 1883, 34 per cent, developed dangerous complications; 9 per cent, diseases of vitreous humor; 11 per cent, inflammations of the choroid; 4 per cent, detachment of the retina, and 23 per cent, catar- act. The average age of these 629 cases of complicated my- opia was 50.3 years. As is known, special schools have been proposed for the 34 short-sighted; Horner considers them unnecessary. We rath- er agree entirely with his words: “It would be better to treat all children as if they might become short-sighted.” Horner comes to the commendable conclusion that the war against myopia and its spread is one warranted by the need of those who are becoming short-sighted, for those who are so, and for those who come after. “Fortunately the battle has broken out all along the line; we should take advantage of it before it flags”. Also Schmidt-Rimpler comes to similar conclusions and holds that the view that the danger from myopia begins with M 9, does not agree with clinical experience. He correctly emphasizes the fact that in spite of correcting glasses, myopia of middle and higher degrees causes loss of keenness of vision for distance.—The following determinations of keenness of vision in the case of 3420 eyes of school- children prove this: %S>i = %s>v2= %s6 16 65 19 H<3 - - 45 31 24 H>3 - - 12 38 50 Astigmatism- 1 52 47 Scherdin found in the Real-Schule in Stockholm, as Key reports, normal keenness of vision in the case of only 70% of short-sighted pupils. Leininberg in Wurzburg examined 2893 myopic eyes for keenness of vision. This was found to be with M<2D; S~o.g with M 2—4; S=0.8 with M 4—6; S=o,6 with M 6—10; S=o.5 with M 10—12; S=o.3 with M 12—18; S=o.2 with M>i8. Priestley-Smith argues against the view that short-sight is a development of the human eye. He says, “If myopia is an accompaniment of intellectual progress, it is an accompany- 35 ing evil. If nature had in fact the development of the eye in view, then she ought to change the action of the accommoda- tion muscle and make possible an active accommodation for distance, that the short-sighted person might acquire the abili- ty to see in the distance. Also Schiess-Gemuseus and Seggel argue warmly against Tscherning’s view that myopia induced by reading is to be considered unimportant. Seggel proves the really injurious influence of myopia by the following tables of 1619 myopic eyes examined by him, of which he determined the keenness of vision. « Eyes Myopia Average Keenness of Vision i 86 O.25 I.I 74 - O.50—O.75 O.92 267 - 1.00—1.75 0.80 239 - 2.00—2.75 O.77 186 3.OO—3.75 - O.75 200 - 4.OO—4.75 O.73 173 5-00—5.75 O.65 103 - 0.00—6.75 O.59 85 - - - 7.00—8.00 - O.55 68 - 8.00—10.00 O.53 26 10.00—13.00 O.4O 12 - 14.00—20.00 O.13 Seggel very correctly adds in conclusion: “Since myopia even in its lozvest degree of 0.5 D is accompanied by Sfi and since keenness of vision decreases in proportio7i to increase of myopia, therefore the combating of myopia, not only on its own account but also on account of the necessarily accompanying decrease of keenness of vision, is a pressing duty not often enotigh urged." Nagel expresses himself not less energetically. He is a learned investigator and a keen critic. Stilling had proclaimed that myopia caused by work “is not to be taken so tragically”, as chanced to be done by several oculists. He says that 36 higher myopia offers advantages and moderate degrees are harmless, that serviceability of the many is not injured by the increase of myopia, that it is time an end was put to the disturbance made at the expense of the school authorities, that the oculists should have a care not to thrust themselves into the domain of instruction and matters of this kind. Nagel considers all these objections unfounded. “The injury of continued close-work,” says he, in spite of all Stilling says with exaggeration of the harmlessness of myopia, remains proved for every unprejudiced observer, and, apart from the connection of cause and the associated theories it is warranted and imperative to combat most earnestly the injury wrought by too early and too severe close work. What has in this matter been gained with much exertion, we should not lightly ridicule and reject.” In similar manner Pfliiger attacked the underrating by Stilling of the harmfulness of close-work, and asserted that his unfounded conclusions since they imperilled the progress already made in school-hygiene, must work harm among the laity, especially in the educational world. We declare ourselves of this opinion after twenty-five years of investigation and we affirm that, in spite of the objections of the above works setting forth the importance of myopia, we are unable to find one author who is not of the opinion that in the Schools everything should so be arranged that it ivill not cause injury to the eyes.