The refraction of the human eye : a critical study of the statistics obtained by examinations of the refraction, especially among school children / by B. Alex. Randall.

  • Randall, Burton Alexander, 1858-1932.
Date:
[1885]
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Licence: Public Domain Mark

Credit: The refraction of the human eye : a critical study of the statistics obtained by examinations of the refraction, especially among school children / by B. Alex. Randall. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    gation it is hardly more tlian incidental. We will group these institutions, then, by the side of the so-called higher schools, which aim at liberal education; only premising that we are dealing now with pupils between the fourth and the twelfth school year, or between about the ninth and the eighteenth years of life. Combining the foregoing figures, we find as the result of examinations as to myopia in 50 gymnasiums and lyceums, 14 realschule, 7 seminaries, and about 50 other schools :— In 55,342 examinations (individuals or eyes) 14,907 = 26.94 p. c. myopic. Studying, now, those in which all conditions of refraction were sought, we obtain:— In 42,763 exam. Em. 15,996 = 37.40 p. c.,M. 11,757= 27.49 p. c.,H. 13,145 = 30.74 p. c, the H. probably here, as before, fairly'representing the manifest hyper- metropia, and the other figures the apparent myopia and apparent emme- tropia, respectively. In the studies where the H. t. was sought, we find:— In 9965 examinations Em. 2159 = 21.66 p. c, M. 2149 = 21.56 p. c, H. 5587 = 56. p.c, Here Just's results are again excluded, as well as those of Weber, of Becker, and of Beselin, where the figures given are confessedly incomplete and not available for our purpose ; while Erismann's 1825 = 43 per cent. H. m., Pfliiger's 404 = 40 per cent. H, m., Emmert's 2712 =76.1 per cent. H. m., and Kotelmann's 273 = 48.8 per cent. H. m. are, of course, omitted. Studies of the relations of normal vision, apparent Em. and Em., of appa- rent M. and M., and of H. absolute, H. manifest and H. total, give re- sults closely similar to those already set forth, and need not be here repeated in detail. The data as to students of more advanced grade are limited, but doubt- less worth summarizing:— Age. Persons. Eyes. Em. M. H. m. ■ Cohn, Univ. of Breslan, 17-27 410 134=32.7 p. c. 244=59.5 p c. 16=37. p c Cohn, Medical students, 108 216 81 37..'j 116 54. 19 8 8 Gartner, Theol. Tiibingen, +19 713 1426 324 22.9 1096 76.9 2 0.2 Derby, H., Graduates, Amherst, 19-28 254 87 34.3 120 47.2 47 IS 5 Collard, Univ. of Utrecht, 17-38 410 820 389 47.4 286 35. 158 J9 2 Van Anrooy, Univ. of Leyden, 17-38 470 939 527 66.23 291 31. 114 12.15 Randall, Med. students, Phila. 19-34 71 142 51 .1*8 5i •• 37 26. —— — ' -^f' . 17-38 2436 4207 1593=37.86 p.c. 2207=52.46 p.c. 392=9.31 p. o. In the first examination of this series H. abs. alone was noted; in the others the H. manifest was sought, but only in that of the writer, wliich ends the list, does the attempt seem to have been made to find the H. total by the ophthalmoscope or other means. In this last case the results were :— 71 Persons. 142 Eyes. Em. 30 = 21.1 p. c, M. 17 = 12.4 p. c. H. 93 = 65.5 p. c. And lor all— 90 Persons. 180 Eyes. Em. 32 18.8 p. c. M. 17 9.44 p. c. H. 131 72.77 p.c., figures in marked contrast to those above.