'HOLOGY, AND VARIETIES. 34 3 and has more frequent complications than the acquired type. The father more frequently passes his defect to tile daugh ter, the mother to the son. Motais (Le Bull. Med., June 12, 'S9).
Eyes of 1000 scholars examined in the private and public schools of Cincinnati and over 300 cases of myopia found. Most of these, probably 70 per cent., were of a low degree, and occurred principally in the elementary divisions, but in the more advanced school-grades there was much larger percentage of the higher de grees of the disease. Dowling (Times and Register, July 25, '91).
From an examination of the eyes of 3002 children attending some of the Aberdeenshire 13oard Schools, it was found that a large percentage (13.4) of myopia exists, especially in the school where education is pushed; while in the country-schools the percentage of myopia is small, never rising above 10 per cent. George Ferdinands (Brit. -Med. Jour., Sept. 12, '91).
From an examination of the eyes of over seven thousand school-ehildren of Antwerp it IN as found that 2.13 per cent. were myopic. Before the age of 10 years 1.16 per cent. had myopia, 1.33 per cent. being boys and 0.99 per cent. girls. After the age of 10 years 3.10 per cent. were myopcs: 3.SS among girls and 2.37 among boys. In well-lighted schools 1.63 er cent of the scholars were found to be p • rnyopes, 1.74 per cent. being girls and 1.57 boys. In badly-lighted schools, 3.75 per cent. of the scholars IN Cl'e 111y1111(1S; of these 4.83 per cent. were girls and 2..67 boys. Bad light and increasing age, with increased demands made upon the eyes by study, are powerful factors in the development and atigi»entation of myopia. De Mets (.1onr. d'llygiene, Sept. 15, '92).
Of 546 eyes examined between the period of infancy and six years of age, 94 were found to be myopic. The latter condition was found to increase very markedly between the thirteenth and twentieth years, NI hell it became station ary. ITerrnlleiser (Sehinidt's .Jahrlmeher, Mar. 15, '93).
The future of many myopic eyes de pumb; 011 the way in which they 111'f• • •••• •• •in 1.t• t .ven I •ol (1111,11'4.41. clerk,.
• - literary men. seam
.. 1N 14•1,. In'Sel el.,. nd I I 1101 0111\ in I lie grt.‘ater •• s •• t• ••t o ttrltt•at ion. among , • • 111 EXCeS ..k work in early lite i, often ae • . rapid increase of refrae • o. in later life it often aggravates 1.);11.klits who 1,,. r continue work in who,e working 1- already too ••Itort. and who lit., to lemythen it by the aid of are encouraging their myopia t r•in a pernicious course. The amount ..f init,t be estimated from the _rah. of myopia, the age of the patient, owl the amount of ehoroidal change al pre-ent. T.) give a bad progno.sis, tf N‘arnim, is sometimes the or only way to prevent its fulfill .t.ent. Prie-tley Huith (Ophthalmic Re n•w. Dee.. 1901 .
Treatment. — .1yopia should be cor Reted by concave lenses, which should bt worn constantly. For young persons tl,e exact optical correction should be rn all the time: although in rare Las4.s it may be better to use a weaker 1,..ns for a time for near work. Pres byr.:.4-s will always require, for near see inz.. a lens sufficiently weaker to make f. 4r their presbyopia. The correcting r - _!ives the myope distinct vision and tl.e vi•ual ranze of the emmetropic eye; ar places the check of accommodative .r rt upon the tendency to excessive convergence. Correcting lenses may be -..:-a-le for those eases in which bi n and therefore strain of c .nvcrz-nce, have previously been given 4-.r where the vision is so imperfect, .! CA i yipz effeet of the correcting FO zreat, that objects will still le held close to the eye to gain the 1.4.nefit of larger retinal images.
The incomplete correction of myopia, unless the glasses are so Is-eak as to be of no material benefit, is extremely gerous. By looking through such lenses obliquely the myope soon finds that he can see farther and more distinctly than by looking squarely through them; and he soon falls into the habit of ing obliquely. I3ut looking obliquely through a lens the pencil of rays re ceived by the eye is rendered astigmatic, and the evils of high uncorrected astig matism are thus entailed. When the full correction for the myopia is worn, look ing obliquely through the lenses makes vision worse and is instinctively avoided.