The refraction of the eye; including a complete treatise on opthalmometry; a clinical text-book for students and practitioners . xis of the cylinder in the right eye varied 5° from thereading of the ophthalmometer; second, I converted the cross-cylinder in the left eye into a sphero-cylinder, — a minussphere with a plus cylinder, —and for three reasons: (a) tomake the cylinder correspond to the right eye ; (ft) because,in this case, it is a lighter glass than the sphero-cylinder with aplus sphere and a minus cylinder; and (c) a cheaper glass. [LLUSTRATIVE CASES ls«.i And this brings me to spea
The refraction of the eye; including a complete treatise on opthalmometry; a clinical text-book for students and practitioners . xis of the cylinder in the right eye varied 5° from thereading of the ophthalmometer; second, I converted the cross-cylinder in the left eye into a sphero-cylinder, — a minussphere with a plus cylinder, —and for three reasons: (a) tomake the cylinder correspond to the right eye ; (ft) because,in this case, it is a lighter glass than the sphero-cylinder with aplus sphere and a minus cylinder; and (c) a cheaper glass. [LLUSTRATIVE CASES ls«.i And this brings me to speak, in a general way. in referenceto Buch cases as tin- present one, where there is a mixed astig-matism in one eye and simple or compound astigmatism in theother. In converting the cross-cylinders into sphero-cylinders,some regard must be had that the character (plus or minus) ofthe cylinder in the transposed glass correspond to the cylinderin the opposite eye. Because, as a rule, a plus cylinder on oneeye and a minus cylinder on the other do not work as wellas when both are positive or negative. This point should be. R. E. L. E. borne in mind, in converting cross-cylinders; and, unless by sodoing the weight of the glass is greatly increased, cylinders ofa like character should be given. Sometimes in such cases itis better to give the cross-cylinder in the mixed astigmatic eye,especially if the astigmatism is of large amount, rather thanconvert it into a sphero-cylinder, either with plus sphere andminus cylinder, or minus sphere and plus cylinder: and. byputting the different combinations in front of the eye for a fewmoments, the patient will often make the choice for himself. 190 THE REFRACTION OF THE EYE Cask LXXY. Mired axtiymatism with the rule right eye;Hypermetropic astigmatism with the rule left eye ; Marked asthe-nopia; Spasm of accommodation ; Atropine instilled; Relief withglasses. — February 17, 1894, Pauline J., aged thirty years, isin good general health, b
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