The refraction of the eye; including a complete treatise on opthalmometry; a clinical text-book for students and practitioners . dered. Bothpairs of glasses have been worn with comfort. It is to the reading glasses I wish to call attention in thiscase. The patient, being fifty years of age, was presbyopic tothe extent of 2 D. In the right eye she had simple myopicastigmatism, and either a cross-cylindrical or a sphero-cylin-drical glass could be given. If a cross-cylindrical glass, itwould take the following form: + 2 I), cyl., 125°- , 35°. A glance at Fig. 69 shows why this is so.
The refraction of the eye; including a complete treatise on opthalmometry; a clinical text-book for students and practitioners . dered. Bothpairs of glasses have been worn with comfort. It is to the reading glasses I wish to call attention in thiscase. The patient, being fifty years of age, was presbyopic tothe extent of 2 D. In the right eye she had simple myopicastigmatism, and either a cross-cylindrical or a sphero-cylin-drical glass could be given. If a cross-cylindrical glass, itwould take the following form: + 2 I), cyl., 125°- , 35°. A glance at Fig. 69 shows why this is so. The 1G0 THE REFRACTION OF THE EYE emmetropic meridian at 35° becomes presbyopic by 2 D., andrequires + 2 D. cylindrical glass at right angles to this meridian(at 125°) to correct it ; while the presbyopia of 2 D. neutral-izes 2 D. of the D. of myopia in the meridian at 125°,thus leaving D. of myopia in this meridian still to becorrected, which requires — D. cyl., 35°. But insteadof giving the cross-cylindrical glass, I chose the sphero-cylin-drical + 2 D. — D. cyl., 35°. First, because it was. 145°
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Keywords: ., bookauthordavisa, bookcentury1900, bookdecade1900, booksubjecteye
