. Refraction and how to refract : including sections on optics, retinoscopy, the fitting of spectacles and eye-glasses, obscured by areas of darkness,which make it extremely difficult to study the refraction,and the observer will have to change his distance repeat-edly to find clear spaces as close to the center of the pupilas possible, as it is this portion of the pupillary area thatthe patient will see through when the mydriatic effect passesaway. The kinetoscopic picture obtained by mo\ing themirror so as to describe a circle at the periphery of thepupillary space is quite diagnostic
. Refraction and how to refract : including sections on optics, retinoscopy, the fitting of spectacles and eye-glasses, obscured by areas of darkness,which make it extremely difficult to study the refraction,and the observer will have to change his distance repeat-edly to find clear spaces as close to the center of the pupilas possible, as it is this portion of the pupillary area thatthe patient will see through when the mydriatic effect passesaway. The kinetoscopic picture obtained by mo\ing themirror so as to describe a circle at the periphery of thepupillary space is quite diagnostic of the corneal result is obtained should be kept for reference ina postcycloplegic manifest refraction, as it will not alwaysdo to order the glasses while the eye has its pupil patient may choose a slightly different correction insuch cases, after the pupil regains its accustomed size. Irregular Lenticular Astigmatism.—This is oftenmore uniform than the corneal \arict\, and is characterizedby faint striiu in the lens, pointing in toward the center. IfIS I70 REFRACTION AND HOW TO the Striae are not very faint, they may be recognized with theophthahnoscope, even before any cycloplegic has been Movement (see Fig. 149).—This is a condi-tion where there are two bands of Hght present, usually inthe horizontal meridian or inclined a few degrees the mirror in the vertical meridian, a band of lightis seen to come from above and to meet another band, whichcomes from below; while these two bands are approaching,the dark space between them gradually disappears, until thetwo bands unite and form one bandacross the pupil in or approximat-ing the horizontal meridian. Thismovement of the bands is likenedto the action of the blades of a pairof scissors, and hence the refract a case of this character,the observer must proceed slowlyand endeavor to neutralize thehorizontal meridian first, and thenadd minus c}linde
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Keywords: ., bookcentury1900, bookdecade1900, bookidref, booksubjecteyeglasses
