Ocular refraction and the shadow test . Hyper ned by p ate I 42. no cope,he rig The 1 ght a rea ami 00 D S and the reflex reflex bolh passing to with, interpose a -f i 00 U, S. and the reflex will be found tobe choked because the emergent parallel rays of the emmetropiceye will be brought to a focus at the working distance of one the third eye, the movement of the reflex against will be choked by interposing a— D. S , the emergent rays whichconverged to a focus at ten inches being brought to a focus at the R E T I N O S C O P Y. 179 working distance of forty inches. The fourth ey
Ocular refraction and the shadow test . Hyper ned by p ate I 42. no cope,he rig The 1 ght a rea ami 00 D S and the reflex reflex bolh passing to with, interpose a -f i 00 U, S. and the reflex will be found tobe choked because the emergent parallel rays of the emmetropiceye will be brought to a focus at the working distance of one the third eye, the movement of the reflex against will be choked by interposing a— D. S , the emergent rays whichconverged to a focus at ten inches being brought to a focus at the R E T I N O S C O P Y. 179 working distance of forty inches. The fourth eye in which themovement of the reflex is with will be choked by interposinga + 3 00 D S., the emergent rays which diverged being brought toa focus at the working distance of one Myopia as indicated by tlie relinoscope. The light area on the face is passing cff the pupilto the right, while the rtflex ismoving to the left in the pupil. This movement of tiie retinal reflex in the pupillary area, withor against the movement of the light area, is governed by the follow-ing conditions With a plane retinoscope, if the image observed iserect, the movement will be with; if the linage is inverted themovement will be • against. When no movement occurs, the reflexbeing choked, the reversal point of the image is indicated, there-fore :— In the examination of an eye with a plane retinoscope if thereflex movement is against, the observer is beyond the reversal point;if the movement be with, the observer is inside of the reversal will be seen that the object of the retinoscopic examination is tolocate the reversal point at some definite working distance. Roughly estimated it is usual to say that movement against indi-cates myopia, movement with hypermetropia, th
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