Ocular refraction and the shadow test . he two principal meridians. One of themwill be parallel to the direction of the band, the other will be at rightangles to it. In plate 140, the principal meridians are indicated i^ 11 so Mm s^ni^^H^I II ^ ^ ^ llllll ^ ^ 11 iH^^^^Hi SI alllH v^- a lUHIPIII^^^Hl 11^ W^ ^^ tsH^jj/t^^^m WL i I^^^F^^ ^ <-^^^^^K[^ ^dHI^IBi Plate 144. Method of locating the myopic far point in myopia without the aid ofthe working distance with a tape measure held by patient and operatorin the authors refracting room. R E T I N O S C t) P Y. 185 the vertical and horizontal di
Ocular refraction and the shadow test . he two principal meridians. One of themwill be parallel to the direction of the band, the other will be at rightangles to it. In plate 140, the principal meridians are indicated i^ 11 so Mm s^ni^^H^I II ^ ^ ^ llllll ^ ^ 11 iH^^^^Hi SI alllH v^- a lUHIPIII^^^Hl 11^ W^ ^^ tsH^jj/t^^^m WL i I^^^F^^ ^ <-^^^^^K[^ ^dHI^IBi Plate 144. Method of locating the myopic far point in myopia without the aid ofthe working distance with a tape measure held by patient and operatorin the authors refracting room. R E T I N O S C t) P Y. 185 the vertical and horizontal directions. In measuring the refractionof an astigmatic eye, the transit of the light must follow these twomeridians and no others. Plate 145, illustrates astigmatism at an oblique axis, the lightband is seen passing from the pupil and followed by the shadow, thestraight band of separation is clearly shown. Suppose that in the retinoscopic examination of an eye the ap-pearance of the in the pupil is similar to that shown in plate. Plate 145-Astigmatism at an oblique angle. The light band is seen just leaving the pupil. 140. If a transit of the light in the direction of the band, showsslight movement witli the movement of the light area, hypertnetropiais indicated in that meridian. If a transit of the meridian at rightangles to the band shows movement of the light band against X.\i^movement of the light area, myopia is indicated in that working distance being one metre. Interpose a + D. S , and it will be assumed that this chokesthe in the horizontal meridian. Now the vertical meridianshowed myopia before any lens was interposed, the -^ D. S. i86 OCULAR REFRACTION. therefore renders this meridian more myopic. No matter, leave the+ D. S. before the eye. Concave value is wanted in the vertical meridian, but it is desirednot to disturb the horizontal meridian in which the reflex is chokedby the + U S. This may be accomplished by using
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