This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...the right eye tends to turn outward, the image of the light falling in the lower and outer portion of the retina seems to be above and to the left of the real light. The amount which the eye turns outward is shown by the strength of a second prism, base inward, which brings the two lights into a ...
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...the right eye tends to turn outward, the image of the light falling in the lower and outer portion of the retina seems to be above and to the left of the real light. The amount which the eye turns outward is shown by the strength of a second prism, base inward, which brings the two lights into a vertical line. It is easy to see that this experiment could be varied in many ways. One of these is to arrange a scale for the speedy and accurate determination of the position of the eyes, such as has been constructed by Herbert (B 533). This scale consists of a black background with several white squares to the right, left, up, and down respectively from a central square, thus forming a cross, each spot being one centimeter square and so arranged that the separation of each square is Fig. 158.--Herbert's arrangement of dots for testing and measuring heterophoria. equivalent to a deflection of one prism diopter. If the squares are to be viewed at a distance of five meters, they must be drawn five centimeters from center to center. If, however, that distance from the scale to the patient is not convenient, any other may be chosen, the rule being that for every decrease of one meter, the distance between the squares must be decreased one centimeter, and for every increase of one meter the squares must be separated one centimeter. Figure 158 illustrates the arrangements of the dots or small squares. White squares can be cemented on black, or black ones on a white back Fig. 159.--Same arrangement in orthophoria with a prism of five degrees base down before right eye. ground. The scale should be hung up in a good light, opposite a window if possible, the center of the scale being on the same level as the patient's eyes. By placing a 5-degree prism...
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Add this copy of The Muscles of the Eye, to cart. $47.77, very good condition, Sold by Midtown Scholar Bookstore rated 5.0 out of 5 stars, ships from Harrisburg, PA, UNITED STATES, published 1992 by Classics of Ophthalmology Librar.
