. Physiological optics : being an essay contributed to the American encyclopedia of ophthalmology . V > 2 Z O 2 i ! 3 3 2 1 O 2 2 3 c ( 2 2 O 1 2 3 £eU Oberlvx. Sr. Fig. 92.—Curves Showing the Lengths of the Radii of Curvature of the Anterior Surface of the Crystalline at Different Distances from the Axis. (After Besio.) accommodative phenomena in a subject having congenital aniridia, hasdrawn the forms of the images due to this surface and they areanalogous to those represented in Fig. 89. In fact the figures ofGrossmann indicate that the flattening is much more pronounced atthe posterior
. Physiological optics : being an essay contributed to the American encyclopedia of ophthalmology . V > 2 Z O 2 i ! 3 3 2 1 O 2 2 3 c ( 2 2 O 1 2 3 £eU Oberlvx. Sr. Fig. 92.—Curves Showing the Lengths of the Radii of Curvature of the Anterior Surface of the Crystalline at Different Distances from the Axis. (After Besio.) accommodative phenomena in a subject having congenital aniridia, hasdrawn the forms of the images due to this surface and they areanalogous to those represented in Fig. 89. In fact the figures ofGrossmann indicate that the flattening is much more pronounced atthe posterior lenticular surface. Furthermore, the observations ofGrossmann show that there is a diminution of the diameter of thecrystalline during accommodation. Likewise, according to the investi-gations of Besio, the increase in the thickness of the lens duringaccommodation is to be attributed to the flattening of the surfacesnear the borders. 185 PHYSIOLOGICAL OPTICS Fig. 93 is drawn from the measurements of a living eye as given byTscherning and show in heavy lines the form of the lens during repose. Fig. 93.—Form of the Crystalline During Repose (- -) and During an Ac- commodation of 8 Diopters ( ). (After Tscherning.) and by dotted lines the shape of the lens during an accommodationof 8 diopters. B 9 10 « 72 \« V i3 V* 9/ iti5 ^^ 0/ if! 27 28 i t= :. > 2 1 c 1 i t Z . Fig. 94.—Curves Indicating the Lengths of the Radii of Curvature of the Anterior Surface of the Dead Crystalline Lens at Different Distances from the Axis. (After Tscherning.) 142. In the light of the foregoing results the hypothesis of vonHelmholtz appears rather improbable, for it is difficult to understandhow a relaxation of the zonula can effect a bulging of certain parts of 186 PHYSIOLOGICAL OPTICS the surfaces while it causes a flattening of other portions. From astudy of the radii of curvature of the anterior surfaces of dead crystal-line lenses, Tscherning has shown that there is a flattening at thec
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