Text-book of ophthalmology . nt is not due to lack of use, and is, in fact,the cause, not the result of the myopia. See page 874.—D.] In hypermetropic eyesthe opposite condition exists. In these, Mailers portion of the ciliary muscle is hyper-trophied by constant accommodative effort, and thus the whole muscle is increased insize; and hence the entire ciliary body projects farther toward the interior of the eye(Fig. 384). A comparison of Figs. 383 and 384 with each other and with Fig. 382, whichrepresents the ciliary body of an emmetropic eye, shows how the shape of the sinus ofthe anterior ch
Text-book of ophthalmology . nt is not due to lack of use, and is, in fact,the cause, not the result of the myopia. See page 874.—D.] In hypermetropic eyesthe opposite condition exists. In these, Mailers portion of the ciliary muscle is hyper-trophied by constant accommodative effort, and thus the whole muscle is increased insize; and hence the entire ciliary body projects farther toward the interior of the eye(Fig. 384). A comparison of Figs. 383 and 384 with each other and with Fig. 382, whichrepresents the ciliary body of an emmetropic eye, shows how the shape of the sinus ofthe anterior chamber is determined by th form of the ciliary body. In a myopic eyethe sinus is deeper, in a hypermetropic eye shallower, than in the emmetropic eye. Thisrelation, which can also Ik; observed macroscopically in the living eye, is held to be ofimportance in the genesis of glaucoma. We know that in the atter condition, owingboth to the swelling of the ciliary processes and also to the thickening of the iris that MYOPIA 871 B. temporal nasat Fig. 381.—Optic-nerve Entrance in Myopia. A. Ophthalmoscopic Image of the Papilla.—The papilla, b-c, is of the shape of an ellipsewith its long axis vertical. In its outer half it shows the large physiological excavation, upon whosefloor are visible, the gray stipplings of the lamina cribrosa, while the central vessels ascend on theinner wall of the excavation. Adjoining the inner border of the papilla and not sharply separatedfrom it, is the bright crescent, a-b (distraction crescent). This is of a white color, while the papillaitself is reddish. The crescent is covered with brownish, elongated markings, representing remainsof the stroma pigment of the chorioid. The temporal border of the crescent is sharply denned, andthe chorioid adjoining it is somewhat more pigmented than usual. On the other hand, the chorioidin the vicinity of the nasal border of the papilla shows a somewhat lighter coloration in the space be-tween c and d, so that
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecteye, booksubjectophth
