. A treatise on the diseases of the eye. teries diminished in size, and, here and there,hidden by the exudation. Fig. 14 shows the condition of the same optic nervetwo years later, when consecutive atrophy had supervened. The uniformly opaquetint of the disk, as well as its somewhat undefined margin, help to distinguish it ata glance from the progressive form of atrophy (Fig. 12). Moreover, although theveins are less dilated than in Fig. 13, they yet retain a certain degree of tortuosity. Figs. 15 and Excavation of the Optic Nerve (p. 575). In these two figures are observed di
. A treatise on the diseases of the eye. teries diminished in size, and, here and there,hidden by the exudation. Fig. 14 shows the condition of the same optic nervetwo years later, when consecutive atrophy had supervened. The uniformly opaquetint of the disk, as well as its somewhat undefined margin, help to distinguish it ata glance from the progressive form of atrophy (Fig. 12). Moreover, although theveins are less dilated than in Fig. 13, they yet retain a certain degree of tortuosity. Figs. 15 and Excavation of the Optic Nerve (p. 575). In these two figures are observed different degrees of glaucomatous present all the characteristic features of this disease, but in Fig. 15 they areless marked than in Fig. 16, in which the cup is much deeper and more each case, the disk is surrounded by a pale, light girdle, its color is much darkerat the periphery than in the centre, and the retinal vessels are more or less con-siderably bent or interrupted at the edge of the papilla. Plate Ifter LieLreiclns Atlas. Th 0 s . SELECTIONS FRO)I THE TEST-TYPES PROF. EDWARD JAEGER, OF VIEXXA. DR. H. SXELLEX, OF UTRECHT. TEST-TYPES. [The test-types of Prof. Jaeger are formed of ordinary printers types, rang-ing in size from No. 1 (Diamond) to No. 20 (8-line Roman). They arevaluable as a means of ascertaining the fluency with which small print can be read,and whether the patients sight is improving or otherwise under treatment, and alsoas a standard of comparison between different individuals. They will frequentlybe found referred to in published reports of cases. The smallest visual angle which permits of the distinct perception of an object isfive minutes (see p. 620). With this angle as a basis, Dr. Snellen has formedhis series of test-types. Each letter is square, and each line of the letter has awidth equal to one-fifth of its height. The figures above each series of lettersindicate the distance in feet from the eye
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Keywords: ., bookcentury1800, booksubjecteye, booksubjecteyediseases, bookyear
