This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ...are due to the white of the sclerotic. On the outer side of the disc is a slight crescent, caused by the choroidal opening being rather larger than the sclerotic ring, so that a small portion of the sclerotic is here exposed. PLATE II. Fig. 1.--Fundus of a very dark child, aged 10; skin dark, hair black, eyebrows and ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ...are due to the white of the sclerotic. On the outer side of the disc is a slight crescent, caused by the choroidal opening being rather larger than the sclerotic ring, so that a small portion of the sclerotic is here exposed. PLATE II. Fig. 1.--Fundus of a very dark child, aged 10; skin dark, hair black, eyebrows and eyelashes black; irides dark brown. Erect image. Left eye. The striation around the disc is unusually distinct. The stippling of the lamina cribrosa can be seen in the centre of the disc. Fig. 2.--Right fundus of a child, aged 10 years; hair dark brown, eyebrows brown, eyelashes black; irides dark brown. Inverted image. The tissue of the choroid contains a large quantity of very dark pigment, which causes the interspaces between the choroidal vessels to appear very dark--much darker than the vessels themselves. The pigment in the epithelial layer of the retina must be of a lighter colour than usual, to allow one to see through it on to the deeper layers of the choroid. There is a well-marked physiological cup present. The halo around the macula is due to reflection. choroid. At the macula, its thinnest part, it is only 1 mm. thick. The retina anterior to its epithelial layer is transparent; this is necessarily the case, since it is so constructed, that rays of light entering the eye have to pass through to its deeper parts in order to reach the layer of rods and cones on which images must be formed. In dark-complexioned persons a sort of shimmer or bloom maybe sometimes detected, especially in the region of the macula; occasionally a striated appearance is visible at the upper and lower margins of the disc, spreading a considerable way over the retina. This is due to the nerve-fibres being slightly visible over the part where they are thickest, ..
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