Manual of instructions for the guidance of army surgeons in testing the range and quality of vision of recruits, and in distinguishing the causes of defective vision in soldiers / by T. Longmore.

Longmore, Sir Thomas, 1816-1895.

Date:: [1864]

Credit: Manual of instructions for the guidance of army surgeons in testing the range and quality of vision of recruits, and in distinguishing the causes of defective vision in soldiers / by T. Longmore. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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$nerve tissue, or that form of atrophy which used to be called cerebral amaurosis.” The amount of change of direction which the vessels lying on the optic papillary surface assume in turning over the scheral margin to ramify on tlie retina indicate, to a certain extent, the dejith of the excavation. 4. Simple IlypERiEMiA or the Optic Nerve. Ophthalmoscopic Appearances.—Hyperajmia, which may be due to simple congestion, or to inflammation concurrent with retinitis, shows itself by an exaggerated colouring of the disc. The. depth of colour varies according to the amount of hyperEemia, from a rose blush to greyish red; and as the colour increases, the papilla becomes less conspicuous from loss of contrast with the general colour of the fundus. Hyperaemia from simple congestion is seen very frequently in persons Avho are subjecting their eyes to excessive strain at near objects, especially when an abnormal con- dition of refractive power is not corrected by suitable lenses. In such cases the pinkiness may be limited in appearance to the colliculus, or to a part only of the papilla, or the Avhole disc may appear injected. Diagnostic Signs.—The appearances described, together with the absence of the indications of serious lesions in the other structures, sufficiently distinguish this condition. The appearances will in many cases be confined to the nerve of one eye. 5. Inflammation of the optic Nerve and Eetinitis. Ophthalmoscopic Appearances.—In inflammation, the indications of hyperaemia just described are folloAved by a train of appearances which vary according as inflammatory products are effused, or more remote consequences developed. Ixiflammation of the optic nerve is necessarily so connected with retinitis, that, as already men- tioned, they can only be noticed together. When inflammation has supervened, not only is the papilla less conspicuous, owing to its state of injection, but its circumferential limit becomes less defined. This obscurity appears owing to a haze covering the papilla, like, as it were, a veil extending over it, and becoming blended with the surrounding fundus. The optic entrance a])pears magnified, yet uncertain. Elevation, or intra-ocular projection of the papilla, has also been noticed as an accompaniment of inflam-$