Defects of sight and hearing : their nature, causes, prevention, and general management / by T. Wharton Jones.

  • Thomas Wharton Jones
Date:
1859
Catalogue details

Licence: Public Domain Mark

Credit: Defects of sight and hearing : their nature, causes, prevention, and general management / by T. Wharton Jones. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    rial of the proper substance of the lens. It may he looked upon in some degree as a natural change with the advance of life, analogous to the hairs becoming gray or white. But there are some circumstances which especially predispose to the complaint, such as hereditary tendency, rheumatic constitution, habitual exposure to strong fires, &c. When once begun to form, it may be prognosticated, that the opacity will go on to increase until all useful vision is prevented in the eye. And it may also be prog- nosticated, that the other eye, if not already affected, will become so likewise. How rapid or how slow the pro- gress to loss of useful vision may be, cannot, however, be prognosticated—it may be months, or it may be years. Restoration of vision can be effected only by an opera- tion, by which the opaque lens shall be removed from its situation to below the level of the pupil, (the operation of displacement,) or extracted from the eye altogether, (the operation of extraction?) [In this city the operation by division or absorption is generally preferred, being well adapted to the removal of soft or fluid cataract.] These operations have for their common object the re- moval of the opaque body from behind the pupil, so that the rays of light may be again allowed to pass on to the retina- To make up for the loss of the crystalline lens, the use of spectacles, with strong convex glasses, is required after recovery from the operation. In cases fit for the operation, a successful result may be expected in a large majority. Perhaps, out of twelve cases operated on, excellent sight may be recovered in eight, less o-ood sight in two or three, whilst one or two will prove unsuccessful. 5