Report of the fourth international ophthalmological congress, held in London, August, 1872 / published by a committee composed of G. Critchett [and others] ; the papers arranged, and the text and translations revised by Henry Power.

Date:
1873
Catalogue details

Licence: Public Domain Mark

Credit: Report of the fourth international ophthalmological congress, held in London, August, 1872 / published by a committee composed of G. Critchett [and others] ; the papers arranged, and the text and translations revised by Henry Power. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    By the arrangement described above, the surgeon is enabled to turn the disc round without removing the ophthalmoscope from his eye, thus securing the great advantage of an uninterrupted succession of images of the fundus; by this means he computes with ease the exact amount of ametropia in cases either of hypermetropia or myopia: an advantage of especial value in estimating the relative refraction of each meridian in the case of an astigmatic patient. The mirror, which unscrews from the handle, is about the size of a pennypiece, and is so flat that it can be easily carried, together with its discs, in an ordinary purse or pocket-book, thus obviating the necessity of a separate case. I have also had an ophthalmoscope made on the same principle, with one unchangeable disc, containing three convex lenses of the respective values of 30, 20, 10 Paris inches; and four concave lenses—viz., 30, 20, 10, 5 inches focal length, as being the most useful aids in ordinary ophthalmoscopic examination.