Retinoscopy (or shadow test) in the determination of refractions at one meter distance, with the plane mirror / by James Thorington.

  • James Thorington
Date:
1906
Catalogue details

Licence: In copyright

Credit: Retinoscopy (or shadow test) in the determination of refractions at one meter distance, with the plane mirror / by James Thorington. Source: Wellcome Collection.

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    or lower it or move it toward or away from the patient, as necessary (see Fig. 3). When gas or electric light is not at hand, a student’s oil-lamp, with a suitable light-screen,!; will answer every purpose (see Fig. 4). The light-screen, or cover chimney, is ’made of one- eight inch asbestos, and of sufficient size (six centimeters Fig. 3. in diameter by twenty-one in height) to fit over the glass chimney of the Argand burner (see Fig. 5). Attached to the screen are two superimposed revolving discs that furnish foyr round openings, respectively five, ten, twenty, and thirty millimeters, any one of which may be turned into place as occasion may require. Care should be taken that the opening used is placed opposite to the brightest, and never opposite to the edge of the blue part
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