. Refraction and muscular imbalance, as simplified through the use of the ski-optometer. 3-B — Inner spherical disk containing Cx. sphericals, automatically turns within 3-C — Supplementary spherical disk. By means of a concealed tooth gear, an innerdisk is automatically picked up, placing itsfirst lens + in position (Fig. 3b). This+ spherical lens remains stationarywhile the outer disk again revolves, addingto it the original +.25, +.50, +.75 and +, [3] Refraction and Muscular Imbalance

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