. Refraction and muscular imbalance, as simplified through the use of the ski-optometer. Instead of employing a battery of con-cave lenses similar to the convex battery pre-viously described, the instruments operationis greatly simplified through the use of a neu-tralizing process. In short, the Ski-optometer only containstwo concave lenses to obtain its entire series—namely, a — and a — sphere ()—first setting the pointer of the sup-plementary disk at—6. sphere, then setting theindicator of the spherical battery at +6. Thus zero (or piano) is obtained, the plusneutralizing the mi
. Refraction and muscular imbalance, as simplified through the use of the ski-optometer. Instead of employing a battery of con-cave lenses similar to the convex battery pre-viously described, the instruments operationis greatly simplified through the use of a neu-tralizing process. In short, the Ski-optometer only containstwo concave lenses to obtain its entire series—namely, a — and a — sphere ()—first setting the pointer of the sup-plementary disk at—6. sphere, then setting theindicator of the spherical battery at +6. Thus zero (or piano) is obtained, the plusneutralizing the minus. By merely turning the plus or convex spher-ical reel inward, or toward the patients nose,the convex power is then decreased, naturallyincreasing the concave value or total minuslens power. For example, if the spherical in- [7] Refraction and Muscular Imbalance dicator shows +, when the —6D. lens isplaced behind it, the lens value at the sightopening will be —ID (Fig. 6). If re-quired, the refractionist may continue on thisplan until only the —6D. lens Fig. 6—With this indicator of supplementary disk, set at—, Sph. and spherical indicator at +—lens valueat sight opening is — Sph. This simple arrangementmakes it possible to operate the Ski-optometer with butSingle Reel for both plus and minus sphericals. Should concave power stronger than — desired, by placing the pointer of the sup-plementary disk at —12D. Sph. and proceed-ing to neutralize as before, all the concavepowers up to —12D. in quarters are similarlyobtained. For the convenience of the opera-tor, all minus or concave spherical powers areindicated in red; while plus, or convex pow-ers, are indicated in white. [8] Refraction and Muscular Imbalance The instrument is also provided with anopaque or blank disk which is brought intoposition before the sight opening by settingthe pointer of the supplementary disk atshut (Fig. 3c.) Summing up, all plus and minus sph
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Keywords: ., bookcentury1900, bookdecade1920, bookidrefractionmu, bookyear1921
