Refraction and muscular imbalance, as simplified through the use of the ski-optometer

by Daniel Woolf

Operates and Indicates Automatically

As previously explained, in using the Ski-optometer, it is only necessary to remember that each outward turn of the single reel toward the temporal side of the patient increases the plus power, while the reverse turn toward the patient’s nose decreases it. In fact, no attention need ever be given the register until the required sum-total is secured, it only being necessary to turn the single reel in order to be assured of the unvarying and accurate operation of the instrument.

For convenience, the contour or upper edge of the plate covering the spherical reel has been made to fit the index finger ([Fig. 3]). Hence the operator should note that it requires but one complete turn from extreme side to side, rather than a number of short turns, in order to bring each individual lens into position, thus obtaining the full advantage of the automatic spring-stop. This likewise permits the refractionist to operate the Ski-optometer even though the room is in total darkness.