Ski-optometer Master Model 215
Embodying in a Single Instrument, in Convenient Form,
Cylindrical and Spherical Lenses, in Combination
with Appliances for Testing and Correcting
Muscular Imbalance.
Refraction and
Muscular Imbalance
As Simplified Through the Use
of the Ski-optometer
By
DANIEL WOOLF
WOOLF INSTRUMENT CORPORATION
New York: 516 Fifth Avenue
Copyright 1921
By WOOLF INSTRUMENT CORPORATION
Published by
Theodore S. Holbrook
New York