CONTENTS

Page
Chapter I
Ski-optometer Construction[ 1]
Convex Spherical Lenses[ 2]
Operates and Indicates Automatically[ 6]
Concave Spherical Lenses[ 7]
Chapter II
Cylindrical Lenses[10]
Obtaining Correct Focus[11]
Why Concave Cylinders Are Used Exclusively[14]
Transposition of Lenses[14]
Chapter III
How the Ski-optometer Assists in Refraction[17]
The Use of the Ski-optometer in Skioscopy[17]
A Simplified Skioscopic Method[20]
Employing Spheres and Cylinders in Skioscopy[22]
Use of the Ski-optometer in Subjective Testing[23]
A Simplified Subjective Method[24]
Procedure for Using Minus Cylinders Exclusively[26]
Constant Attention Not Required[29]
Chapter IV
Important Points in Connection with the
Use of the Ski-optometer[30]
Elimination of Trial-Frame Discomfort[30]
Rigidity of Construction[31]
How to Place the Ski-optometer in Position[32]
Cleaning the Lenses[33]
Accuracy Assured in Every Test[34]
Built to Last a Lifetime[35]
Chapter V
Condensed Procedure for Making Sphere and
Cylinder Test with the Ski-optometer[37]
Subjective Distance Test[37]
Subjective Reading Test[40]
Chapter VI
Muscular Imbalance[41]
The Action of Prisms[42]
The Phorometer[43]
The Maddox Rod[44]
Procedure for Making the Muscle Test[45]
Binocular and Monocular Test[47]
Chapter VII
The Binocular Muscle Test[48]
Made with the Maddox Rod and Phorometer[48]
Esophoria and Exophoria[50]
Making Muscle Test Before and After Optical Correction[52]
When to Consider Correction of Muscular Imbalance[53]
Four Methods for Correction of Muscular Imbalance[54]
The Rotary Prism[54]
Use of the Rotary Prism in Binocular Muscle Tests[56]
Chapter VIII
The Monocular Duction Muscle Test[58]
Made with Both Rotary Prisms[58]
Locating the Faulty Muscle[58]
Adduction[59]
Abduction[61]
Superduction[62]
Subduction[63]
Procedure for Monocular Muscle Testing[64]
Diagnosing a Specific Muscle Case[65]
Chapter IX
First Method of Treatment—Optical Correction[70]
Esophoria[70]
Treatment for Correcting Esophoria in Children[72]
How Optical Correction Tends to Decrease 6°
Esophoria in a Child[74]
Chapter X
Second Method of Treatment—Muscular Exercise[75]
Made with Two Rotary Prisms and Red Maddox Rod[75]
Exophoria[75]
An Assumed Case[78]
Effect of Muscular Exercise[80]
Home Treatment for Muscular Exercise—
Square Prism Set Used in Conjunction with
the Ski-optometer[82]
Chapter XI
Third Method of Treatment—Prism Lenses[84]
When and How Employed[84]
Prism Reduction Method[85]
Chapter XII
A Condensation of Previous Chapters on the Procedure
for Muscle Testing with the Ski-optometer[87]
Four Methods of Treating an Imbalance Case when
the Preceding One Fails[90]
Prisms[92]
Cyclophoria[92]
Chapter XIII
Cyclophoria[93]
Made with Maddox Rods and Rotary Prisms[93]
Chapter XIV
Cycloduction Test[99]
Made with the Combined Use of the Two Maddox Rods[99]
Treatment for Cyclophoria[102]
Chapter XV
Movements of the Eyeballs and their Anomalies[105]
Monocular Fixation[105]
Binocular Fixation[106]
Orthophoria[107]
Heterophoria[107]
Squint[108]
Varieties of Heterophoria and Squint[109]
Chapter XVI
Law of Projection[114]
Suppression of Image[115]
Monocular Diplopia[115]
Table of Diplopia[116]
Movement of Each Eye Singly[117]
Subsidiary Actions[118]
Field of Action of Muscles[120]
Direction of the Gaze[120]
Primary Position—Field of Fixation[121]
Binocular Movements[121]
Parallel Movements[122]
Lateral Rotators[123]
Eye Associates[124]
Movements of Convergence[125]
Movements of Divergence[125]
Vertical Divergence[126]
Orthophoria[126]
Heterophoria[126]
Subdivisions[126]
Chapter XVII
Symptoms of Heterophoria[128]
Treatment[130]
Destrophoria and Laevophoria[132]

The demands of the day for maximum efficiency in the refracting world are largely accountable for the inception, continuous improvement and ultimate development of the master model Ski-optometer.

The present volume, dealing with the instrument’s distinctive operative features, has been prepared not only for Ski-optometer users, but also for those interested in the simplification of refraction and muscular imbalance.

The author is indebted for invaluable counsel, to

Louis J. Ameno, M.D., New York.
E. LeRoy Ryer, O.D., New York.
Jos. D. Heitger, M.D., Louisville, Ky.
W. B. Needles, N.D., Kansas City, Mo.

INTRODUCTORY

While in a measure the conventional trial-case still serves its purpose, so much of the refractionist’s time is consumed through the mechanical process of individually transferring the trial-case spheres and cylinder lenses, that far too little thought is given to muscular imbalance, notwithstanding its importance in all refraction cases.

Dr. Samuel Theibold, of Johns Hopkins University, in a recent address before the American Medical Association, stated that the average refractionist was inclined to devote an excess of time to general refraction, completely overlooking the important test and correction of muscular imbalance. If the latter is to be at all considered, general refraction must be simplified—without impairing its accuracy—a result that is greatly facilitated through the use of the Ski-optometer.

One must admit that tediously selecting the required trial-case lens—whether sphere, cylinder or prism—watching the stamped number on the handle—continual wiping and inserting each individual lens in a trial-frame is a time-consuming practise. This is readily overcome, however, through the employment of the Ski-optometer.