Refraction and Muscular Imbalance
Reading edition
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
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.