Chapter I: Front Matter

Transcriber’s Notes:

Underscores “_” before and after a word or phrase indicate _italics_
in the original text.
Small capitals have been converted to SOLID capitals.
Illustrations have been moved so they do not break up paragraphs.

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

CONTENTS

CHAPTER I Page
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