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