. Refraction and muscular imbalance, as simplified through the use of the ski-optometer. A B Fig. 26 (A and B)—First position of rotary prisms to determine amount of prism exercise to be employed for building up the weak muscle. The prism should then be still further re-duced until the vertical streak produced bythe Maddox rod directly bisects the muscletesting spot of light. Assuming that this point [76] Refraction and Muscular Imbalance be thirty-eight degrees, which is four degreesless, single binocular vision is Fig. 27—Position of red Maddox rod used in conjunctionwith Fig. 2G
. Refraction and muscular imbalance, as simplified through the use of the ski-optometer. A B Fig. 26 (A and B)—First position of rotary prisms to determine amount of prism exercise to be employed for building up the weak muscle. The prism should then be still further re-duced until the vertical streak produced bythe Maddox rod directly bisects the muscletesting spot of light. Assuming that this point [76] Refraction and Muscular Imbalance be thirty-eight degrees, which is four degreesless, single binocular vision is Fig. 27—Position of red Maddox rod used in conjunctionwith Fig. 2G for prism exercising. For example, sixty degrees of prism power(the combined power of the two rotaryprisms) will usually cause complete distor-tion. Therefore, as outlined in Figure 28,the patient, seeing only out of the right eye,will detect nothing but a white light. Bygradually reducing the strength of the prismbefore the right, which is the good eye, thepatient will eventually see a red streak off tothe left. A continued and gradaal reductionto a point where the red streak bisects thewhite light, will determine how much prismpower is required for the patient to obtainsingle bmocular vision, thus establishing the [77] Refraction and Muscular Imbalance same image at the same time on each fovea orretina (Fig. 20). This has taught the patient to do that whichhe has never before accomplished. There-fore, after having been taught how to makethe two eyes work in relation to each other,the natural tendency thereafter wil
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