Figs. 31-36—Diagram showing how streaks appear to patient, as produced by the Maddox rods in testing for cyclophoria.
Should there be no cyclophoria of the right eye, the streaks will appear in a horizontal plane parallel to each other ([Fig. 31]).
Should the red streak appear horizontally to the left eye, and the white streak seen by the right eye appear at an angle therewith, cyclophoria of the right eye would be indicated ([Fig. 32]).
In brief, should the white streak dip towards the patient’s left side, the case would be one of right plus cyclophoria ([Fig. 32]); whereas right minus cyclophoria would be indicated should the white streak dip to the patient’s right side ([Fig. 33]).
Next, setting the rotary prism of 8 degrees, placed base up before the patient’s left eye, the red streak should appear below the white one. Should the two streaks appear horizontally, parallel with each other, there would be no cyclophoria of the left eye ([Fig. 34]).
If, however, the upper or white streak should appear horizontal, and the lower or red streak at an angle therewith dipping toward the patient’s right side, the left eye would be cyclophoric and the case would be one of left plus cyclophoria, as the chart indicates ([Fig. 35]).
Should the red streak dip in toward the patient’s left side, left minus cyclophoria would be designated ([Fig. 36]).
The patient would instinctively describe, with pointed finger and hand motion, the position of the “dipping” line just as one would describe a spiral staircase. Should this test determine that no cyclophoria exists in either eye, there would be no necessity for further tests.
Some authorities claim that both Maddox rods should be of the same color, so as to more readily assist the patient to fuse the two objects. If the reader so desires, he can readily place a red lens from the trial-case in the forward cell of the instrument.