The concept that anomalous correspondence is more deeply rooted when more tests indicate its presence was subjected to experimental investigation and was found to be unsupported by the results. Two thirds of the (93) subjects showed the same diagnosis of retinal correspondence on at least four of five different tests. When there was diasgreement between the amblyoscope and afterimage tests, anomalous correspondence was found just as often on one test as on the other. Diagnostic disagreement between tests for retinal correspondence is adequately explained by measurement error, unsteady eccentric fixation, and change in position of the eyes.
Flom MC, Kerr KE. Determination of Retinal CorrespondenceMultiple-Testing Results and the Depth of Anomaly Concept. Arch Ophthalmol. 1967;77(2):200-213. doi:10.1001/archopht.1967.00980020202010