[Unusual perceptions with the Pola Test in a case of esotropia with anomalous correspondence]

That the Pola test figures of heterophoric subjects with fixation disparities are described as deformed at times, was published by H. J. Haase two decades ago. The main subject in this publication is a 13-year-old boy with early childhood convergent strabismus, in which the "squint therapy" which was used at that time, did not change the angle of squint and the anomalous correspondence to any extent. The corrected visual acuity was the same bilaterally, 1.0 to 1.1. If the esotropic eye position was corrected as well as possible with prisms to the objective angle, a change between diplopia and binocular fusion occurred; occasionally even to "normal corresponding" fusion with correct stereopsis. In the transition phases the test level appeared to be more or less drawn out in width, and the half figures underwent all kinds of "somersaults". Binocular macropsia and monocular micropsia and macropsia, and also polyopia and unusual depth effects were described. Confusion did not occur; all pictures had form. These rare phenomena were interpreted as a competition between established anomalous and latent normal correspondence. This communication should stimulate further observations of this type and, should the occasion arise, lead to experimental research.