How useful is anomalous correspondence?
In anomalous retinal correspondence (ARC), retinal points in the right and left eyes which receive stimuli from one object in space have the same visual direction despite a manifest motor deviation. The mode of cooperation of these anomalously corresponding retinal points depends on their relative eccentricity or their relative functional level. If there is a great difference, as for the most part in large angle strabismus, the retinal point with less eccentricity and better resolution will prevail, while the other will be suppressed. This leads to a second area of high resolution in the binocular visual field with a possibly irritating effect. In microtropia, anomalous corresponding retinal points have functionally different levels only in the very centre of the visual field. ARC provides in this case a binocular cooperation very similar to normal fusion. To an individually different degree, ARC can adapt to new squint angles, which makes squint surgery possible without postoperative diplopia, but a change to normal binocularity with stable interocular connections can not be achieved. ARC enables the heterotropic patient to see with both eyes simultaneously without diplopia by a regionally changing use of inhibition and anomalous fusion in the interest of the best possible perception.