Monocular adaptation of the saccadic system and vestibulo-ocular reflex

This study asks whether or not adaptation of saccades and the VOR is constrained to be conjugate by Hering's Law. Changes in saccades and the VOR produced by surgically weakening one of the horizontal recti by recession or tenotomy were examined in monkeys with the affected eye patched. After the restoration of vision a rapid monocular recalibration of both saccades and the VOR was observed in preparations with a small or moderate muscle weakening. Preparations with a severe weakening exhibited little monocular adaptation but when the normal eye was patched exhibited a strong conjugate adaptation. Thus the results indicate that saccades and the VOR have the capacity for monocular recalibration but that this capacity is more limited than that for conjugate changes.