TONIC DEVIATIONS OF EYES PRODUCED BY MOVEMENTS OF HEAD

Abstract

It has long been known that movements of the head produce compensatory deviations of the eyes designed to preserve the orientationthe visual fields and to maintain visual fixation. Clinical and experimental investigations have revealed that these deviations depend on a complex series of reflexes, some of which are still imperfectly understood. It is with the analysis of these that this paper is concerned. Before these deviations are considered, however, it is necessary to orient the reader by a general discussion of ocular movements. The movements of the eyes are controlled by several neural mechmechasmnisms the cerebral cortex and neuraxis. These mechanisms send impulses to the nuclei of the third, fourthixth nerves, which in turn innervate the extraocularn the terminology of Meyer, there is a simple segmental apparatus, the third, fourth and sixth nerves and their association tracts, on which certain suprasegmental structures exert a cont-olling influence. The latter include the oculogyricthe frontal