OCULAR TORSION POSITION AND THE PERCEPTION OF VISUAL ORIENTATION

Previous studies have shown that in patients with unilateral vestibula r deafferentation (UVD) there is a close relationship between the chan ge in ocular torsional position consequent on the UVD, and the visuall y perceived orientation of short dim lines in an otherwise darkened ro om (1). However that result may have been confounded because the UVD m ay have affected both ocular torsion and sensory information about hea d position re gravity which must be used in making the visual perceptu al judgement. Therefore we have sought a means of testing the relation ship between ocular torsional position and the visual perception of or ientation which was not confounded by the possible effect of changes i n perceived head position.