Eye Rotations with Change of Accommodation

Abstract

THE apparatus, previously described¹, for studying eye movements of subjects in the sitting position, has been expanded so that side-to-side and up-and-down movements of the right eye can be recorded simultaneously. Rotations of this eye, occurring when accommodation is changed, have been studied with the apparatus. In these experiments, two fixation targets were used; both lay on the visual axis of the right eye when this eye was looking straight ahead. The farther target, which was viewed through a glass plate, was a bright pin-hole, angular diameter 1′, distant 5½ ft. from the subject. The nearer target was the mid-point between two virtual images, formed by reflexion at the front and rear surfaces of the glass plate, of another bright pin-hole. The virtual images were 2 ft. from the subject and the separation between them was 23′. Records were obtained for both horizontal and vertical separations of the virtual images. The subject fixated the far and near targets alternately; this cycle was repeated several times during a single recording, the frequency being at the subject's discretion. Records were obtained for both binocular and right-eye viewing of the targets.