Commentary

Abstract

The authors are to be commended for this interesting study. Physical therapists long have overlooked the use of different types of eye movements in rehabilitation, with the possible exception of the vestibulo-ocular reflex (VOR). The role of all eye movements is to either bring or maintain the target image on the fovea of the retina. Saccadic eye movements are used to shift between different targets. If the target is stationary and the head is moving, then an interaction between the VOR and the optokinetic response (OKN) stabilizes the image on the retina. With moving targets, however, smooth pursuit eye movements (SPEMs) must be used to stabilize the image on the fovea. The perception of self-motion during SPEMs has been shown to be produced only when a sufficiently large target is moving in one direction around the individual.