1) Vestibular ocular reflex Function: to keep the image of the world stationary on the retina when the head rotates. Try shaking your head while reading this sentence. The fact that you can do this means that your VOR is working; it is keeping your eye almost still in space. It does this by rotating the eyes opposite the direction of head motion. If the head tilts to the side (torsionally) the eye counterrolls, i.e. it moves out of Listing's plane. Thus the VOR does not obey Listing's law.

2) Pursuit Function: to keep the fovea on a small moving target, e.g. tracking a tennis ball. As in saccades, pointing the fovea at this moving ball is a 2D problem and Listing's law resolves which of many eye position to use.

3) Vergence Function: to align a near target on the fovea of each eye. Listing's law is violated during vergence between targets at different distances. An extension of Listing's law holds when vergence is at a constant distance.

Copyright © 1996 Tutis Vilis and Douglas Tweed
University of Western Ontario
London Ontario Canada
Updated October 28, 2005

Comments welcome. Email to tutis.vilis@schulich.uwo.ca