What happens to eye when looking up and down during convergence?

When Listing's plane rotates temporally by as much as the eyes converge, the eyes
  1. incyclorotate when looking up and
  2. excyclorotate when looking down.

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