Different humans vary widely in the tendency to move the head during saccadic shifts in gaze.
The reasons for this variation are unknown. We explored the possibility that variations in the ability to control eye movements at eccentric positions lead to variations in customary ocular motor range and, by extension, explain the variations in head-movement tendencies. We studied ten normal adults. We also determined the eye-only range, the orbital range within which the probability of a head movement accompanying a gaze shift was low. We then assessed variations in kinematics of several ocular motor behaviors as functions of eye eccentricity.