Fig. 5. Comparison of eye speeds at stimulus speeds of 5 ° s^-1 and 15 ° s^-1 during normal optokinesis (white square; temporo-nasal, TN, direction) and split optokinesis, during which each eye responds to a different stimulus speed (black square; both eyes are stimulated in TN direction). Pipefish (left) and sandlances (right) show the appropriate eye speed to the respective stimulus speeds, suggesting that the slow-phase response in each eye is independent of that of the other eye.