Hans Gertz Revisited: The Different Effects of Invisibility and Darkness on Pursuit Eye Movements

Abstract
Subjects were required to track their self-moved hands with smooth eye movements in total darkness. The effect of holding transparent and opaque screens between the eyes and the hand upon pursuit eye movements was examined. Opaque screens produced a significant decrement in pursuit when the eye was moving in a direction in which it was generally less efficient at making smooth eye movements.