This image documents an earlier version of the Symbiont, which utilized a tool which is currently being developed to perfection. This is the eye-tracking device. The participant's head must be immobilized (by a brace in this case) in order for a lens to follow the precise movements of the eye. In this image, the eye of the subject is visible on the screen and the nipple has not yet been inserted into the mouth. In the version of the eye-tracking system that is currently in process, the movements of the subjects eye will trace a pattern across the screens of the Symbiont, gradually uncovering another image underneath. In another version of the Symbiont, the eye controlled the selection and zooming of the image.