Two historical strands in studying visual direction

How we see the direction of an object has been discussed since the time of Aristotle. Despite this early beginning, there are two strands of conflicting ideas on visual direction that remain to this day. The first strand is based on observation or phenomenology and generated the idea that the midpoint between the two eyes is the reference point for visual direction. The second strand is related to geometry or optics and generated the idea that the reference point is an eye. To discuss this issue, we focus on visual directions of stimuli that stimulate both foveas. The observational strand has provided ample evidence to support their idea that the midpoint between the eyes is the reference point, yet the idea that the reference point resides in an eye still persists. We examine how the two strands have evolved since antiquity and speculate as to why the second strand persists. We then offer an intuitive explanation for the idea generated by the first strand in order to counter the persistence of the idea generated by the second.