The eye is easily deceived, and our faith in the reality of what we see is therefore precarious. For two millenniums we have been told so.
The purveyors of this doctrine disregard certain facts. The deception is possible only for a single eye at a fixed point of observation with a constricted field of view, for what I called aperture vision. This not genuine vision, not as conceived in this book. Only the eye considered as a fixed camera can be deceived. The actual binocular visual system cannot. (Gibson, 1979, p. 281)
Ok. So, grant that aperture vision is not genuine vision as Gibson conceives it. Concede, just for the sake of argument, that only the eye considered as a fixed camera can be deceived and that the actual binocular visual system cannot. Still, something is going on during episodes of so-called "aperture vision" and a scientist might well want to know what. So, why not have a scientific study of aperture vision along with a scientific study of "the actual binocular vision system"?
Just be sure, I guess we can add, not to simply assume that what one learns from aperture vision applies to "genuine vision". What's wrong with that?