Even when the retinal image
remains the same, the camera
theory cannot explain the way
objects appear to us. For
example, the moon appears to
be larger at the horizon than
when it is elevated in the sky,
yet the size of its retinal image
remains essentially the same.
Similarly, the image to the left
can be seen either as a vase or
as two profiles, although the
image on the retina remains
the same. If perception is like
picture-taking, how can we
explain the fact that a single
picture can yield two or more
distinct perceptions?