What does it mean to be “visually aware”? One thing, due to Franz Brentano (1838-1917), is that all awareness is awareness of something. One says that awareness is intentional. This does not mean that the something exists otherwise than in awareness. For instance, you are visually aware in your dreams, when you hallucinate a golden mountain, remember previous visual awareness, or have pre-visions. However, the case that you are visually aware of the scene in front of you is fairly generic.
The mainstream account of what happens in such a generic case is this: the scene in front of you really exists (as a physical object) even in the absence of awareness. Moreover, it causes your awareness. In this (currently dominant) view the awareness is a visual representation of the scene in front of you. To the degree that this representation happens to be isomorphic with the scene in front of you the awareness is veridical. The goal of visual awareness is to present you with veridical representations. Biological evolution optimizes veridicality, because veridicality implies fitness. Human visual awareness is generally close to veridical. Animals (perhaps with exception of the higher primates) do not approach this level, as shown by ethological studies.
JUST FOR THE RECORD these silly and incoherent notions are not something I ascribe to!
But it neatly sums up the mainstream view of the matter as I read it.
The mainstream account is incoherent, and may actually be regarded as unscientific. Notice that it implies an externalist and objectivist God’s Eye view (the scene really exists and physics tells how), that it evidently misinterprets evolution (for fitness does not imply veridicality at all), and that it is embarrassing in its anthropocentricity. All this should appear to you as in the worst of taste if you call yourself a scientist. [p. 2-3]
I hold similar views, last time expressed in the post Ideology in the vision theater (but not with the same mastery as Koenderink, of course). Recall that “computing with space“, which is the main theme of this blog/open notebook, is about rigorously understanding (and maybe using) the “computation” done by the visual brain with the purpose to understand what space IS. This is formulated in arXiv:1011.4485 as the “Plato’s hypothesis”:
(A) reality emerges from a more primitive, non-geometrical, reality in the same way as(B) the brain construct (understands, simulates, transforms, encodes or decodes) the image of reality, starting from intensive properties (like a bunch of spiking signals sent by receptors in the retina), without any use of extensive (i.e. spatial or geometric) properties.