Or does it ? The eye-brain combination is fantastically complex and capable and one that we mostly can (thankfully) take for granted. Dynamic Range is one such area - the range of light in which detail can be accurately perceived - reading a dim kindle on a sunny beach, for example. (I wish). The perceived 'dynamic range' of the eye is much wider than conventional cameras - we can seamlessly make sense of very dark scenes that are just next to very bright scenes. In photographic terms the range can be '24 stops'. Good cameras might achieve 13 stops. The science seems complex, and of course there is a lot of info out there as to how the brain (and eye) achieves this. I suppose the need to survive in the dark and be able to hunt in the day pushed this evolution along. I wonder.
Another example of perception vs reality is how we correct for vertical distortions of, say, building verticals, due to our eyes having a very wide angle. One value for this could be a focal length of approx 22mm (you might imagine, it's not straightforward making this statement). That's wide enough to distort verticals, and what we know to be parallel lines appear to converge. Architects use this perception to manipulate our awareness of a building - the colonnades of the classical Parthenon is an interesting example of this. But our brain knows they are vertical, from learned experience, and adjusts accordingly.
Here's an example - the Zappeion in Athens. The first photo is my original - 16mm (so a little shorter focal length equivalent than the eye's) - 1/200th sec, f/11, ISO 200, full frame Canon.
Look at the converging verticals.
Even as you're looking, the brain is interpreting the column as vertical and correcting for you, although not as 'efficiently' as it does in real life. At the scene it's very difficult to 'see' the converging verticals because the brain is automatically correcting for you - and the override technique is buried deep in evolution. I can't imagine an optical scientist, an evolutionist, or an anthropologist is going to be very impressed with my simplistic understanding of all this!
Now here's my corrected version, I've corrected the vertical columns to vertical (and also photoshopped out the gantry. And tidied up the exposure and removed some haze too - thanks to software called DXO Optics Pro).
It's quite a remarkable difference isn't it ?
(Various sources of info about the eye, including :