If you did not know, we have our retinas inverted in the sense that the light that enters our eyes has to pass through many layers of nerves, blood vessels and all the wiring before reaching the photo detectors themselves. Even more troublesome, is the fact that it seems that the images are completely distorted and blurred when they arrive the photo-detectors. However we surely know we can see very well. Why did we evolve this feature? and how do we really see? Some of the answers can be found in this absolutely amazing paper
V. D. Svet and A. M. Khazen, About the formation of an image in the inverted retina of the eye, Biophysics, Volume 54, Number 2 / April, 2009, pp 193-203
The key point of this article is that we process the images in blocks. This means that we collect a sequence of images, which we process together in order to improve the signal/noise ratio.
There is a recent independent article here, suggesting that we actually see images in discrete sequences, which is completely consistent with Svet's theory.
I met Dr Svet in Windsor, Canada, where he gave a few seminars about topics concerning sonar imaging and detection. I expect to write more entries in my blog about other topics of his research.