this is the perspective projection that we have with our eyes: spherical projection. detail here: http://www.treeshark.com/treeblog/?p=301 http://www.treeshark.

this is the perspective projection that we have with our eyes: spherical projection. detail here: http://www.treeshark.com/treeblog/?p=301 http://www.treeshark.com/treeblog/?p=301 At any given moment we're only looking at a very small slice of that larger spherical panorama. Our brains are constantly constructing a coherent 3d model, with the help of various schematic constraints, such as expectations about straight lines being straight. We perceive straight lines. but that's not what we see. But the curvature is usually so slight that it is very difficult to see.