Someone once told me that the world is upside down but our minds correct this and we see the world right-side up. Sky side up. This is not true. The world is right-side up and our eyeballs are curved like a crystal ball that focuses light onto the retina. The resulting image is a projection of the world-oriented upside down because of curvature. The brain does not care that the image is physically disjointed from reality because it can represent the data in almost any orientation. It just so happens that the most adaptive way to represent this data is in a way that doesn't disorient us and lead to injuries; right side up.