Stereograms are made via a very similar procedure to that used in cartography in that the points that are closer to the viewer are lighter, while the ones further away are darker. But this knowledge is constantly being changed by the existing light sources. In our everyday life, our eyes merely function as sense organs, and our brain - the only organ responsible for interpretation - as a receptive organ. We do not project the world any longer; rather, it is the world which is projected on us.