English: Highly schematized depiction of a birds eye view of a simplified human observer, represented by a head (labeled H), standing

at the intersection of four railroad tracks extending to infinity on a boundless plain. This observer has a limited field of view set by the eyes' bony orbits. Unseen parts of the scene are shaded. In the observers conscious perception of this scene, the actual geometry of the landsacape, in which parallel lines never meet, is remapped into a finite perceptual space bounded by the horizon (and the dome of the sky), at which parallel lines meet. It is represented by the large circle in the figure. To avoid cluttering the illustration, the perceived railroad tracks (depicted as heavy black lines inside the unshaded portion of the circle marking the observer's horizon), have been

truncated at their close approach to the observer, whereas the perceived reality is that they ”bend” around the observer's position, as it were (see Hatfield 2003). ”e” marks the visual ego-center, and the double arrow marks the visual field of view, or ”visual aperture.”