[On the metric of visual space]

The major aim of this overview was the visual perception of egocentric (distance from an observer to a target) and exocentric distance (distance between two targets). We considered different issues concerning the relationship between perceived distance and physical distance, giving special attention to the theories, to the cues regarding distance, how perceived distances are measured, and the types of visual environments where the measuring of distances occurred. We concluded that the perceived distance does not reflect a simple transformation of its physical counterpart; rather, the mapping between perceived distance and physical distance depends substantially on the type of visual environments where distances are measured, and, on the cue combination available in these environments.