Dimension and orientation: connected vessels of perceptual evaluation of space

Perceived world differs in many aspects from physical world. After introduction summarising knowledge concerning depth perception, authors describe psychophysical experiment in which they tested the accuracy and reliability of perceptual judgements of size and direction. The inherent interconnection in the perception of both dimensions defining the space - the size and the direction - is one of the findings implied by the results of the experiment. Conditions that are suitable for the reliable perception of the size of stimulus are on the other hand not suitable for the reliable perception of stimulus direction, and vice versa. In the last part of the study, the validity of mathematical model supposing direct correspondence between retinal image and percept is tested for the data obtained in the experiment.