Popis: |
To the Editor: —The article by Dr. Joseph I. Pascal "Parallactic Angle in Binocular Depth Perception" (Arch. Ophth. 28: 258 [Aug.] 1942) is interesting because it shows renewed attention to problems relating to military service. Perception of depth is an important factor, especially in so far as flying is concerned. The explanation given in the article, however, is not an explanation of the parallactic angle. It is a complicated explanation of the angle of convergence, which is another of the factors involved in depth perception. This explanation when reduced to its simplest form resolves itself into the fact that there is a different angle of convergence between the two eyes when first one object is fixed by binocular vision and then another, which is either nearer or farther away. This is the well known factor of convergence. The ingenious explanation of dextroversion and levoversion with convergence and divergence stimuli only |