Page 112 - Darwin's Dilemma: The Soul
P. 112
Darwin’s Dilemma: The Soul
The perception that we refer to as “distance” is a kind of
three-dimensional sensation. The factors we call perspective,
shade and movement awaken a sense of depth and distance in im-
ages. This depth perception, known as space perception in optical
science, is provided through highly complex systems. The simplest
way of describing the system is to state that the image reaching any
one eye is merely a two-dimensional one, with height and width
only. The dimensions of the images reaching the retina, and the fact
that both eyes see different images, give rise to the sensation of
depth and distance. The images falling onto our two eyes differ
slightly in terms of angle and illumination, and the brain then com-
bines these two images together into a single picture that gives a
sensation of depth and distance.
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