Fig. 4.
Filled spaces look larger than empty ones because the eye unconsciously stops to look over the different parts of the filled area, and we base our estimate upon the extent of the eye movements necessary to take in the whole field. Thus
the filled square in Figure 5 looks larger than the empty one, though they are of equal size.
Fig. 5.
White objects appear much larger than black ones. A white square looks larger than a black one. It is said that cattle buyers who are sometimes compelled to guess at the weight of animals have learned to discount their estimate on white animals and increase it on black
ones to make allowances for the optical illusion.
THIS MAN AND THIS BOY ARE OF EQUAL HEIGHT, BUT ASSOCIATION OF IDEAS MAKES THE MAN LOOK MUCH THE LARGER
Use of Illusions in Business