GOING GREEN The center square of the disk on the left (marked with a dot) appears green, while the center square of the disk on the right appears orange. The two are identical in hue. The fact that we can perceive colors consistently at all is astonishing, considering that our brains must take into account not only the color reflected from the object but also the color of the illumination and the context. Each parameter influences the frequency of the light as it reaches the eye, yet we still see blue as blue whether we’re in brilliant sunshine, under fluorescent light, or looking through water. We are capable of distinguishing roughly 1 million colors.
Beau Lotto theorizes that the reason humans are vulnerable to optical illusions is that we are not really responding to the physical properties of the object we are looking at. Rather, we “see” things based on what other things similar to the current image have typically turned out to be in the past. The implication: The visual cortex is evolutionarily adapted to the sensory information it receives, not to the world beyond. Such forced interpretations allow us to recognize important objects (fruit in a tree, a tiger in the grass) quickly, but at the cost of total accuracy. Basically, we do not see the world the way it really is because our brains will not let us.