Everyone likes a good optical illusion, but fewer understand them. Today we interview Katie Tregillus PhD about her research on color perception and adaptation. Katie takes us through the strange and complex world of color, from basic physiology up to conscious perception. How can different people looking at the same image 'see' totally different colors? How do colored lenses change our perception of the world of color? And what are some of the craziest visual illusions and perceptual...