Beau Lotto, of Lottolab, a combination art studio and science lab, has a talk on TED, a conference started in 1984 to bring together bright lights from the disciplines of Technology, Entertainment and Design.
These talks are almost always informative, entertaining and brain-ticklingly thought provoking. Some are on art (see my post on The Face of Leonardo?).
In this particular talk, Lotto utilizes several familiar but striking optical illusions (see my previous posts on some of them here and here), plus a few others, but goes beyond the usual concerns of the mechanics of vision into the questions of why we see as we do, why these particular illusions work, and how the way we see functions in our adaptation to the world.
Much of the talk is about the nature of color, and in particular about a point that I often mention as perhaps the single most important thing I have ever learned about color, color mixing and color perception — that context is everything.