Letter from the Editor; 105 Mind-Bending Illusions; Special Editions; by Mariette DiChristina; 1 Page(s)

"The camera does not lie," the saying goes. And we tend to think of our eyes and our other sensory organs as video equipment, faithfully recording all the details of our busy lives. As you will learn from the articles on illusions collected in this special issue, however, we see with our brains, not with our eyes. And our brains make instant value judgments about the jumble of incoming sensory information, depending on what is important at that moment to us, to create a sensible narrative of the world around us.

Rather than pondering every bit of light that enters our orbs, the brain quickly jumps to conclusions, based on millions of years of evolution. Humans are intensely visual creatures, and we have developed an incredible apparatus for detecting things that are critical to our survival, such as predators, prey and mates. For instance, we can instantly mentally assemble several tiny patches of orange with stripes peeking through dense foliage: "tiger!" As we glance around a room, the image bounces on the retina (the light-receiving tissue at the back of the eye) as various areas of the scene excite different groups of cells. Yet the world appears stable to us, the view a smooth pan across our surroundings. The brain even fills in missing bits of picture in the eye's blind spot, where the optic nerve pierces the retina.