It’s amazing we perceive as clearly as we do, given the situations that confuse us and the tricks we can think up to confuse ourselves.
Our senses are remarkable. They have evolved to enable us to accurately perceive a huge variety of things in very different conditions. However, occasionally our senses let us down, and we fail to perceive the world accurately. The resulting illusions give us great insight into how our senses work, and how they usually manage to do so astonishingly well.
Illusions intrigue us. It is fascinating to observe our senses getting things wrong, and to continue to do so, even when we know the nature of the illusion. And it is intriguing to ponder what we aware of, when we seem to be aware of something that isn’t there in the world in front of us.
The Illusions Index is a fully searchable curated collection of illusions brought to you by the Centre for the Study of Perceptual Experience. It will be regularly updated with new illusions, so check back often. We hope that you enjoy discovering the illusions and the nature of your own perception! More.
Example: Grey strawberries:

See also: How the zebra got its stripes, maybe