Keep staring at this picture for about 20 seconds and then look at a white surface (a wall or a big piece of paper). One of the very classic illusions. The best thing is ; the afterimage seems to be a sharper picture than the original.
I have no idea how this works, but Toronto's CN Tower is hidden somewhere in this picture. After looking at it carefully you may discover it, but this could take several tries.
Can you find the seven horses ? This image was used as the CD cover for the album "Horses & High Heels" by Marianne Faithfull.
An absolutely insane chalk drawing on the pavement. Batman an Robin are going to save a man from a burning building. Don't you get high anxiety when you look at this drawing ? Note the level of details : the real pavement is actually casting a "shadow" on the buildings below it.
In something as complicated as Camel fur, one can always recognize things which aren't really there. All kinds of things have been written about what can be seen in this Camel. But I found this shape and Manneken Pis (on the Grote Markt in Brussels) just too simiral to be coincidence ! Look at the front legs of the camel and you will see the little pissing boy. The national symbol of Belgium, how about that ?
This is one of the most amazing illusions. Keep staring at the blue dot in the middle of the picture. The blue dot will shrink slowly and then disappear completely ! This is due to the color receptors in your eyes getting tired.
Look at the cute little boy on the right side. He's shown in two different colors, right ? Now gaze at the left plus sign for 20 seconds, then look at the right plus sign. The image is looking normal now ! Ain't it incredible ? This phenomenon is called chromatic adaptation. Your eyes adjust themselves to the overload of colors. When you look at the right, your eyes are still filtering out the cyan and yellow. For a while.
A very good optical illusion : if you look at the picture carefully, after a few seconds, you can see a boat in the background.