OPTICAL ILLUSIONS

An optical illusion is an illusion of our sight sense, that makes us perceive the reality wrongly. This illusions are used in some arts, like cinema or paintings. In arts, they're called trompe-l'oeils:

There are many types of optical illusions. Some of them are:

- Stereoscopic images: if you cross your eyes lightly, you can mix two similar images to create a 3-dimensions one.

- Autostereogram: if you cross your eyes standing 30 cm in front of these images, you'll see as if it had 3-dimensions relief. In the first one you'll see a heart, in the second one, a shark.

- Motion illusions: if you move your head towards and backwards the picture, looking at the point of the centre, you'll see the two circles move.

- Other effects: In the first case, all the lines are pallalel, even though they don't seem to be. In the second image, the two circles are the same size.