Above you see a dot surrounded by a grey blur. Focus your attention on the dot. Come closer to the screen. What happens to the blur? Keep looking, you will be surprised.

Here is another new and famous illusion [discovered by E. Lingelbach in 1994]. Note the grid of grey bars with white dots at their intersection. Without focussing your eyes on any specific part of the pattern, gaze at it. Notice that random white dots suddenly become black! This recent illusion (1993-4) has a complex history. Illusion websites usually confuse it with the unrelated Hermann Grid Illusion. A primitive version was in fact discovered by J. R. Bergen and the current version was found by Elke Lingelbach.

On Internet web pages this Lingelbach illusion is almost always confused with the 19th-Century Hermann Grid illusion. In the Hermann illusion, a grid of white lines on black shows grey smudges at the intersections of the white lines... like this:

However, if you place dots at the intersections of the lines, you have an illusion which is a kind of combination of the Lingelbach and Hermann grids!

Want more? How about a combination of illusions on this page? Fix your attention on the mandala-like pattern below and let your eyes relax. Shortly you will see white circles expanding outward from the center of the pattern! What do you think is the origin of this illusion? You will also see the black petal-like outer pattern show shades of red and green!