This optical illusion in knows as Hermann grid illusion reported by Ludimar Hermann in 1870.
During 1994, E. Lingelbach has discovered that if white discs are put on the intersections of orthogonal gray bars on a black background. Dark dots seem to appear and disappear rapidly at random intersections.
We, at SmartImage, stepped one more step and made a cool game where some of those discs are appearing really inside the grid.
You have to find the real discs appearing around the grid.
On the beginning, it is very easy, since we made the discs to highly contrast in order to help you find them.
In each level the contrast is soften, and the task of finding the real disks become more and more difficult.
To play this game, the following rules apply:
When you see a real blink, you have around two seconds to touch it and to get one points.
If you touch a wrong spot, or touch the right spot to late, you will lose 2 point.
If you login to Game Center, your high scores will be save them for your reference, or to compete with other players.
Good luck and enjoy.