Grid Illusion

source : http://en.wikipedia.org/wiki/Grid_illusion

The picture above in the form of boxes and white lines. but look carefully, you'll see a black dot moving when you see it and until now I have not been able to make a silent black dot moving it. Perhaps the point was a ninja so hard to catch or something fast, but I do not care and I wanted just to make it stop moving black dots that I can count them.

 
If I read on wikipedia, the picture is named Grid Illusion, "... a grid illusion is any kind of grid that deceives a person's vision. The two most common types of grid illusions are the Hermann grid illusion and the scintillating grid illusion .. . "and many explanations (please click here).

I got a riddle, what you try to see but you can never see without help mirror? If you know, I'll give you lighters.

*so, what do you think about that picture?
comment on with your language ...