Hi @biwash,

I love these little puzzles and mind-trips. The optical illusion here, of course, is that the dark background makes the white dots appear to be a shifting pattern of black dots. The problem here: I found the black dot.

The Black dot is circled in red with the black arrow pointing to it.

You can't fool me!

Ok, so in all seriousness I like these puzzles, so I gave you a 100% upvote; however, it comes with a Challenge. The Challenge: research the phenomena and background of these types of tests and provide us with more information regarding these types of tests. Then, afterwards, come back to this post, find the row where you would upvote your post, and click 'Edit' to add that information.

Then, afterwards, respond to this comment to let me know when that is done.

Will you accept the challenge?