"I immediately thought it was a trick question and the circles would be the letter O in the text or something like that. But neat illusion!" one person raved on a Reddit thread. Another commented ...

There is a mathematical side to optical illusions ... in 3D. Another area of Sugihara’s research is “ambiguous objects”, which includes the groundbreaking study of a square-circle visual ...

The white circles appear to form a circular ... If you’re a really big fan of optical illusions, how about one that you can 3D print? That’s exactly what Struck Duck did with this mindbender.

However, if you keep looking at the black and white image, your perception may suddenly switch to 16 circles. If the illusion hasn't happened for you yet, try focussing on the space in between the ...

but Patrick Hughes' mind-boggling 3D art takes the concept to a whole other level. Hughes uses a style he created called "reverspective," painting uncanny optical illusions of a rooms with an ...