The café wall optical illusion was first described by Richard Gregory, professor of neuropsychology at the University of Bristol, in 1979. When alternating columns of dark and light tiles are placed ...

It seems obvious that the lines are slanted, but in reality they are perfectly parallel. A look at the black-and-white diamonds at each intersection of the lines shows that they are perfectly straight ...

Do the horizontal bars on the image below look like they're bending or are at an angle? If you think they are - look closely again. The lines are actually straight and in parallel rows, and the ...