As soon as this optical illusion emerged on Reddit and Imgur, it immediately aroused a storm of comments, as what was universally thought as two ordinary pictures taken from different angles or heights appears to be one and same image. For the rest, praise you brain, as it conducts a fantastic range of neuron-based operations, most subconsciously though.
Neither photo was, notably, mirrored, twisted, or edited in any way. To prove the point, one Reddit user even labeled the pictures and put one atop the other one.
Another Reddit user, All-Cal weighed in the debate with the following theory:
"It's because the two streets come together at the bottom of the pictures. Your brain tries to perceive this as one image with a fork in the road and therefore the street in the picture on the left must be at a different angle than the picture on the right."
Separately, the street pictures illusion could be in a way compared with another mind-bending one – the black and white tile picture first detailed by neuropsychologist Richard Gregory.
The Cafe Wall Illusion by Dr Richard Gregory pic.twitter.com/MGufyNIQo6— siyingzz (@yingzz4) 24 мая 2015 г.
In the picture, although the horizontal lines are most certainly straight and parallel to one another, the tiles are actually askew.
"Diagonal lines are perceived because of the way neurons in the brain interact," The Daily Mail explained, adding that different types of neurons are responsible for the perception of dark and light colors, the lines being at times dimmed or brightened in the retina.
In the first illusion, diagonal lines may also have done the trick.