Same Colour Or Different? Grey Block Optical Illusion Confuses People Online

The internet has blown our minds time and again by dishing out various optical illusion tricks, first with coloured spheres then by the hand swap trick. Various makeup artists have also succeeded in baffling us by creating illusional masterpieces using just makeup. This time, a couple of coloured blocks are making us scratch our heads.

TV show host Kate Garraway recently shared an image on Instagram that has sparked discussion online. The 52-year-old posted a picture of two grey blocks piled on top of one another. But, both the blocks appear to be of totally different shades of grey when seen from a distance. The block on top appears to be of a darker shade, while the second one looks lighter, reported NDTV.

View this post on Instagram

This caused a right stir in our house tonight…

A post shared by Kate Garraway (@kategarraway) on

However, the image claims that if a finger is placed between the two blocks, they will surprisingly appear to be of the same shade. Obviously, people tried the trick and were impressed by the sorcery.

They took to Twitter to express their ‘disbelief.’

As reported by Mail Online, the image shared by Kate is called the ‘Cornsweet illusion’. It was first documented by experimental psychologist Tom Cornsweet (best known for his work in visual perception) in the 1960s. His theory noted that ‘humans perceive colour and shade of 3D images in a certain way depending on how the items are lit and where shadows fall.’

Probably, that’s the reason why our brain is tricked into believing that the two blocks appear to be of different shades when seen from a distance and looks similar in the absence of light. What do you think of this trick? Tell us.

📣 Storypick is now on Telegram! Click here to join our channel (@storypick) and never miss another great story.