Forget the 'dress’ illusion, there’s a new trick that can make you see black and white as green and red for up to three and a half months.
The McCollogh effect was discovered by an American psychologist in Canada in 1965.
To make the trick work you have to stare at images of vertical and horizontal lines so that you eventually start to see black and white as green and red.
The trick, which comes with a warning, as the effects can last over three months, is explained by Tom Scott on his YouTube channel, Things You Might Not Know.
To perform the trick you need to look at the test grid of black and white lines and confirm they do indeed look black and white.
Then you look stare alternately at the square containing red and black stripes and the one with green and black stripes, below, for up to three minutes.
Then you look back at the black and white lines once more.
At this point, you should be able to make out that the top right and bottom left vertical stripes of the black and white grid are a little pink, whilst the top left and bottom right horizontal stripes should appear slightly green.
But that is not the end of it, as with this particular illusion the effects can last for quite some time - depending on how long you practice the exercise for.
It is recommended that you do not carry it out for longer than 15 minutes.
The exact reason the trick works, is not completely understood, however, but the exercise bears some similarity to the infamous blue/black or white/gold dress that caused such a stir back in February.
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