Tricking the brain

Our visual system does not simply measure the light coming from a surface, it interprets in the context of its surroundings

Many years ago I published a puzzle — an optical illusion. It was for a chess news page, so I took the original image that was making the rounds and inserted chess pieces. This is what I presented my readers:

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  • Which square is lighter, the knight square in the middle or the knight square at the top?
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Bonus video

Addendum (7 April 2017)

This is probably the best colour illusion I have encountered:

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Written by

Frederic Alois Friedel, born in 1945, science journalist, co-founder of ChessBase, studied Philosophy and Linguistics at the University of Hamburg and Oxford.

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