User:Ruotailfoglio/Sarcone elliptical illusion

Sarcone elliptical illusion (or Sarcone's ellipses) is an optical illusion of relative size perception described by the Italian visual researcher Gianni A. Sarcone in 1997 (though it had been popularized later in his 2002 book 'Dazzling Optical Illusions'.

In the best-known version of the illusion, two ellipses of different size crossed by a straight line are placed near to each other. The line within the large ellipse is generally in red, while the line within the small ellipse is blue. By effect of assimilation, the diagonal red line within the large ellipse seems subjectively longer, but in fact the blue line is objectively the longest of both lines.

The Sarcone elliptical illusion is related to both Ebbinghaus and Sander illusions.