Rats fooled by Asahi optical illusion may shed light on evolution of the eye

An optical phantasm that performs with our notion of brightness additionally appears to work on rats, suggesting that the connection between notion and pupil measurement advanced early on in mammals.

The Asahi phantasm is made up of a collection of petal-like shapes surrounding a white centre. The petals are yellow near the centre, transitioning to black on the edges, and this gradient, mixed with the form of the petals, makes it appear as if the white centre is brighter than it truly is. …