Rapid afterimage

http://www.michaelbach.de…mage/index.html

One of the best visual illusions i’ve seen for a while. You should see a little green flash as each of the magenta dots blinks out. However, there isn’t actually any green in the animation at all. It just seems that way as you brain interpolates a negative after image. But now comes the cool bit.. keep your gaze fixed on the centre cross and the magenta blobs will start to fade away.. leaving only a green blob going round in a circle on a grey background.

I wonder what these monks would make of that?