 This theoretical astigmatism cannot explain El Greco's style though, as he would have seen his canvases distorted in the same way, and painting onto them would have cancelled out any distortion.It is believed the term originated with Irvin Rock, in his 1966 book, "The Nature of Perceptual Adaptation".When explored in experiment — by having subjects wear distorting lenses — it seems likely that El Greco would have completely adapted to seeing a distorted world, and this could not have been an explanation.