A new set of illusions: the dynamic luminance-gradient illusion and the breathing light illusion

A novel set of illusions that break brightness constancy and size constancy at the same time is reported. The illusions occur when observers move towards or away from these patterns. Many variations of these phenomena and a possible explanation are discussed. We introduce here a new set of illusions that show illusory variances in brightness and also in size of the stimuli. During the 2006 meeting of the Vision Sciences Society (VSS), Alan Stubbs showed his illusions, created in Maine, USA, in the 'Best Visual Illusion of the Year Contest', hosted by the Neural Correlate Society, while Simone Gori showed his illusions, created in Germany, during the VSS 'Demo Night'. Although the patterns were different and Stubbs stressed more the illusory variance in luminance while Gori stressed more the illusory variance of the size, the two phenomena were actually very related to each other and they also have common origins. After this meeting the two authors decided to work on this new set of illusions together. This article is the result of their efforts.