Boynton illusion


Upper panel of Figure 3.11.35 from Stockman, A., & Brainard, D. H. (2009). Color vision mechanisms. In M. Bass, C. DeCusatis, J. Enoch, V. Lakshminarayanan, G. Li, C. Macdonald, V. Mahajan & E. van Stryland (Eds.), The Optical Society of America Handbook of Optics, 3rd edition, Volume III: Vision and Vision Optics. New York: McGraw Hill.


Boynton illusion. In the upper picture, a star-shaped black outline is superimposed on a circular yellow area, while in the lower picture a circular black outline is superimposed on a star-shaped yellow area. If you move away from the picture, the yellow areas appear to fill the black outlines. These are variations of an illusion attributed to Robert M. Boynton by Peter Kaiser, see: