A selection from a set of illustrations by Nicholas Wade of famous men in the the history of perception research. The faces are often intentionally difficult to discern but may become clearer if the images are viewed from a greater distance. Thirty prints were exhibited at the 19th European Conference on Visual Perception.
Donders' see: Frans Cornelis Donders
Psychometric function: Gustav Theodor Fechner
Texture gradients: James Jerome Gibson