In this lecture, part of the celebration event for the tenth anniversary of the Andrew Wiles Building, home to Oxford Mathematics, Andrew himself traces the background to the one of the most famous series of conjectures in modern mathematics, starting in the sixteenth century with a poem.
Oxford Mathematics Public Lectures: The Mathematics of Visual Illusions - Ian Stewart
Puzzling things happen in human perception when ambiguous or incomplete information is presented to the eyes. For example, illusions, or multistable figures occur when a single image can be perceived in several ways.