102 Visual Phenomena & Visual Illusions – website of Michael Bach, a German professor of ophthalmology. Each illusion or phenomenon is explained, includes references, and an interactive way to convince yourself of what’s really happening. Absorbing and fascinating, especially for anyone involved with design, color, signage and wayfinding. Shown here is “Rotating Snake” Illusion, or try Shaded Diamonds or Colour mixtures. There are sections on Motion & Time, Luminance & Contrast, Colour (or color), Geometric- & Angle Illusions, Space, 3D & Size Constancy, Cognitive- / Gestalt Effects, and Specialties with faces.