From the "Depth Spinner" to the "Cafe Wall Illusion," the Exploratorium has collected menagerie of thought-provoking and visually intriguing optical illusions. These particular illusions were picked out by staff members and represent the best of the best. First-time visitors simply must start with the "Fading Dot." This exercise in visual acuity will show users that the eye is constantly receiving...
Professor John Daugman of the University of Cambridge Computer Laboratory is the author of this paper on iris recognition. It examines the characteristics of the human iris from a statistical perspective in order to estimate the requirements for accurate identification. Many complex issues of pattern recognition are addressed, such as the problems of isolating the iris and maintaining accuracy...