Both lines have the same lengh. The different angles make one line seem longer. This was first discovered by Franz Müller - Lyer in 1889. He was a German psychiatrist and sociologist. Derived :Müller - Lyer tickets Number of ratings : 31.
The two horizontal lines have the same length. You would think that the upper line is bigger. This is also called the railroad track illusion. Derived :Perspective distortion :: Schmidt Tea Number of ratings : 19.
Paradox Box Not really a book but a collection of visual playstuff in a box.
The Art of Optical Illusions Al Seckel has done a wonderful job of assembling this great collection of visual illusions. It is lavishly illustrated - mostly one illusion per page - with the majority in full color, allowing the reader a generous view of the eye-teasing pictures.
Little Giant Book of Optical Illusions With about 300 images, this book covers the most basic illusions you'll ever come across.
How to Really Fool Yourself This book features over 70 activities to fool all five senses. Each illusion is followed by a fascinating "Why You're Fooled" section that explains the science and history behind the "magic."
The Great Book of Optical Illusions A lot of the best illusions of this site in full color.