Accepted by leading authorities as a simple and accurate method for discovering congenital color blindness and red-green blindness each in two forms complete and incomplete * Includes four special plates for tests to determine the kind and degree of defect in color vision * Makes use of the peculiarity that in red-green blindness blue and yellow appear remarkably bright compared with red and green * Color plates encased in specially designed album-type books for ease of handling * Detailed instructions included