Ishihara Test Chart Books, for Color Deficiency by GF Health

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 Makes use of the peculiarity that in red-green blindness, blue and yellow appear remarkably bright compared with red and green On each plate is printed a circle made of many different sized dots of slightly different colors, spread in a random manner What, or even if, a number is visible indicates if and what form of color blindness the viewer has Color plates encased in specially designed album-type books for ease of handling