Test Chart Books Features:
• 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.
• Consist of a number of colored plates.
• On each plate is printed a circle made of many different sized dots of slightly different colors, spread in a random manner.
• Within the dot pattern, and differentiated only by color, is a number.
• What, or even if, a number is visible indicates if and what form of color blindness the viewer has.
• The full test consists of thirty-eight plates, but the existence of a deficiency may be clear after fewer plates.
• The Ishihara Color charts are accepted by leading authorities worldwide as a simple and accurate test method.
• Color plates encased in specially designed album-type books for ease of handling.
• Detailed instructions included.