Features: Professional test book, which simple and accurate methods for find congenital color blindness and red-green blindness. It includes 38 special plates for tests to determine the kind and degree of defects in color-vision. Individuals with color-vision defects should see un-same figure from individuals with normal color-vision. Color blindness test book made of high-quality paper, with good touches feelings, which can be used for long periods. Color plates encase in specially designed album-type books for ease of handling. Specifications: Material: Paper Package Includes: 1pc Color Blindness/ Color Deficiency Test Book note: 1: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2: Due to the difference between different monitors, the picture may not reflect the actual color of the item.