Colour Blindness Test Book  (Hardcover, Dr. Shinobu Ishihara)

The test consists of a number of colored plates, called Ishihara plates, each of which contains a circle of dots appearing randomized in color and size. Within the pattern are dots which form a number or shape clearly visible to those with normal color vision, and invisible, or difficult to see, to those with a red-green color vision defect, or the other way around. The full test consists of 38 plates, but the existence of a deficiency is usually clear after a few plates. individuals with color vision defect should see a different figure from individuals with normal color vision. Makes use of the peculiarity that in red-green blindness, blue and yellow appear remarkably bright compared with red and green Diagnostic plates: intended to determine the type of color vision defect Ishihara Test Chart Books for Color Deficiency 38 Plates with usar manual