The test consists of a number of colored plates, called Ishihara test 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, 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 User Manual