The hidden digit plates of Ishihara color blind test, that normal color vision observer don't see! Only individuals with color blindness could recognize the figure. The more severe color blindness, the more frequently read these plates.
Note: About half of the normal color vision subjects between 20 and 30 years of age read hidden-digit plates and hardly ever read by subjects over 50 or by young children. (Source: Procedures for Testing Color Vision: Report of Working Group 41., National Research Council (US) Committee on Vision: National Academies Press (US); 1981.) Not suitable for clinical diagnosis! You have to enter the number(s) for each plate you can see. If you don't see anything just click to the next button. There will be 4 plates.Click to the next button to start!
