How to check color blindness

The following are detailed methods of examination: 1. False homochromatism In the same color map, there are both patterns or numbers composed of spots of the same brightness and different colors, as well as patterns or numbers composed of spots of the same color and different brightness. In natural light, take 0.5 meters distance, should be recognized within 5 seconds graphics or numbers. Normal people to distinguish by color, color blind can only judge by light and shade. 2, hue arrangement method In fixed lighting conditions, the patient will be a number of colored chess pieces in turn with the previous chess piece color closest to the arrangement of the first chess piece behind. FM-100 color test and DY 5 color test are commonly used. According to the order of normal or not to judge whether there is color vision disorder and its nature and degree. 3, color vision mirror using red and green light properly mixed to form yellow light principle. Subjects according to the requirements of the proportion of red and green light. According to the proportion of allocation to determine whether there is color vision disorders, as well as the nature and degree of color vision disorders.