- color perception test equipment
Equipment for testing an observer's color vision. Some tests require the identification or ordering of colored samples. The commercially available examples include: the Ishihara plates, on which observers with normal color vision can see patterns that color-deficient observers cannot; and the Farnsworth-Munsell test, in which samples must be arranged in order of a procession of hue. Other tests, such as the Nagel anomaloscope, require the observer to make a metameric match to yellow light using a mixture of red and green; observers with normal and color-deficient vision obtain different results. See also eye test apparatus.