Ishihara Colour Deficiency Test – 24 plates
Ishihara Colour Deficiency Test with 38 Plates. Colour deficiency test with 38 plates. Tests for protan & deutan defects. Patients must identify numbers or patterns formed in a matrix of small coloured dots varying in colour & intensity (pseudo-isochromatic plates). Ideal for commercial/industrial colour screening.
The test consists of a number of colored plates, called Ishihara vision 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 Ishihara test consists of 38 plates, but the existence of a deficiency is usually clear after a few plates. There is also a test consisting of 14 or 38 plates.
The 24 plates is the most popular version. The 24-plate version (Abridged) is used principally at factories and offices of transportation and other concered places of the
purpose of conducting usual sample survery for color deficiency in a short space of time when hiring new employees.