The Ishihara Colour Deficiency Test is ideal for commercial/ industrial colour screening for protan and dutan defects.
Patients must identify numbers or patterns formed in a matrix of small coloured dots varying in colour and intensity (pseudo-ischromatic plates).
The third type is the 14-plate(Concise)edition. On the average, charts of highest accuracy were selected from the 38 plate(Complete) Edition to conduct minimum examinations of color deficiency.