Ishihara's Design Charts for Colour Deficiency of Unlettered Persons

These series of plates provide a quick and accurate assessment of congenital, the most common form, of colour blindness. They distinguish between total colour blindness and strong and mild forms of both protan and deutan deficiency. A brief guide to use and interpretation is provided. In this 10 plate edition simple geometric shapes takes the place of numerals for use with infants and unlettered people.