COLOUR BLINDNESS TEST BOOK: Ishahara (65x images)

COLOUR BLINDNESS TEST BOOK: Ishahara, 65x Images

• This Colour Blindness Test Book is a good example of a colour perception test for ‘red-green’ colour deficiencies.
• The test consists of 65x images in a book 210mm long x 145mm high, Chinese print.
• Each plate contains a circle of dots of random size and colour.
• Within the circle of dots a number or shape is clearly visible to those with normal colour vision, and invisible, or difficult to see by those with a red-green defect.
  (Note: Photo for reference. Product may vary.)

(Wikipedia excerpt: .."...The Ishihara test is a color vision test for detection of red–green color deficiencies. It was named after its designer, Shinobu Ishihara, a professor at the University of Tokyo, who first published his tests in 1917.[2] The test consists of a number of Ishihara plates, which are a type of pseudoisochromatic plate. Each plate depicts a solid circle of colored dots appearing randomized in color and size.[3] 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.

Other plates are intentionally designed to reveal numbers only to those with a red–green color vision deficiency, and be invisible to those with normal red–green color vision. The full test consists of 38 plates, but the existence of a severe deficiency is usually apparent after only a few plates. There are also Ishihara tests consisting of 10, 14 or 24 test plates, and plates in some versions ask the viewer to trace a line rather than read a number.[4]...")