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Grafco Ishihara Test Chart Book for Color Deficiency
The Ishihara color test is a test for color blindness. It was named after its creator, Dr. Shinobu Ishihara, who was a professor at the University of Tokyo, and first published his tests in 1917. It uses the peculiarity that in red-green blindness, blue and yellow appear extremely bright compared to red and green. The test consists of a number of colored plates, on each plate is printed a circle made up of many dots of varying sizes and slightly different colors, spread in a random manner. Inside that dot pattern, and separated only by color, is a number. What, or even if, that number is visible indicates what form of color blindness the viewer has, if any at all. The full test consists of 38 plates, but a deficiency is usually detectable after fewer plates. The Ishihara Color Charts are widely accepted by leading authorities worldwide as a simple and accurate test method.
- Accepted by leading authorities as a simple and accurate method for discovering congenital color blindness and red-green blindness, each in two forms, complete and incomplete.
- Includes four special plates for tests to determine the kind and degree of defect in color vision.
- Makes use of the peculiarity that in red-green blindness, blue and yellow appear remarkably bright compared with red and green.
- Color plates encased in specially designed album-type books for ease of handling.
- Detailed instructions included.
|Type of product||Eye Chart|
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