The Ishihara Color Testing Book developed for color vision testing. Unlike the Ishihara patterns that may be found online and viewed over a computer monitor, this color vision test is designed to produce accurate test results in determining color blindness and the degree of color blindness. Since color reproduction may vary from computer monitor-to-computer monitor, the best and most accurate method of testing for color blindness still comes from official Ishihara album-type books. Unless the computer monitor display administering the test is capable of CRT ICC calibration and regularly degaussed and recalibrated, accurate color and test results may not be possible.
Additionally, home printed versions of the test may yield inaccurate results due to variation in ink cartridge color. Printing of Ishihara color tests should only be done on imaging devices accurately calibrated to CMYK or Pantone color charts.
The Ishihara Color Testing Book is accepted by leading authorities as a simple and accurate method for discovering congenital color blindness and red-green blindness in both complete and incomplete forms. Also known as Protanomaly and Deuteranomaly, "red-weakness" and "green-weakness", respectively, are the two most common types of color deficiency.
It is said that 1 out of 100 males are subject to "red-weakness" and approximately 5 out of 100 males are subject to "green-weakness". In a test, those suffering from red-weakness fail to see the color red with the same power ( saturation or depth of color ) as a normal observer. It is said that Males, in general, experience color blindness at the rate of 12 in 100 while color blind females reportedly test at a rate of 1 in 200.
Choose the 10 plate Color Blindness test for basic testing of adults, children and developmentally disabled individuals. The designs and shapes enable simplified testing of children and those with cognitive conditions where identification of numbers may not be possible. The 10 plate test does not contain any numbers.
The 14, 24 and 38 plate Ishihara tests provide additional pages of numbers and designs to incorporate into the testing process. More comprehensive results can be obtained with the addition of testing plates. The 38 plate test is the most comprehensive, showing the most variation in numeric tests along with 17 pages of designs and shapes.