It is estimated that there are 300 people in the world with color blindness, most due to genetics, some cases due to complications of diabetes, multiple sclerosis, aging or side effects of medications. There are currently highly accurate and commonly used ways to test for color blindness. How to test for color blindness? 1. Qualitative color blind test (Enchroma, Ishihara) The most used qualitative test for color blindness is the Ishihara color vision test. This method was invented and published by Japanese ophthalmologist Shinobu Ishihara in 1917. Specifically, Ishihara plate testing is a standard and highly accurate method. The Ishihara plate helps test for red-green color blindness. The Ishihara test consists of 38 clear pictures created by unique and colorful random dots. The simple way to check is to look at the board and say the visible number. Each plate will contain information that people with color blindness will see a different result than normal people. Based on the results, the doctor will conclude what color blindness you have. Some special plates are used to diagnose color blindness in children who cannot yet read numbers or letters. Based on the Ishihara color blindness test, the Enchroma color blindness test determines the type and degree of color blindness a person has. This is a test created by professor Shinobu Ishihara at the University of Tokyo, combined with a computer adaptive algorithm to measure the type and degree of color blindness. The test has modes for adults and children from 5 years old, with 3 main types of color blindness: green blindness, red-green color blindness and yellow-green color blindness. 2. Quantitative color blindness test Quantitative color blindness test aims to analyze in more detail color blindness and the patient's ability to accurately recognize colors. The most commonly used quantitative test for color blindness is the Farnsworth-Munsell 100 color test. https://colorblind-test.io The test consists of 4 trays containing many small discs of different colors. The tester needs to arrange the colored discs in ascending order of color. To get accurate results, the test should be done in a place with natural light, the colored discs should be replaced regularly and numbered on the base to make checking results easier. The test helps detect color blindness and its severity. 3. Other methods In addition to the above two methods, there is also an online color blindness test. The online color blindness test is a version of the Ishihara qualitative color blindness test. However, online color blindness testing makes image quality unstable and can lead to errors. Therefore, to get the most accurate results, see an ophthalmologist to test for color blindness under appropriate lighting.