Developed by Dr. Shinobu Ishihara, the Ishihara Color Blindness Tests have been used for years by ophthalmologists for screening patients for color blindness. These short books consist of a set of colored diagrams with numbers or figures hidden in them.

Those with color blindness will not be able to distinguish the number or figure from the surrounding dots. When used properly, these tests can help you determine the type and degree of color blindness.