John Dalton was a chemist primarily known for his development of the modern atomic theory. "Daltonism" is another word for color blindness because Dalton was colorblind. In common with his brother, he confused scarlet with green and pink with blue. Dalton supposed that his vitreous humor was tinted blue, selectively absorbing longer wavelengths. He instructed that his eyes should be examined after his death, but the examination revealed that the humors were perfectly clear.
