John Dalton was born in the 18th century and was recognized mainly for his work on the chemical atomic theory and “Dalton's Law” for the partial pressure of gases. However, during his lifetime he was already recognized for his theories on “colorblindness,” with which he was afflicted. He was perhaps the first to report personal observations from experimentation on his color vision deficiency. His theory regarding its pathogenesis was posthumously proven to be incorrect after observations performed on his enucleated eyes. Further generations later, DNA analyses by PCR conclusively recorded the specific color deficiency (deuteranopia) with which Dalton was affected.