In 1794, John Dalton detailed his own colorblindness. He, like his brother, mistook crimson for green and pink for blue. In the research detailed here, DNA taken from Dalton's preserved eye tissue revealed that he was a deuteranope, lacking the retina's middlewave photopigment. His condition was not discovered until much later. Dalton is now known as the father of modern chemistry because of his work on atomic theory. But he made another important discovery in his life: he was blind! Blindness wasn't very common in England at the time, but it was still more common than today. Out of 100 people, about 7 would be blind. Of those 7, 2 were men: Dalton himself and his brother William. The only woman among the blind was Mary Anning, who was 11 years old when she lost her sight. She became one of the first women fossil collectors in Europe. So blindness was not only common, but also likely responsible for many people being left out of society. This must have been very frustrating for Dalton, since he was such a talented scientist. However, this didn't stop him from publishing several books during his lifetime. The first book he published at the age of 39 was On the Alkaline Water of Derby Valley, which studied the effects of acid rain.