Daltonism refers to the red-green type of colorblindness, also known as deuteranopia or deuteranomaly. The term takes its name from John Dalton (1766-1844), a chemist and physicist. Dalton was born in a small village in Cumberland, England, where his father, Joseph, worked as a weaver under challenging financial conditions. He received his education from both his father and John Fletcher, a teacher at a Quaker school. When Fletcher retired in 1778, Dalton succeeded him as a teacher. By 1793, he became a mathematics and natural philosophy instructor at New College in Manchester. In 1803, Dalton introduced his law of partial pressures, stating that the total pressure of a gas mixture equals the sum of the pressures each gas would exert alone. Dalton is also renowned for developing the Atomic Theory. Known for his reserved nature, Dalton seldom participated in social activities, except for a weekly game of bowls on Thursday afternoons. Dalton's first scientific paper, titled "Extraordinary facts relating to the vision of colours, with observation" (Mem Literary Philos Soc Manchester 5: 28-45, 1798), documented his and his brother's struggle with red-green colorblindness. This publication is recognized as the earliest account of this type of colorblindness.
