Chemist John Dalton: Colorblindness

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“Colorblindness” is a term that would have one believe its sufferers only see in monochrome, but in all truth it describes an umbrella of conditions ranging from having trouble with recognizing differences between some colors (red and green are common) and total, actual inability to see in colors. Though the disease is relatively rare, and its effects are harmless, research has been ongoing since the 18th century. According to, chemist John Dalton pioneered the study of colorblindness as he himself was affected, and naturally he wanted to know why he couldn’t see colors like others did. Two centuries have seen many advances, going from Dalton’s proposal of affected individuals having tainted fluids in their eyes that “filtered” their vision to the modern understanding of broader genetics and the anatomy of the eye. Red-Green colorblindness is caused by a gene carried on the X chromosome, which means that the disease is more common in men, as they have only one X chromosome compared to a woman’s two. Women can be carriers, however, and since the gene for colorblindness is subordinate to the normal gene for color vision, they will be unaffected. The faulty gene which causes colorblindness affects the light receptors (cone cells) of the eyes’ ability to perceive light. With red-green colorblindness, for example, the cones which perceive red wavelengths and green wavelengths are defective or inadequate in their jobs, and thus an individual with red-green colorblindness will have trouble seeing the colors red and green. According to PubMed Health, the above occurs when only one type of cone cell is affected. Victims of the much rarer blue-yellow type color blindness have more than one type of cone cells that are affected... ... middle of paper ... ... from Causes of color blindness. (n.d.). Retrieved January 26, 2014, from Colour Blind Awareness website: Daltonism - named after John Dalton. (2006, April 9). Retrieved January 26, 2014, from Colblindor website: The gale encyclopedia of science. (n.d.). In K. L. Lerner (Ed.), Gale. Retrieved from Gale Science in Context database. (Accession No. CV2644030529) Ishihara, S. (n.d.). Ishihara test plate #29 [Photograph]. Retrieved from Vorvick, L. J., M.D., & Lusby, F. W., M.D. (Eds.). (2011, June 1). Color blindness. Retrieved January 26, 2014, from PubMed Health website:

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