Also known as color vision deficiency, is the decreased ability to see color or differences in color. Color blindness can make some educational activities difficult. Buying fruit, picking clothing, and reading traffic lights can also be more challenging. Problems, however, are generally minor and most people adapt. People with total color blindness may also have decreased visual acuity and be uncomfortable in bright environments.
The most common cause of color blindness is a fault in the development of one or more of the three sets of color sensing cones in the eye. Males are more likely to be color blind than females as the genes responsible for the most common forms of color blindness are on the X chromosome. As females have two X chromosomes, a defect in one is typically compensated for by the other, while males only have one X chromosome. Color blindness can also result from physical or chemical damage to the eye, optic nerve, or parts of the brain. Diagnosis is typically with the Ishihara color test; however a number of other testing methods also exist.
John Dalton was the first scientist to take academic interest in the subject of color blindness. He was born September 6, 1766 in Eaglesfield, England and died July 27, 1844 of paralysis. One of the first scientific papers John Dalton published was titled “Extraordinary facts relating to the vision of colours” and released in 1793.
Starting his career as a teacher he got interested in meteorology and mathematics. As Jonathan, his seven years older brother and John himself both were affected by red-green color blindness he also started some observations and researches about color vision
“That part of the image which others call red appears to me little more than a shade or defect of light. After that the orange, yellow and green seem one colour which descends pretty uniformly from an intense to a rare yellow, making what I should call different shades of yellow”
He postulated that shortage in color perception was caused by discoloration of the liquid medium of the eyeball called aqueous humour. According to his research he believed that the aqueous humour was bluish and therefore filtered out all the colors. His observations and writings formed the expression Daltonism as a common wording for color blindness.
Through his lifetime John Dalton became a well known and respectable chemist and physicist and was one of the early proponents of the Atomic Theory. One of his last wills was to get an autopsy of his eyes after death. Unfortunately there wasn’t any bluish liquid found. It was his final experiment and proved that the condition called Daltonism is not caused by the eye itself, but some deficient sensory power.
There is no cure for color blindness. Diagnosis may allow a person’s teacher to change their method of teaching to accommodate the decreased ability to recognize color. Special lenses may help people with red–green color blindness when under bright conditions. There are also mobile apps that can help people identify colors.
Red–green color blindness is the most common form, followed by blue–yellow color blindness and total color blindness.Red–green color blindness affects up to 8% of males and 0.5% of females of Northern European descent. The ability to see color also decreases in old age.Being color blind may make people ineligible for certain jobs in certain countries. This may include pilot, train driver, and armed forces. The effect of color blindness on artistic ability, however, is controversial. The ability to draw appears to be unchanged and a number of famous artists are believed to have been color blind.