Vision and the ability to differentiate between colors in the spectrum are extremely essential in order to meet day-to-day chores of life. Human eye contains two specialized kinds of photoreceptor cells namely rods and cones that actively participate in regulating these activities. Any abnormalities or errors in these cells can result in the individual being unable to identify colors, a medical condition better known as color blindness or color vision defect.
Abnormalities in the color vision can occur either due to genetic disorder or acquired.
Genetic defects or inherited disorders are primarily as a result of mutated genes. Inherited color vision defect is primarily an X-linked disorder that is mostly prevalent in males. This is because males have only one single X-chromosome while females carry two sets of X-chromosomes. Hence, if the X-chromosome transferred to the male contains mutations that can cause color blindness, the child is definitely going to suffer from the disease. In case of females, chances of both the chromosomes carrying mutations are practically negligible. There are three different types of inherited color vision defects; namely monochromacy, dichromacy and anamolous trichromacy.
There are different reasons due to which a person can acquire color blindness and color vision defects. Some of these include any disease in the eye, injury to the retina, ageing, injury to the optic nerve, damage to the brain, damage caused due to excessive exposure to UV radiation or even as a result of side effects of certain medications.
Defects in the color vision were first identified and reported in 1798 by John Dalton, an English chemist. As a result, these diseases are sometimes referred to Daltonism. Today, detection and diagnosis of color blindness is extremely simple and easy. There are certain specialized color vision tests such as pseudoisochromatic plate tests and arrangement tests that are routinely used to screen for inherited color blindness disorders.