Color blindness, is a color vision deficiency, which causes some people trouble to identify the difference between some particular colors and their shades.
However, color blindness, as the name may suggest, does not actually mean a total lack of color sensitivity in a person. Most color blind people cannot tell red from green. For others suffering from a rare form of the disorder, it is blue and yellow. Normally it is seen that people who can not differentiate blue from yellow also have difficulty with red and green.
It is vital to understand here that this color vision deficiency is actually the off shoot of some malfunctioning or missing cone cells on the retina of a person’s eyes. In a normal person, the retina; has three types of cone cells – the red, blue and green cones. These cone cells are sensitive towards the three colors and also to those obtained from their combination.
Malfunctioning of any one of these cones may cause a person to misinterpret colors; for, the brain is getting all the wrong signals as far as shades are concerned. In some cases, a person may not be able to identify any color at all. This is a rare form of color blindness called achromatopsia, where a person is seeing things in white and black.
Color blindness is rarely acquired and predominantly inherited. Either of a color blind person’s parents must have been carrying the gene, to have passed it on. Mostly women are the carriers of this gene and men are the ones to inherit it; thus, making it a gender biased disorder.
The reason for this is simple. The gene for color blindness is carried on the X chromosome and men have only one of these while women have two. So while women have one chromosome compensating for the defective one; men do not have much of a choice in this regard. Other factors like - poisoning, side effects to a drug, macular degeneration, etc. may also sometimes cause color blindness in people.
Although, color blindness is a lifelong condition with no known cure so far; people suffering from it need to inculcate lifestyle changes in order to deal with the situation.
Scientists are working on a gene cure for color blindness. It has been reported that they were able to restore complete color vision to an adult monkey suffering from the disorder by birth and humans might be next in line soon.