Colour Blind
People who cannot distinguish between different colours are said to be Colour Blind. A person suffering from colour blindness may be blind to one, two, or all the three primary colours. The primary colours are Blue, Green, and Red.
Types of Color Blindness
Blindness to Red is called Protanopia, to Green Deuteranopia, and to Blue is Tritanopia. The Protanopic people are ordinarily unable to distinguish between Red and Green, while those suffering from Deuteranopia can not distinguish between Blue and Yellow. Tritanopic persons are unable to see the Green colour.
People who are Colour Blind are usually unaware of this fact. Colour Blindness is tested with the help of special charts made of different colours. If a person cannot identify a particular colour from these charts, they are said to be Colour Blind to that colour.
Colour Blindness Treatment
Colour Blindness is a hereditary disease. There is no treatment for it. Some special coloured glasses and contact lenses are available, which can help.
Colour Blindness cannot be treated because of the abnormality of the colour-sensitive cones present in the eye’s retina. In a normal person, these cones are sensitive to three primary colours – Red, Green, and Blue. Different colours are produced by mixing of these three colours. If cone-cells are insensitive to any particular colour, they cannot be stimulated by that colour, and as a result, one becomes blind to that particular colour.
Colour Blindness is a more common occurrence in males than in females. About six percent of males and one percent of females in the world suffer from this defect. Colour Blindness does not affect the power or range of eyes. But it can be particularly dangerous for pilots and drivers as they would not be able to distinguish between Red and Green signals. And so Colour Blind people are never employed for such jobs.
The famous chemist Dalton was also Colour Blind, and that is why this defect is also sometimes called ‘Daltonism.’