What is colour blindness? Colour blindness, or colour vision deficiency, is the inability or decreased ability to see colour, or perceive colour differences, under normal lighting conditions. Colour blindness affects a significant percentage of the population. There is no actual blindness but there is a deficiency of colour vision. People with colour blindness aren’t aware of differences among colours that are obvious to the rest of us. People who don’t have the more severe types of colour blindness may not even be aware of their condition unless they’re tested in a clinic or laboratory.
What is Colour Blindness?
Most of us share a common colour vision sensory experience. Some people, however, have a colour vision deficiency, which means their perception of colours is different from what most of us see. The most severe forms of these deficiencies are referred to as colour blindness.
Inherited colour blindness is caused by abnormal photopigments. These colour-detecting molecules are located in cone-shaped cells within the retina, called cone cells. In humans, several genes are needed for the body to make photopigments, and defects in these genes can lead to colour blindness.
There are three main kinds of colour blindness, based on photopigment defects in the three different kinds of cones that respond to blue, green, and red light. Red-green colour blindness is the most common, followed by blue-green colour blindness. A complete absence of colour vision —total colour blindness – is rare.
Sometimes colour blindness can be caused by physical or chemical damage to the eye, the optic nerve, or parts of the brain that process colour information. Colour vision can also decline with age, most often because of cataract – a clouding and yellowing of the eye’s lens. Now you know What is Colour Blindness? lets examine our eyes by taking colour blindness test.
COLOR BLINDNESS TEST – (PLATES 01 – 17)
COLOR BLINDNESS TEST – (PLATES 18 – 24)