Color blindness according to data available on the most comprehensive resource affects, quite a lot of us — around 0.5% of women and 8% of men — suffer from inaccurate perceptions of color.
The effects of color vision deficiency can be mild, moderate or severe depending upon the defect. If you have inherited color blindness your condition will stay the same throughout your life – it won’t get any better or worse.
The retina of the eye has two types of light-sensitive cells called rods and cones. Both are found in the retina which is the layer at the back of your eye which processes images. Rods work in low light conditions to help night vision, but cones work in daylight and are responsible for color discrimination.
There are three types of cone cells and each type has a different sensitivity to light wavelengths. One type of cone perceives blue light, another perceives green and the third perceives red. When you look at an object, light enters your eye and stimulates the cone cells. Your brain then interprets the signals from the cones cells so that you can see the color of the object. The red, green and blue cones all work together allowing you to see the whole spectrum of colors. For example, when the red and blue cones are simulated in a certain way you will see the color purple.
Normal Vision – A person with normal vision sees the world around them in these colors.
Deuteranomalia – is the most common form of color blindness. Around 4.63% of men suffer from it and in many cases don’t even realize. It’s clear from the photo that the colors have lost some of their brightness, especially with regard to green and red.
Protanopia is a less-widespread form of color blindness — only around 1% of men experience it. All shades of green and red appear somewhat faded, whilst blue and yellow shades remain virtually unchanged.
Tritanopia is a very rare form of color blindness affecting men and women to an equally small degree. Those who experience it see the world in greenish pink tones.
As for total color blindness, it certainly exists, but it’s extremely rare: only 0.00003% of the world’s population has it.