Notes

#01 99% of all colorblind people are not really color blind but color deficient; the term color blindness is misleading.

#02 Red-green color blindness is a combination of red-blindness (protan defects) and green-blindness (deutan defects).

#03 Color blindness is more prevalent among males than females, because the most common form of color vision deficiency is encoded on the X sex chromosome.

#04 “What color is this?” is the most annoying question you can ask your colorblind friend.

#05 There are three main types of color vision deficiency: protan, deutan, and tritan defects.

#06 Strongly colorblind people might only be able to tell about 20 hues apart from each other, with normal color vision this number raises to more than 100 different hues.

#07 Colored lenses or glasses can improve color discrimination in your problem areas but can not give you back normal color vision.

#08 Ishihara plates are the best known color blindness tests, but they are not the most accurate ones.

#09 About 8% of all men are suffering from color blindness.

#10 Severity of color blindness is usually divided into the following four categories: slightly, moderate, strong, and absolute.

#11 The terms protan, deutan, and tritan are Greek and translate to first, second, and third.

#12 A father can’t pass his red-green color blindness on to his sons.

#13 Dogs are not colorblind.

#14 Color vision deficiency would be a much better term; but it is not as easy to pronounce compared to color blindness.

#15 There are people which are really suffering from complete color blindness, which is called achromatopsia or monochromacy.

#16 Blue-yellow color blindness would be better called blue-green color blindness, as this are more the problem colors.

#17 There exists every nuance of color vision deficiency severity, starting from almost normal color vision up to complete color blindness.

#18 Protanopia, deuteranopia, and tritanopia are types of dichromacy, which means you have only two different color receptors (cones) compared to three with normal color vision.

#19 If a woman is red-green colorblind, all her sons will also be colorblind.

#20 Colorblind people feel handicapped in everyday life, and almost nobody recognizes this.




What is colour blindness?

Colour (color) blindness (colour vision deficiency, or CVD) affects approximately 1 in 12 men (8%) and 1 in 200 women in the world. In Britain this means that there are approximately 2.7 million colour blind people (about 4.5% of the entire population), most of whom are male.

There are different causes of colour blindness. For the vast majority of people with deficient colour vision the condition is genetic and has been inherited from their mother, although some people become colour blind as a result of other diseases such as diabetes and multiple sclerosis or they acquire the condition over time due to the aging process, medication etc.

Most colour blind people are able to see things as clearly as other people but they unable to fully ‘see’ red, green or blue light. There are different types of colour blindness and there are extremely rare cases where people are unable to see any colour at all.

The most common form of colour blindness is known as red/green colour blindness and most colour blind people suffer from this. Although known as red/green colour blindness this does not mean sufferers mix up red and green, it means they mix up all colours which have some red or green as part of the whole colour. For example, a red/green colour blind person will confuse a blue and a purple because they can’t ‘see’ the red element of the colour purple. See the example of pink, purple and blue pen cases below to understand this effect.