Many of us take the ability to see colours for 0 GRANTED, unaware that this feature is fairly uncommon. In fact, only a 17 of biological classes can boast better colour vision, mostly birds and butterflies. Whereas animals and insects rely on these for survival, the 18 purpose of advanced colour perception in humans remains unclear.

Some theories suggest that foraging is the reason we as species have such developed eye for colour. Primates, our ancestors, are largely 19 on fruits and berries as source of food would know if it has 20 enough to safely consume. A more exotic idea is that it is related to snakes. Without being able to tell colours apart it is nearly impossible to know whether a snake is 21 , and should therefore be avoided.

However, not everybody is blessed with the perfect 22 to discern colours. One notable instance is Mark Zuckerberg, the founder of Facebook, who allegedly has some problems with perceiving colours. That’s the reason his social network mostly uses shades of blue in its interface, as Mark 23 finds it easier to tell it apart from other colours. Ultimately, it goes to show that nowadays absence of colour vision is more of an 24 rather that a serious condition that affects your quality of life in a dramatic way.