We all know what colour blindness is. There are chances that you know someone who confuses blue with green or shades of green, yellow, purple. While colour vision deficiency is a quite common phenomenon, the complete inability to differentiate between the colours is rarely seen. If you want to know your colour vision is, we have a simple test for you to try out!

Count the number of colours you can see in this picture below.

Source: brightside.me

If you are able to see less than 20 colours, your vision is dichromatic.

This is the kind of colour vision that dogs have. Dichromatic vision means that a person has only two kinds of colour receptor cells in the eyes. It's a vision defect in which one out of three basic colour mechanisms are non-functional. But don't panic, because around 25% of the people in the world are dichromats.

Source: imgur.com

If you can see 20 to 33 colours, you have trichromatic vision.

People with trichromatic vision have three types of photoreceptor cells in their eyes. Such people can see purple, green, dark blue, and red colours very well. Around half of the world's population is trichromatic.

Source: photographyoftheinvisibleworld.blogspot.in

You have tetrachromatic vision if you can see colours between 34 and 39.

Congratulations if you can see more than 34 colours! It means that you have four kinds of cone cells in your eyes and your sensory color space is four-dimensional. Your colour vision is similar to bees and one can differentiate between a majority of the colours. Tetrachromats are likely to have a dislike for the yellow colour. 

Source: popsci.com

So how many colours do you see?