Who is Professor Hallux?

Professor Hallux is a scientist who is really curious about everything to do with the human body!

With the help of Nurse Nanobot he wants to find out everything he can about how the human body works.

Watch this video in which Professor Hallux and Nurse Nanobot find out what colour blindness is and how it works…

After that you should have a better idea about what colour blindness is

What is colour blindness?

This is a condition some people have which makes them see colours differently.

Do colour blind people see everything in black and white?

No, they still see colours they just see colours differently to others.

For example, the most common form of colour blindness is red-green colour blindness. Someone with this condition will have trouble telling the difference between red and green.

What makes someone colour blind?

It’s all to do with how the light that goes into your eye is interpreted.

First we need to know how a normal eye works.

When light goes into the eye it hits the retina.

The retina has special cells called rods and cones that detect the light that comes into the eye before sending that information to the brain to form the pictures we see.

Rods

The rod cells measure the brightness and shade of the light that comes into our eyes.

Cones

The cones detect the colours of the light that enters the eye.

There are 3 types of cone cells: green, blue and red.

The green ones detect green light, the blue ones detect blue light and the red ones detect red light.

The cones send the information about the colours they detect to the brain so that we know what colour the thing we’re looking at is.

If there’s only 3 colours of cone cells how come I can see millions of different colours?

Because the green, blue and red cone cells work together so that you can see all the colours.

It’s a lot like mixing paint, for example if you mix red and blue paint you would get purple. This is what the cones do too, if something you look at is purple then the red cone and blue cone would work together to make purple.

This is how the cone cells are able to relay any colour you see to your brain.

Okay, so I know how a normal eye sees colour but what happens in the eye of someone who’s colour blind?

It’s all to do with the cone cells.

A colour blind person will have more or less cones than normal or their cone cells will just be faulty and send the wrong information to the brain about the light they’re detecting.

This can mean that people who are colour blind have trouble seeing the difference between certain colours.

This is why someone with red-green colour blindness will have trouble telling the difference between red and green.

How can you tell if someone is colourblind?

Optometrists will use special charts made up of dots in different colours that have patterns on them like this…

People who are colour blind will find it more difficult to see what the number or shape is.

Your mission is to complete this quiz all about colour blindness…

Click here to see the next mission about how our eyes see in 3D!

In the mean time, if you want more from professor Hallux then you can find more here.