What is colour blindness?

Colour blindness is the inability to see certain colours in the usual way. People who are colour blind will confuse some colours and they will not see some colours as brightly as people with normal vision.

The condition is usually inherited and is there from birth. It can also arise from damage to the brain or eyes.

Types of colour blindness

There are 3 types of colour blindness.

Red–green colour blindness

Red-green colour blindness is the most common form of colour blindness. It is usually inherited and mostly affects males. It means you find it hard to tell reds from greens.

Blue–yellow colour blindness

Blue-yellow colour blindness is less common than red-green colour blindness and affects only about 1 in 20 people with colour blindness. It means you find it hard to tell blues from yellows. It affects both men and women.

Complete colour blindness

If you have this, you don’t experience colour at all. Complete colour blindness is extremely rare.

Colour blindness diagnosis

Your doctor or optometrist can check you for colour blindness. The most common way is by using specially designed cards with coloured dots in patterns you should recognise if you don’t have colour blindness.

How does colour blindness affect daily life?

If you have colour blindness, it might cause you some problems, but others you will learn to overcome.

For example, if you have red-green colour blindness, you might have trouble telling if red meat is cooked.

And you might have trouble seeing the colours on traffic lights. But you can learn that the red is at the top and the green is at the bottom.

Children with colour blindness might need help with schoolwork as educational materials are often colour-coded.

If you are colour blind, some occupations will be difficult. These include being a pilot, long distance driving or work where colours are important, like graphic design.

If you’re concerned about colour blindness, see an optometrist. Your doctor can also refer you to an ophthalmologist (eye specialist). They can recommend ways to manage colour blindness, with tools like special lenses or software.