About colour blindness
Colour blindness is when you can't see some colours normally.
Red-green colour blindness is the most common type. This is when you have trouble telling the difference between greens, browns, reds and oranges.
Blue-yellow colour blindness is rare. People with this type of colour blindness have trouble telling the difference between blues and yellows.
Nearly all children with colour blindness are boys. And about 8% of boys have red-green colour blindness. Boys usually inherit colour blindness from their mother's side of the family.
Causes of colour blindness
Cone cells in our retinas help us see differences between colours.
There are three types of cone cells. Each type responds to a different colour - red, green and blue.
In a person who is colour blind, only two out of three of these types of cones work normally.
Symptoms of colour blindness
If your child has colour blindness, he might have trouble telling the difference between reds, greens, browns and oranges after about the age of four. He might say that two different colours are the same or struggle to separate things according to colour.
Colour blindness might become obvious at preschool or school, especially when your child is doing activities like sorting blocks, colouring or copying different coloured text.
Although children with colour blindness confuse some colours, their vision should be clear.
Colour blindness stays the same over time. It doesn't get worse or better.
Does your child need to see a doctor about colour blindness?
If you think your child might be colour blind, see your GP or optometrist, who can organise special tests.
If there are other people in the family with colour blindness, you might also wish to have your child tested.
Treatment for colour blindness
There's no cure for colour blindness. But it isn't a serious condition, because children learn colours by association.
It's a good idea to let your child's teachers know that your child has colour vision problems, so the teachers can choose teaching activities that don't involve spotting colour differences.
As children with severe colour blindness get older, it might be unsafe or hard for them to do jobs where colour identification is important - for example, handling electrical wires or telling warning lights apart.