Colour blindness: What you should know

Finding out your child is ‘colour blind’ can be a concern for some parents who might be worried their child will be disadvantaged. The term is misleading however, because it has little to do with blindness. It is actually referred to as ‘colour deficient’ because it most often impacts the way people see selected colours.

As many as eight per cent of males and 0.5 per cent of females are known to be ‘colour blind’; that’s one in 12 men and one in 200 women.

However, according to Vanessa Honson, Optometrist from UNSW Optometry Clinic, they see only a narrow range of colours.

"Colour blindness is typically inherited genetically and carried recessively on the X chromosome. A father can't pass his red-green colour blindness on to his sons. But if a woman is red-green colour blind, all her sons will also be colour blind," Ms Honson says.

How to tell if your child is colour vision deficient

There are several ways a parent can tell if their child is colour vision deficient.

“Mainly from observations of how their child uses colours in drawing, or if they occasionally pass a different coloured object to their parent from the one they were meant to,” Ms Honson says.

“Sometimes parents tell me they knew from clothing choice, and in some cases, it is the child’s teacher who has noted some of these signs.

“Children aged 2-6 years may not show accurate colour naming, even with the primary colour names (not shades). Colour is a concept rather than an object, and most objects can be described with different colours.

“This means that if a child doesn’t always get the colour name correct, it does not mean they have a colour deficiency. However, painting the sky purple, or grass brown can be signs that a colour deficiency is present.”

Supporting children with colour vision deficiency

When it comes to supporting the learning of children with colour vision deficiency, Ms Honson says there should be a greater awareness and understanding of the red-green congenital colour deficiencies - mostly that those affected are not truly ‘colour blind’ and can see some colours.

“Labelling charts or using redundancy in graphs may help, labelling boxes rather than relying on colours to distinguish differences, asking children to let the teacher know if they have any difficulty in understanding any tasks where colour is used to differentiate points, and even using contrast differences rather than relying on colour alone,” Ms Honson says.

Examples can include:

• avoiding red writing on a dark background
• using graphs with horizontal and vertical stripes as well as colour
• Make sure that the maths program or any other computer aided learning program does not involve a lot of colour interpretation.

The ongoing issues for a child who is colour deficient will vary from child to child.

Ms Honson says because most children don’t want to appear different from their peers (and to avoid being teased) they may try to hide their condition.

“If they’re not aware of their condition, they may feel confused with their ability to learn and it may affect their self-esteem. It’s always best that all children have a full eye examination at an early age - both preschool age, and again in the early primary years.

“In this way, any congenital eye condition (including colour deficiencies) may be detected as early as possible and parents and teachers can then be informed. Whilst the type and severity of the colour deficiency may need to be confirmed at an older age, at least the early detection will help parents and teachers change some approaches to teaching.”

“I recommend that parents do not discourage children when they are young with any vocation, as this may change when they are older. It’s okay to say to the child that they do see colours differently from others.”

Daily living and ongoing issues may present in the way of clothing choices, choosing certain foods or knowing when food such as meat is fully cooked.

“As a society, we increase the level of difficulty by using colour more and more to distinguish features, for example, when an instrument is charged (changing from orange to green), when car spaces are vacant (red and green again), maps and signs, colour graded images (weather maps are a good example but in imaging technology colour grading is increasingly used to present different regions of information). This will impact on the time necessary for the colour deficient individuals when carrying out their job,” Ms Honson says.

The case for vision testing programs

While each state in Australia has a vision testing program for primary school children, colour vision is not tested. But people can take their child to an optometrist for a test and there are online tests you can do at home.

“It would be lovely to also create a program where we could go out to schools and discuss this issue with teachers and children - I feel it would be of great benefit to all involved, not just children with colour deficiencies,” Ms Honson says.

“It may reduce the amount of teasing, and children with colour deficiencies may grow in their self-esteem."

Resources:

Colour Blindness Simulator

Colour Blind Test