One in 12 men are colour blind (and one in 200 women) which, by any standards, is a lot. Yet not many people are aware of this statistic, probably because colour vision deficiency (CVD) is a hidden condition. Sometimes colour blind people themselves don’t realise they have this condition – they simply think everyone sees colours the way they do. But living with CVD can have serious repercussions for a person’s safety, their education, professional and social life, and, in some cases, their self-esteem.

People with the most prevalent forms of CVD confuse all sorts of colour combinations, not just reds and greens. So, on an average day, they might bite into an unripe banana, they may confuse the recycling bins, documents corrected in red ink at work could be meaningless, and watching Liverpool play footie on the box could be more of a challenge than a pleasure (their all-red home kit blurs into the green pitch).

Not insurmountable problems perhaps, but day after day, and in certain jobs and situations, they are definitely a frustration and can constitute a disability – and failure to assist people with this disability, whether intentional or not, can be discriminatory.

Images copyright Colour Blind Awareness

Ignoring the needs of people with colour blindness can also be a form of indirect sexual discrimination. Girls could be considered to have an advantage over boys in all kinds of situations because so many more boys struggle with undiagnosed colour blindness, or a lack of support post diagnosis, compared with the small numbers of girls who are colour blind.

A key area where CVD causes difficulties is at school. In the educational environment, CVD can impact negatively on a pupil’s performance, and ultimately their opportunities going forward in life, if the classroom and teaching methods are not adapted to meet their needs. For example, traffic-light coding in primary schools is incomprehensible to children with CVD, colour-coded pie charts are impossible to navigate, while chemistry students will be lost when it comes to colour-reliant experiments.

“People, including teachers, don’t realise how widespread the problems can be in school,” says Kathryn Albany Ward, founder of Colour Blind Awareness. “It can affect performance across the whole curriculum including, geography, maths, ICT and even languages.”

'What's most annoying is when people don't understand why it's a problem' Marcus, aged 9, says: “At school I get confused sometimes in lessons like geography - flags and maps can be difficult to understand. In food tech, I always have to ask my partner if something is cooked and the science stuff I look at online is sometimes challenging. It's also really annoying when I'm playing football and the cones aren't the right colour. But what's most annoying is when people don't really understand why it's a problem.” Marie, his mother, says: "As a parent of a colour blind child I'm continually shocked and appalled by the lack of awareness and understanding of this condition in education. It is basically as prevalent as dyslexia, yet teachers generally receive no training and children are no longer screened. It beggars belief in a 21st century classroom where colour is used constantly that this is not on the radar of most schools.”

Regrettably, screening for CVD is no longer a mandatory part of school entry, nor is a colour vision test part of the NHS eye test for children. As a result, some youngsters can struggle for years at school if a parent or teacher has not spotted there is something wrong. It can also affect their career prospects - and therefore their choice of subjects as they advance into higher education – because certain jobs and professions will be off limits, at worst, or complicated, at best, for people with CVD, such as working as a pilot, electrician or in medicine.

The good news is that, thanks to sustained efforts by Colour Blind Awareness in recent years, many sectors of society are starting to take notice. Significant advances are being made in football, with UEFA and the English FA leading from the front, raising awareness and implementing CVD-friendly strategies. Educational institutions have been slower on the uptake, but CBA has written best practice information leaflets and runs workshops for teaching professionals which it is hoped may begin to make a difference soon.

In reality, we can all play a part in helping to prevent discrimination against those with colour blindness. If you come across information or methods that can’t be interpreted without colour recognition – a danger sign, an occupied toilet indicator, computer software – why not point it out to the relevant body or, if necessary, log a complaint? And keep an eye on young people in your entourage, in particular young boys, for any signs of trouble with colour recognition (see the tips below). If in doubt, ask an optician to test for CVD. Like most things in life, once a difficulty is identified, you can work out strategies to help manage the negative impact.

'Bombarded with graphs, images, figures and tables' Oliver Daddow, Assistant Professor in British Politics and Security in the School of Politics and International Relations at the University of Nottingham, reveals the frustration he has felt since joining Twitter earlier this year. “I am bombarded daily with graphs, images, figures, and tables that are a staple of Twitter feeds for the politically interested. Opinion polls, pie charts of public expenditure, Brexit negotiation flow charts etc; all get the full colour treatment. “The problem is that, being colour blind, I can only read around half of them at best. I can spend time deciphering what is going on in a few of the remainder. The rest remain an impenetrable mass of lines and words. “With around one in 12 men and one in 200 women colour blind in some form, it is time designing for the colour blind became a much more integrated component of academic and media training. Bad graphic design prevents significant numbers of the population from accessing data. “If all members of a society are to engage equally on matters that affect all of us, then designing politics-related graphics so they can be read by everyone would be a hugely important step for young and old alike.”

What causes CVD?

Essentially, CVD a deficiency in one of the three types of specific cone cells in our eyes that absorb red light, green light and blue light respectively. Most cases of CVD arise from a defect in the red or green cone types – commonly known as red/green colour blindness – but colour blindness can affect many other colour combinations. The generally held view that colour blind people only confuse reds with greens is a myth.

Why does CVD affect men and boys in greater numbers?

Colour blindness is far more prevalent in males than females (1 in 200 women is colour blind) because the condition is inherited via the X chromosome. If a male inherits the colour blindness gene on his single X chromosome, he will be colour blind. If a female inherits colour blindness on just one of her two X genes, the good (non colour blind) X overrides the bad X so she won’t be colour blind but she will be a carrier, with a 50% chance of passing the bad gene down to her sons. If, however, both her X chromosomes carry the gene, she will be colour blind.

How to spot CVD?

There are a few tell-tale signs to look out for that may indicate CVD. For example if someone:

Needs more time, or looks for other clues, to process information that uses colour

Appears to regularly misunderstand instructions (is it because colour is involved?)

Has difficulty ‘seeing’ colours in PowerPoint presentations or data communication ( see personal testimony below )

) Has difficulty using software programmes (many website pages uses colour text or graphics on a colour background that can be very difficult for people with CVD to ‘see’)

Appears confused by coloured sports equipment – e.g. green bibs, red cones, blue court markings (see below)

Isn’t sure when meat is cooked

For more information, visit colourblindawareness.org