Colour-blindness in Northern Ireland

Colour blindness, also known as colour vision deficiency, is a condition that causes people to see colours differently than most people. People with colour blindness may have trouble distinguishing between certain colours or shades, or perceiving the brightness of colours. For example, they may have difficulty telling the difference between red and green, or see reds as greens and greens as reds. In less common cases, people with colour blindness may have trouble distinguishing between shades of blue and yellow.

Colour blindness is usually inherited through a genetic mutation, and men are more likely to be born with it. It’s a common problem that affects about one in 12 men and one in 200 women. However, it can also be caused by certain eye diseases, brain and nervous system diseases, some medications, or eye or brain injuries.

Testing for Colour Deficiency

Ask for a colour vision test at an opticians if you think you or your child may have a colour vision deficiency, particularly if it started suddenly or is getting worse. Colour vision tests don’t always form part of the routine health service test, but you can ask for them.

Two of the main tests used to diagnose colour vision deficiency are:

• The Ishihara test where you’re asked to identify numbers contained within images made up of different coloured dots
• Colour arrangement where you’re asked to arrange coloured objects in order of their different shades

There are a number of online tests using similar techniques that may help detect a possible problem. But it’s best to have a proper test at an opticians if you have any concerns about your colour vision.

 Living with a Colour Deficiency

Colour vision deficiency isn’t usually anything to be concerned about. Most people get used to it over time. It won’t normally get any worse and it’s rarely a sign of anything serious.

However, it can sometimes cause issues such as:

• Difficulty at school if colours are used to help with learning
• Problems with food, such as identifying whether meat is fully cooked or whether fruit is ripe
• Getting medications confused if they’re not clearly labelled
• Trouble identifying safety warnings or signs
• Slightly limited career choices – certain jobs, such as pilots, train drivers, electricians and air traffic controllers, may require accurate colour recognition

Overall, many people with a colour vision deficiency have few, if any, problems. They can do most normal activities, including driving. There’s currently no cure for inherited colour vision deficiency, although most people are able to adapt to it over time.

It may help to:

• Tell your child’s school if they have problems with their colour vision, so learning materials can be adapted
• Ask your friends or family for help – for example, they can help you choose matching clothes and check whether food is safe to eat
• Install good quality lighting in your home to help you distinguish colours
• Make use of technology – computers and other electronic devices often have settings you can change to make them easier to use, and there are a number of mobile phone apps available that can help identify colours for you