Colour blindness: types and diagnosis
Colour vision deficiency (CVD) - better known as colour blindness - is a common condition, affecting around 3 million people in the UK. It affects men more than women and is usually genetic, meaning it is caused by mutations in DNA and can be passed from parents to children. Here, we explore the causes and types of colour blindness, as well as how to get a diagnosis.
What causes colour blindness?
Colour blindness is caused by a mutation in the cone cells within the eye. There are three types of cone cells that each detect different wavelengths of light and therefore different colours: red (long wavelengths), green (medium wavelengths) and blue (short wavelengths).
The condition is most commonly inherited, meaning the majority of people are born with it. However, it can also develop as a result of an underlying health condition, use of certain medications, exposure to harmful chemicals or the aging process.
Types of colour blindness
Contrary to what the term ‘colour blindness’ suggests, those who have colour vision deficiency (CVD) do not only see in black and white. This condition is called monochromacy and is extremely rare. Usually those with CVD struggle to distinguish certain colours depending on which of their cone cells has developed a mutation.
- Red-green CVD
Red-green CVD is the most common type of colour blindness and is where either the red or green cone cells don’t work fully - or even at all. This results in difficulty differentiating reds, greens and browns; oranges and yellows; blues and purples; and/or greys and pastel colours. The colours may appear duller, and sometimes dark reds can be confused with black.
- Blue-yellow CVD
Blue-yellow CVD is less common, affecting less than 1% of people, and occurs when only the blue cone cells are not working optimally or at all. It causes confusion between blues, greens, yellows, oranges and violets. Colours may also appear duller or paler.
Diagnosis and treatment
Red-green CVD can be diagnosed during childhood, although school eye tests do not include screening for colour blindness. With that in mind, it’s advisable to seek out the ‘best eye test near me’ and ask the optometrist to test your child’s colour vision if you have concerns.
There is not currently a cure for CVD, but there are several ways it can be managed:
- Special CVD glasses with tinted lenses are available, which enhance colour separation to make it easier to distinguish different shades.
- Various smartphone apps use your device’s camera to help identify different colours.
- Many individuals adopt strategies such as labelling colours, using patterns and optimising contrast in order to help them navigate the world.
Comprehensive eye tests in London
If you’re looking for the best opticians for eye tests for yourself or your child, visit The Eye Establishment in Kensington and Chelsea. Our expert optometrists offer comprehensive sight tests, checks for colour blindness and reliable diagnosis of issues. Search ‘best eye test in London’ or book with us directly for friendly, professional care and access to a range of eyewear from premium brands.