What is colour blindness?

Colour blindness, also known as colour vision deficiency, is a condition characterised by the inability to perceive certain colours in the typical way. This condition occurs when there is a problem with the cones in the retina of the eye that respond to different wavelengths of light.

Types of colour blindness

There are two main groups of colour blindness, inherited and acquired. 

Acquired colour blindness can occur due to certain diseases such as macular degeneration, cataracts, diabetic retinopathy or other retinal conditions. 

Some medications can also induce colour blindness as well as some chemicals which may damage the retina or optic nerve.  

Inherited colour blindness affects males more frequently than females because the genes responsible for colour vision are located on the X chromosome. Therefore, as males have only one X chromosome, while females have two, making them less likely to inherit two faulty copies of the gene. 

The most common type of inherited colour blindness is red-green colour blindness, where individuals have difficulty distinguishing between red and green colours. Another type is blue-yellow colour blindness, which is less common. Total colour blindness, where individuals see everything in shades of grey, is very rare.

Colour blindness can present challenges in certain situations. However, many people with colour blindness learn to adapt and compensate for their condition using cues such as brightness, hue or context. 

Myths associated with colour blindness

Myth: Colour blindness means seeing everything in black and white 

This is one of the most prevalent myths. In reality, very few people with colour blindness see the world entirely in black and white. Instead, they typically have difficulty distinguishing between certain colours, such as red and green or blue and yellow. 

Myth: Colour blindness affects everyone equally 

There’s a misconception that colour blindness affects everyone in the same way. In fact, there are different types and degrees of colour blindness. The most common form is red-green colour blindness, followed by blue-yellow colour blindness. Some people may also have difficulty seeing all colours, a condition known as monochromacy. 

Myth: Colour blindness only affects men 

While it’s true that colour blindness is more common in men, women can also be colour blind. However, it’s less frequent in women because the genes responsible for colour vision deficiency are located on the X chromosome. Since women have two X chromosomes, they are less likely to inherit two copies of the gene mutation responsible for colour blindness. 

Myth: Colour blindness is a rare condition 

Colour blindness is more common than many people realize. Approximately 8% of men and 0.5% of women with Northern European ancestry have some form of colour vision deficiency. It may vary in prevalence among different populations and ethnic groups. 

Myth: Colour blind people cannot drive

While certain types of colour blindness may pose challenges for driving, many colour-blind individuals can obtain a driver’s license and drive safely with the help of accommodations such as special lenses or relying on other visual cues like the position of traffic lights. 

Myth: Colour blindness can be cured 

Currently, there is no cure for colour blindness. While certain aids such as colour-correcting lenses or smartphone apps can help individuals with colour vision deficiency distinguish colours more easily, they do not provide a permanent solution. Additionally, gene therapy research is ongoing, but it’s still in the experimental stage. 

For more information

Always speak to your GP and eyecare professional about the best treatment options for you.

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