Colour blindness (also known as colour deficiency or CVD), is an inherited condition that affects the way that colours are perceived. Sufferers often see some colours differently or are unable to see them at all.
There are different causes of colour blindness, however for the vast majority of sufferers the condition is genetically passed down by the mother. It can also be the result of the presence of other diseases such as diabetes or can be acquired over time due to certain factors such as medications and age.
The condition is found on the X chromosome and is more commonly found in men rather than women, affecting around 8% of men (1 in 12) and 0.5% of women (1 in 200) in the world . Males only have one X chromosome whereas women have two, meaning that if the chromosome is effected in men they will suffer from colour blindness in comparison to women who will still have fully functioning colour vision.
Most people that suffer from colour blindness can see as clearly as others but are unable to fully perceive red, green and blue light. In some extreme cases, the individual is unable to see any colour at all.
The most common form of colour blindness causes the individual to mix up the colours red and green. This means that not only do they mix up the two colours, but they confuse anything that incorporates red or green into their makeup. For example, they would confuse the colours blue and purple for each other because they would not be able to see the element of red in the purples make up.
The effects on the deficiency can range from mild, moderate and severe symptoms. For example, 40% of high school leavers are not aware that they are suffering from the condition whereas 60% of sufferers experience problems in their daily life.
There is currently no cure for colour blindness, however there are certain types of filters and contact lenses that may help sufferers distinguish the difference between different colours.