People with colour vision deficiency are unable to see colours the same way that most people do. They may find it difficult to distinguish between two different colours.
Colour vision deficiency is often referred to as colour blindness. However, true colour blindness is where no colour can be seen at all, which is rare.
People with colour vision deficiency may have difficulty identifying pale colours or deep colours if the lighting is poor.
Colour vision deficiency can vary in severity. Some people will only experience a very slight difference in the way that they appreciate different hues and shades of colour. For others, many colours will all appear to be the same.
Read more about the symptoms of colour deficiency.
Types of colour vision deficiency
There are three main types of colour vision deficiency:
- red-green deficiency (deuteranopia) - this is the most commonly diagnosed type in which people are unable to distinguish certain shades of red and green
- blue-yellow deficiency (tritanopia) - this is a rare condition where it is difficult to distinguish between blue and green; yellow may appear as a pale grey or purple
- total colour blindness (achromatopsia) - this is the rarest type of colour vision deficiency; it is where no colours can be detected and everything appears in shades of black, white and grey; people with this condition have poor sight and are very sensitive to light
What causes colour vision deficiency?
In most cases, colour vision deficiency is an inherited condition (passed on from your parents). However, it can also sometimes develop as a result of a pre-existing health condition or as a side effect of a medicine.
Colour vision deficiency occurs when the cells in the retina that interpret colour do not function properly. The retina is the thin layer of nerve cells that line the inside of the back of the eye.
Read more about the causes of colour vision deficiency.
Diagnosing colour vision deficiency
Many people first become aware that they have a colour vision deficiency when they have a problem identifying colours correctly.
For example, a child may have difficulty naming colours or you may struggle to read a map or a document.
It is important to identify a colour vision early. If your child is diagnosed at an early age, it will help with their learning at school.
Read more about diagnosing colour vision deficiency.
Treating colour vision deficiency
There is currently no cure for inherited colour vision deficiency because it is not possible to repair or replace the faulty nerve cells in the retina.
However, as colour vision deficiency does not cause any long-term health problems, treatment is not essential for you to be able to lead a normal, healthy life.
If you have colour vision deficiency as a result of a pre-existing health condition, or by taking a certain type of medication, it may be possible to improve your symptoms either by treating the underlying condition or by using an alternative medication.
Most people with colour vision deficiency learn to adapt to their condition, and it is usually possible to find ways to compensate for your difficulty with colours. For example, it is possible to recognise the position of the lights on a traffic light, rather than the different colours.
Read more about treating colour vision deficiency.
Complications of colour vision deficiency
Although having colour vision deficiency will not affect your long-term health, it could affect your career choice.
This is because certain jobs, such as pilots and air traffic controllers, require accurate colour recognition.
If your child has colour vision deficiency, they may struggle at school unless the teacher is made aware of the problem.
Many learning materials are colour coded and your child may find it more difficult if their learning environment is not adapted to their specific needs.
Read more about the complications of colour vision deficiency.
