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Colour Vision

Colour Vision Chart

The world is flooded with color, in more shades than is possible to name. Many of us take the ability to enjoy the glorious technicolour that our environment has to offer for granted. However, approximately one in 12 men and one in 200 women find struggle with their colour vision and instead have a very different view of what is going on around them.

Colour vision is the ability to distinguish specific shades of color. Those patients who lack this ability are often referred to as having colour vision deficiency or as being ‘colour blind’. Despite this name, the inability to see any color at all (a condition known as achromatopsia) is very rare. Instead, someone who has color vision deficiency will find it difficult or impossible to differentiate between certain colors.

Here at NVISION Eyecare®, our expert team have the knowledge and understanding of colour vision deficiency to both diagnose and help you to manage your condition so that you can still enjoy life to the fullest.

What colours can’t people with colour vision deficiency see?

The vast majority of patients with colour vision deficiency struggle to distinguish between shades of red and green. However, some patients also find it hard to tell the difference between shades of blue and yellow. Many people think that this difficulty in telling the difference between these shades means that they mix them up. In fact, what colour vision deficiency means is that the sufferer mixes up all colours that have some element of red or green, or blue or yellow, as part of the whole colour. For example, someone who has red/green colour vision deficiency will mix up a blue pen and a purple pen because they are unable to see the red element that turns blue into purple.

If you were to take a standard box containing 24 coloured pencils, someone with a red/green colour vision deficiency would only be able to identify around 5 of them correctly. Some patients may be able to see the colours, but they would appear much duller than they would to someone with normal vision.

Exactly how severely someone is affected can vary tremendously between patients. However, many patients go through life without ever having their colour vision deficiency detected because, as they are used to their vision, they simply don’t realise that there is anything wrong with what they are seeing.

What causes colour vision deficiency?

In the majority of cases, colour vision deficiency is a genetic condition, meaning that if you suffer from this problem, you are likely to pass it down to any offspring that you have. Nevertheless, since it is the X chromosome that carries the gene, men are more likely to be affected than women. If you have inherited colour vision deficiency, the severity of your condition should remain steady for the duration of your lifetime.

It is possible to become colour blind later in life. If this happens, it is most often caused by having a long-standing condition such as diabetes, liver disease, multiple sclerosis, Alzheimer’s or Parkinson’s disease. It can also be caused by eye diseases including glaucoma and macular degeneration. In this instance, it is possible for the degree of your colour vision impairment to change over time.

Diagnosing colour vision deficiency

Fortunately, a colour vision test is a fairly straightforward procedure and something that we can carry out for you here in our modern, comfortable practice. Diagnosis involves a comprehensive eye examination during which you will be shown a series of pictures composed of coloured dots. These are known as pseudoisochromatic plates. You will be asked to look for numbers amongst the various coloured dots. If you can see these clearly, you are unlikely to have colour vision deficiency. However, if you cannot see them or if you see an incorrect number, you may be colour blind.
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Can colour vision deficiency be treated?

Whether or not your colour vision deficiency can be treated will depend on what is causing it. If you have a medical complaint that has caused you to become colour blind, treating the underlying cause successfully can help alleviate your symptoms.

Unfortunately, if your colour vision impairment is genetic then there is no cure. Nevertheless, there are some things that may be able to help you manage your condition. Some people find that wearing special tinted glasses or wearing a red-tinted contact lens in one eye can improve their ability to differentiate between colours. Others find ways to work around the impairment, such as by labelling things of colour or remembering the order in which colours are likely to appear – for example, the order of a traffic light with red on top, amber in the middle and green on the bottom.

If you have questions about your colour vision, or if you would like to arrange a consultation with one of our experienced and professional optometrists, please do not hesitate to contact our practice today.