What do you know about colour vision?

Sep 4, 2019

We share some insights on the reality of colour blindness in New Zealand


In New Zealand, colour blindness affects about 1 in 12 men, and 1 in 160 women. This means that approximately 4.5% of our population suffers from a colour vision deficiency.

What you might not know about ‘
colour vision deficiency’ is that it doesn’t just refer to seeing the world through a black and white lens – that specific deficiency is actually quite rare.

But common colour blindness is actually much less severe! You can still see in colour, just with restrictions

Although it can sound like a daunting problem, colour blindness is typically easy to live with.

With a little education on colour vision, anyone can learn how to enjoy life while managing colour blindness. In this blog, I will run you through the key things you need to know about colour vision deficiency – from how it’s caused, to how life can be made a little easier while managing it.


Let’s define colour blindness

Did you know it’s actually quite rare for a person to be completely colour blind, and only see in black and white? Most colour vision deficiency occurs between select colours, and only affects a person’s ability to differentiate between the two – not the whole spectrum.

If it’s inherited,
colour vision deficiency will affect both eyes. But if it’s caused by injury or disease it may only be present in one.

colour vision deficiency

This is the most common form of colour vision deficiency, where a person can’t differentiate very well between red and green. This doesn’t necessarily mean they can’t see those colours at all, but they simply have trouble recognising what one is what. This can depend on the lightness and darkness of the colours.


Blue/yellow colour vision deficiency

This deficiency tends to be more severe because people who suffer from a blue/yellow deficiency often suffer from red/green deficiency, too. Often you’ll see neutral or grey tones instead of the colour you’re meant to be seeing.



Seeing no colour at all is the deficiency that you might be associating with colour blindness. Put simply, people suffering from this form of colour vision deficiency won’t recognise any colours at all. It’s very rare, and occurs only in about 1 in 33,000 people.


If you’ve been diagnosed with total colour blindness, it’s important to get professional advice as to how you can make your life easier.

How does a
colour vision deficiency occur?


The first thing to know about colour vision deficiency is that – unless caused by an injury – there is usually no preventing it.

1. Children are born with reduced colour vision

Thanks to genetics, most people who suffer from a limited
colour vision are generally born straight into it. However, men and women inherit the ‘colour blind gene’ in different ways.

In simple terms,
colour vision deficiency is inherited through an X-linked recessive gene. Because of a male’s chromosome structure (X-Y), they only need to inherit the colour blind gene from their mother, while a female’s structure (X-X) requires both parents to be carriers for her to inherit colour blindness.

While there’s nothing we can do about what we’re born with, the good thing to know is that a deficiency
doesn’t hinder any development or get worse with time

2. Deficiency caused by disease or injury

Disease or injury that affects the optic nerve or retina can also be a cause of
colour vision deficiency.

Because some diseases that affect eyesight are progressive, you’ll probably notice a gradual decrease of
colour vision. However, if the disease is treated, eyesight will often improve, too.

Common diseases causing this include:

  • Diabetes 
  • Glaucoma
  • Parkinson’s disease
  • Alzheimer’s disease
  • Leukemia

While genetics and disease are the most common causes of colorblindness, it can also be developed through aging, chemical exposure and some medications.

Tips for dealing with limited colour vision:

While it might be second nature to some who are born with the deficiency, if you’re developing a loss of
colour vision it’s crucial to learn how to deal with the problem.

Here are some useful tips:

1. Focus on order

Simple things like moving through traffic lights really do depend on your recognition of colour. But if you don’t have this ability, the best way you can overcome it is by focusing on their order, instead.

2. Organise and label

If you want a better understanding of the colours around you, labelling and organising household items is a great way to start.

3. Cooking: measure with a thermometer

If you have always measured your food by colour, change your perspective to see how else you can recognise once it is cooked. For example, you could use a thermometer to measure the temperature rather than judging whether it’s ready by how it looks.


If you or your kids are diagnosed with colour blindness – don’t panic! It’s easy to learn how to adapt and go through life without relying on colour, and we’re always here for support.

Concerned about suffering from a colour vision deficiency? We’re always here with expert advice and are your go-to for a friendly eye exam Book an appointment online or phone us on  09 525 1516. 

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