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Colour Blindness

When you hear the term colour blindness, you may naturally picture only seeing the world in black and white. Many people don't entirely understand what colour blindness is, that there is a spectrum of colour blindness, and there is a way to work with it. We'd like to give a rundown of the basics of colour blindness, what it entails, and what can be done for it.

Colour Vision Chart

What is Colour Blindness?

We often hear it referred to as "colour blindness," though true in the sense that some people are unable to see a colour or two altogether, that's not all that the condition entails. Its better name is Colour Vision Deficiency (CVD) because there are things that can happen to our vision to cause lack or change in perception of colour from most people. It can be caused by a mutation in the genes that make up your cones (that are red, blue, or green) which distinguish colour vision, and being a genetic condition makes it hereditary and linked with the X chromosome, so these types often affect males. Some colour blind people can also acquire CVD through other disorders that affect the retina and the brain, through exposure to harsh chemicals and drug intake, or other conditions such as glaucoma, macular degeneration, diabetes, or multiple sclerosis.

Types of Colour Blindness

  • Red-Green CVD

    • Deuteranomaly is when the green cone photo pigment is abnormal, making the colours green and yellow appear more red, and it becomes almost indistinguishable to see the difference between violet and blue.

    • Deuteranopia is when green cone cells aren't working, making green more like beige and red a brown/yellow colour.

    • Protanomaly is when the red cone photo pigment is abnormal, making warm colours appear more green, and colours overall are not very bright.

    • Protanopia is when red cone cells aren't working, making red appear black, and orange, yellow, and green all look yellow.

  • Blue-Yellow CVD

    • Tritanomaly is when there is a small amount of blue cone cells, making it nearly indistinguishable to see the difference of yellow or red from pink. This CVD is very rare and can happen to males and females just as equally.

    • Tritanopia is when there are no blue cone cells, making blue look like green, and yellow and can appear as violet or gray. This is also very rare and can happen to males and females just as equally.

  • Total CVD

    • Achromatopsia (or Rod Monochromacy) is what everyone immediately assumes of people with colour blindness, though it is actually very rare to have. All the cone cells are lacking photo pigments, seeing everything in black, white, and gray.

    • Cone Monochromacy (Red, Blue, or Green) is when two out of the three cone cell photo pigments aren't working. Since people with this CVD only have one set of cone cell photo pigments to base colours on, it becomes essentially impossible to discern colours as there's nothing to compare them.

Colour Vision Chart

EnChroma Colour Blind Test

The EnChroma Colour Blind Test measures your ability to distinguish shapes, numbers, and letters based on the different colours of dots that are closed in on each other. If you aren't able to discern what's happening in the image, then you're probably colour blind. You can take the test yourself right here.

Nvision Eyecare and EnChroma Glasses

There is such a thing as EnChroma eyewear that filters out wavelengths of light right where there may be some kind of conflict with the way your eyes are perceiving colour, then increase the distinction between red and green, making your view of the world a little more colourful.

Nvision Eyecare is the only authorized retailer for these glasses in New Zealand, located in Albany, Auckland. One of our specialties is colour vision, and we have a colour blind test here, and if you have questions about your colour vision or would like to arrange a consultation and speak with one of our experienced and professional optometrists, please visit us here.