What is Colourblindness?

Colourblindness is a disability that changes how people perceive colour. As a colourblind web designer it was interesting to begin learning what this means not only for myself but for other people too.

Who is affected?

allaboutvision.com have an article on colourblindness which charts how the condition affects males and in which ethnicities.

As you can see from this chart, colourblindness affects mainly caucasian males, and African American males are affected the least. Note that this was an american study so there are some ethnicities that might be missing here, but it gives a general idea.

How can I find out if I am colourblind?

There are a range of tests that can determine how colourblind you are, but the one I trust most is the Isihara test. The best one of these that I have found online is on the Enchroma website. The test displays a number inside a circle of coloured dots, and depending on what type of colourblindness you have, and indeed if you are colourblind at all, you may well see different numbers, or no number at all in some circumstances.

A good example is the plate below provided by colorvisiontesting.com. What number do you see here?

If you have normal colour vision, you should see a number 5 (apparently?). Because I am colourblind I don’t see a number here at all, just a range of orange, yellow, green and red dots.

What is the cause of Colourblindness?

Colourblindness can be caused by a hereditary gene defect. Most commonly an X-linked recessive gene defect can cause red-green colourblindness. (allaboutvision.com)

To be colourblind because of an X-linked recessive gene defect your Mother must also be a carrier or be colourblind herself.

That said, colourblindness is not always hereditary and a person can gain colourblindness later in life through aging, Eye problems (such as Glaucoma, Macular Degeneration, Cataracts or Diabetic retinopathy), injury to the eye or it can also be caused by side effects to some medications. (Webmd.com).

Solutions to Colourblindness

There is no real medical treatment that can cure colourblindness if it is hereditary. However, Enchroma have released glasses in the last few years that are said to restore colour for some colourblind people. You can see the reaction to the glasses by one person below:

There are many of these videos online and whether they are true reactions or set ups I am not sure. Some people on the other side of the argument on Enchroma say that the glasses are not as effective as some videos show. I would love to be able to try them to give my own verdict at some stage in the future.

This is the only real resolution to colourblindness currently so they might be worth a try if your colourblindness is causing you real issues.

How can I see what Colourblind people see?

If you are not colourblind you might still want to see what colourblind people see.

There are browser extensions for this online such as this Google Chrome extension from artbek,. Whether this is what other colourblind people see, I am not sure, but it feels like a good base for some simple testing on websites.

For an interesting post on designing for (and with) colourblindness, please see this post by Aaron Tenburen: Link