If you met someone who had a colour vision deficiency what would be the first question you’d ask?
Would you point at something and say “What colour is that?”
If so you are not alone. That is the first thing everyone asks and people with colour vision deficiencies hate it. They hate the “what colour is this? what colour is that?” game
If you ask them what colour a red delicious apple is, they know the “right” answer is “red” – even if it looks more like grey to them. They know traffic lights have red at the top and green on the bottom, and that their favourite “blue” shirt is purple to the rest of us.
As we have mentioned in previous Blogs, they teach themselves to know what different colours are because they have been taught over their lives.
The majority of people think that people who can’t see colours properly only see in black and white, which is not correct. They can see colour, but there are different types of colour vision.
People who have mild colour vision defects have anomalous trichromacy, which means that they do have all three types of cones, but one of the cones is defective. Someone with deuteranomaly, the least severe kind of colour-blindness and also the most common, has unusual red cones, while someone with protanomaly has unusual green. People with deuteranomolous vision may not even know they don’t see colours normally. Tritanomaly, trouble distinguishing blue and yellow, is quite rare.
People who are missing one type of cone altogether have dichromatic vision, which is more serious than anomalous trichromacy. Within this category of dichromatic vision, we have three different types.
Deuteranopia: no green cones (also referred to as L cones, as insensitivity to long wavelengths of light)
Protanopia: no red cones (M or medium wavelength cones)
Tritanopia: no blue cones (S or short wavelength cones)
So when you meet someone who is colour-blind, colour deficient/ iRochromatic – Don’t ask them to tell you what colour their shirt is. They know what colour their shirt is!
And keep in mind that this has happened about a million times in their lives and they may not find it as hilarious as you do and if they get the colour wrong, just correct them.