No ippy, you are wrong.
He cannot tell the difference between a pillar box red sock and a obvious laurel green one.
It's not a matter of degrees.
It's not rubbish, he is just an extreme example and according to an optician quite possible.
I've had chance to discuss it, as my son has inherited a more normal and not so extreme version.
My father can see blues.
But he cannot distinguish between red and green at all. ( just varying shades of grey)
My son is more subtle and fails the colour blindness tests.
My father is extreme and unusual. He has often worn one red sock and one green sock and that's why he would ask ( while saying of course he knew, stubborn he is)
The trouble with you ippy, is you are inclined to dismiss everything you have no experience of. Which doesn't make me value your judgements on religion.
No optician ever told me I was talking rubbish when I took my son for eye tests and they asked if colour blindness ran in the family.
I guess, unlike you, they knew what they were talking about.
My father is actually that extremely colour blind. It's rare, but not unheard of.
My Mother and I have lived with it for years.
Apart from putting, "no ippy you're wrong", in your post to me, you have said much the same as I did in that former post of mine, the only difference is you have said much the same as I did using your own words.
What is it?
I get the impression that you don't like to think someone else other than you and yours is completely au fey with how colour blindness works.
I did actually say complete colour blindness is rare and used the word hues instead of shades, you seemed to have missed most of the things I mentioned?
Apart from my slight blue green blindness, no it's not in my family but that hasn't stopped me reading about how we receive and understand colour, I have been a keen photographer for a long time and it's a good thing to know as much as possible about light and how it works in general and I doubt if I'm the only photographer that has taken the bother to learn about how colour works.
I'm sorry that you have this problem in your family but that doesn't make you the only people that know anything about colour blindness.
ippy