A question about colour blindness...

[Ron Obvious]

The most common form of colour blindness is the inability to distinguish red and green. When I first heard about this condition in school, I asked if people with this condition see both colours as what we call 'red', what we call 'green', or something else entirely. Obviously you can't ask them -- how would they know?

At age 10, I stumped my teacher with that question. I just realised that I'm now comfortably in middle age and I still don't know the answer.

Anyone?

[tk2kewl]

1. it varies

i have some colorblidness and it would be more aptly termed color confusion if you ask me. sometimes red looks green or green looks red - blue looks purple or purple looks blue - brown/green same deal.

my brain decides what it must be, i am just wrong sometimes

[Ron Obvious]

4. Thanks

Interesting. So it sounds like it's more like mishearing or misreading a word. You don't consciously guess at it, you really heard or read it that way.

More confirmation that we see, hear, smell, feel, and taste with our brains, not the respective senses.

[hlthe2b]

2. Here's a post I made re: canine color "blindness" which is not unlike the most common form of human

http://www.democraticunderground.com/1018295577

It might help answer your questions.

[Ron Obvious]

6. Very informative

Somehow I missed that back then. Thanks!

[Sekhmets Daughter]

3. My ex could not distinguish blue from green...

both looked blue to him....

[Ron Obvious]

7. But how did he know?

But how did he know what blue was supposed to look like? Only by accepting what someone else told him when they pointed at something blue, right?

I recently heard a fascinating study on the radio that the ability to distinguish the colour blue is very recent in human development. As proof, the authors cited that the colour is virtually never mentioned in ancient literature as compared to all other colours and that there was no blue in the natural environment of the authors. Now you might immediately object, as I did, and say that the sky and the sea are blue, but those are described as green in ancient literature.

[Sekhmets Daughter]

13. The same way you know what blue is supposed to look like...'blue' is,...

after all just a word we ascribe to a certain color. The ancients may have seen little difference between blue and green or they might not have considered the difference great enough to assign a separate word to what they viewed as a shade. Particularly if there was no blue in the natural environment of the ancient authors...how would they 'know' it existed, yet alone need a separate word to describe it?

It's an interesting idea to consider. For the most part, I've seen blue skies and green seas. Here in FL, where the Gulf Stream is closest to the shore, you'll see when you enter it because the water looks bluer. But the only place I've ever seen really blue water right at the shoreline was Morocco.

I find the idea than humans couldn't distinguish between the sky and palm fronds, but had developed writing, a bit difficult to accept. Had they said the earliest humans couldn't differentiate between blue and green until after they discovered fire, I'd have less difficulty getting my head around it.

[Ron Obvious]

19. But we can't compare notes

Since we can't look through each other's eyes, we don't know if the colour he referred to as 'blue' is the same colour we refer to as blue. Obviously he thinks it's blue because that's what he's always called blue.

Ultimately, it is a philosophy question as mentioned down-thread.

I don't know if the theory that being able to distinguish blue is very recent has merit, but I found it fascinating in how radical the notion it is. The authors claim that the ability to synthesise blue dyes is a very recent development, as is the mutation that causes blue eyes, and that originated in more northern latitudes were the people were illiterate. Still, the numbers are interesting. Apparently blue just isn't or rarely mentioned in the Bible, in Homer or in other Greek and Roman literature of the day.

[Sekhmets Daughter]

22. Sure you can

Put out swatches of color to be identified...what you won't know is the shade or tint perception

[Ron Obvious]

25. Still...

Sure, the colour blind person will identify that colour as blue, because that's what blue has always looked like to him and what he's been told is blue since childhood. "Blue" is just a word we use for light in a certain frequency range after all.

But that doesn't mean we would call it blue and neither could we be ever be certain we see the same thing or that, say, Brussels Sprouts taste the same to me as to you.

[Sekhmets Daughter]

27. If you like Brussel Sprouts, I can assure you they don't tast the same to us!

That's an excellent analogy ... there is so much variation in our senses of taste and smell, why not sight as well? I know that my ex didn't perceive shades of blue well and I didn't remember until later, that purple gave him a lot of trouble as well.

Thanks for a really interesting thread!

[In_The_Wind]

12. You must have gotten some lovely gifts from him.

imo: blues and greens blend well together.

[Sekhmets Daughter]

14. Purple caused him problems as well!

Lovely pair of a truly horrendous shade of purple pants once. Jewelry was the ticket...

[In_The_Wind]

15. no body is perfect

[Sekhmets Daughter]

16. That's for sure!

[In_The_Wind]

17. Have you seen:

"Rabrrrrrr moved Match Game to Sunday"

[OriginalGeek]

5. My uncle has red/green color blindness

His Christmas decorations are whack.

[Ron Obvious]

8. No doubt!

Ha, no doubt! Since we culturally use red to signify "danger" and green as "safe", I wonder what that does to the psychology of those who can't distinguish those colours. Are they more risk-averse than the rest of us, or just the opposite?

[OriginalGeek]

9. I don't think he's a very takey chancey kind of guy

he's in his mid 80s and still very active and alert and fun to be around but I think he got there by being pretty conservative in his adventuring. My aunt makes sure he dresses right and eats right but everything else is done in his own calm, mild-mannered way. I believe he developed a very keen wit to compensate for lack of daredevilling.* He makes me laugh uncontrollably at times.



*They have traveled the world, however, so that is pretty adventurous. A couple years ago they went to Jerusalem and visited the holy sites there and that's something I wouldn't do right now. I'd be scared to death of getting blown up.

I've never seen him raise his voice in anger or fly off the handle about anything - and when we (my cousins and I) were kids I spent a goodly amount of time with them and we got up to some shenanigans.

Now that I remember though, that might have been because he let my aunt handle all the hollering.

[RebelOne]

10. An aunt (now deceased) was color blind,

but I think she also had a problem with patterns. She would wear stripes and plaids together.

[talkingmime]

11. About 95% (or so) are red/green. The remainder are blue/yellow. I'm not aware of grayscale. BUT...

I just had a conversation with my mom this morning (coincidence) about the issue. Color blindness is passed down genetically from the male but only if his mother got the recessive gene from her father. So basically, if you're color blind in either way, your mother gave you the gene that caused the condition and she received it from her father whether or not he exhibited the condition. It's a weird dynamic because a color-blind male can't pass it on to his son, only through his daughter. By the way, dogs can see color, but only the blue/yellow part. Throwing a red ball into a green lawn is sort of cruel if you think about it.

For a while, certain municipalities experimented with horizontal traffic lights, mostly because they didn't involve hanging fixtures. It was a major problem because red/green color blind people couldn't distinguish one signal from the other unless it was yellow. Every one of those I know of has been replaced with vertical lights. And the red lights with the flashing white "strobe" are intentionally on a variable flash to avoid epileptic seizures. Sometimes it takes a while, but they eventually figure that stuff out.

[Ron Obvious]

20. Horizontal lights...

I'm not the most obervant person around, but I thought horizontal traffic lights were still very common. At least, I'm pretty sure they are here in the Pacific Northwest.

I'll make sure to pay attention next time I leave the house!

[Callmecrazy]

23. Pretty common in South Florida.

[surrealAmerican]

18. Even without color blindness ...

... you can never be sure how anybody else perceives color. It's a philosophical question at its core: if what I see as red looks the same to me as what you see as red looks to you. Just because we have similar physical structures to sense something doesn't mean our experience is similar.
We take this for granted with other senses: I may love the smell of seaweed, but to you it smells bad - even though our noses work the same way.

[Ron Obvious]

21. Philosophical question.

You're right; it is in a sense a question of philosophy. Our brain constructs our reality for us from the data provided by our senses.

I'm sure that in the near future we will be able to record all our sensory input like in the obscure movie Strange Days, and then play them back later for a full immersion experience. It would certainly be interesting to immerse in somebody else's reality.

[lastlib]

24. This may help you:

http://www.colblindor.com/2007/04/17/deuteranopia-red-green-color-blindness/

[Ron Obvious]

26. That did help

Thanks, that was very interesting. I didn't even know there were subtypes before.

Imagine living in a world of pastels, blues, and greys...