What kind of tests did they give the dog? Since a dog cannot answer empirical questions about its eyesight, where did science come up with the fact that a dog cannot see colors?
If this is true, does a dog see in black and white?
Concerning humans, do color blind people see in black and white? I (as well as everyone else) have taken the colorblind test, which is a card with bubbles and inside the bubble is a number. Why have this test? Wouldn’t a color blind person know they are color blind? If you are born color blind and someone told them to give me the red toy, wouldn’t they tell you that they don’t know what red is, except in objects where they were told were that color, with the born color blind person not having a concept of what red is? If someone becomes colorblind, after a time, wouldn’t they know what was happening to them? I have never heard of a case of someone losing the ability to know color, but I am sure that this has happened before.
There was a recent movie called “Little Miss Sunshine.” One character was the older brother (or half brother?) of the little girl. Make a long story short, the family makes a journey from New Mexico to California, with the mother’s brother in tow. Taking a test driving, the Uncle of the boy tells him that he is color blind from a test, and because of this, he has to forfeit his dream of being a pilot. The kid screams in agony hearing the awful news. Again, wouldn’t an 18 year old boy figure out that he was color blind beforehand.
Dogs and color blindness, or in more general terms, what is color blindness?
Some animal tests involve training animals to find food behind a door or inside a box on the basis of the color of the door or box. When they find a pair of colors we think are different that the animal doesn’t distinguish when looking for food, they conclude it’s because the animal can’t distinguish them.
Helpful visual spectrums for comparison. A red ball then is apparently the wrong color to get, tho blue will work. Note that even for the colors they can see, they’re more washed out than they are for us.
No, dogs are red-green color blind. Their eyes only have two cone types instead of three, which means they can’t see the colors red or green. Here’s Cecil with more.
In terms of people, most color blind people don’t actually see in black and white.Most people with color blindness have deuteranomaly, which in practice, means they usually have trouble seeing the color green.
Here’s a fun little app if you want to see what things look like to people with various types of color blindness:
There are cases where people cannot see colors at all - everything is some shade of gray - but those are pretty rare. Most color blind people can see colors but different colors look the same. The most common case is where red and green both look like shades of brown.
As for not knowing you’re color blind, what would you be comparing it too? Stop signs would always have looked brown to you - how would you know what they look like to other people? The only way you would figure it out is when you notice that other people are distinguishing between colors that you can’t. And how often does that come up in normal conversation?
I am color-blind. I can still differentiate colors, but not as many shades of each as someone who is not.
I am a pilot. The original reasoning for banning the CB from flying is because at some control towers, or those whose radio has failed, pattern and landing instructions are given to pilots by flashing red, green, or white lights. I had to go stand on the runway with my FAA guy and tell him what color lights I see in the tower.
I cannot hold an ATP rating, or fly for the military, but I could get a commercial rating.
Wikipedia has some good informationabout the condition. I can’t see most of the numbers in the “bubble circles”.
For many colorblind people you would never know except for those dot tests.
For the most part I can tell you what color anything is, but where I have trouble is differentiating between “muddy” colors.
Pure red and pure green do not look alike for me, but reddish-brown, brown, and greenish-brown are all the same.
In the real world there are only limited contexts where this matters. Off the top of my head:
[ul]
[li]Putting together an outfit where the pants are a color other than blue. I avoid this ;)[/li]
[li]Some geographical maps and other diagrams are color-coded using shades of brown and are impossible to read. This is less common today due to greater awareness of color blindness.[/li]
[li]Some electronic components are identified only using color coded stripes. This is only an issue if you are a hobbyist or electronics engineer, but a major pain if you are.[/li]
[/ul]
You can tell by the structure of their eyes. The retina of your eye contains photoreceptors called rods and cones, which are named that because that’s what they physically look like under a microscope. The rods are used for black and white vision, low light vision, and to detect movement. The cones are used to detect colors. Humans typically have 3 types of cones. As previously mentioned, dogs have only two, and the one they are missing indicates that they are basically red-green colorblind.
Furthermore, dogs have fewer cones and more rods than humans do, which means that even with the colors that they can see, they can’t see them as well as we can. They also have better low light vision than we do, and can detect movement better than we can. Dogs also have reflective cells behind the retina which give them even better vision in low light. We don’t have that structure so it is difficult for us to imagine what it looks like to be able to see with it.
Cecil’s article mentions training them with colored containers to find food. It has also been noticed that a dog can chase an orange frisbee or tennis ball with no problem while it is moving, but if it stops in grass the dog has a very difficult time finding it. The dog obviously has difficulty distinguishing between orange and green.
What is interesting in Cecil’s article is that it mentions that cats have the structures to see colors in their eyes, but they don’t necessarily do anything with that information. It is very difficult to train cats to distinguish something based on color, so difficult that for many years it was thought that cats were colorblind.
Not necessarily. I have known people that didn’t figure out they were colorblind until they were in their mid twenties. One guy was working on some electrical wiring, and the guy he was working with told him to hand him the red wire. Instead, the guy handed him the green wire. The guy he was working with him said no, I said the red one, and the guy said that is the red one. So he thought he could see colors, but he couldn’t.
So why don’t they suspect that something’s up when they open the box of crayons and notice that the crayon labeled “green” looks the same as the crayon labeled “red” or “brown”?
a) They may not have paid that much attention to it.
b) Some crayons are quite similar, and without being told so, a red-green colorblind person wouldn’t know the red and green crayons are supposed to be radically different. They won’t be the exact same unless they share the excite the color receptors the person does have in the exact same way.
In my case, my color blindness is mild enough that I can usually differentiate between colors, but I don’t see nearly as much contrast between certain shades as a non-colorblind person can. Like some of the guys above, if it weren’t for the charts, I probably wouldn’t know I’m colorblind. Reds I have very little problem with, but there are some shades of green that look a lot more brownish to me than they do to everyone else. I’m not completely “green blind,” but rather “green weak,” or deuteranomaly. This milder form is the form most colorblind people have, about 6% in males.
Incidentally, can any of the non-colorblind people here see the word on this page’s Reverse color blindness test? (scroll down to middle)
In the first link, I was able to read the reverse test with some effort, and all the rest easily. In the second link, I got the first one, but not the second one until after I’d seen the answer (but then could see it).
AFAIK, I have full color vision because I can always pass the various colorblind tests. Anyway, my guess was way off, and even knowing what I’m looking for, I only kind of see it.
I can see the first one, but I think I also have particularly good luminosity; I did have some trouble with the upper part, but the bottom is fairly clear. The second one I had a vauge idea of what it might have been, but it’s not hard to see when I know what to look for.
Anyway, as others have said, there’s all different kinds of color blind, it all depends on exactly how light stimulates the various cones. Some Red-Green people can tell some shades apart quite easily, but have considerable difficulty with others.
And, really, of the people I know that have some type of color-blindness, they really didn’t know until they identified something by an incorrect color and it was pointed out. I think my brother caught onto it when he’d identify some things as brown that were clearly green to most other people. I also used to have a friend who was almost completely colorblind, but he’d known his whole life since, well, it’s hard to get through early school and not be able to identify colors.
Interesting - I was able to see all three of the reverse colorblind tests right away. Kind of nice to finally be able to see something after a lifetime of being told to look for invisible numbers in baffling color charts.
