how do people know dogs can only see in black and white?

Question

cause i was told that years ago and always wondered

Answer 1

It is not true that dogs are completely colour blind. While dogs do not have the same color vision as humans, they are able to tell yellow from blue. Like a human with red-green colour blindness, they are unable to tell the difference between red and green.

The reason for this limited range, in both the colour blind human and the dog, is that there are only two kinds of colour receptors in the retinas of their eyes. While most humans have three kinds of colour cells, with three different receptor molecules sensitive to blue, greenish-yellow, and red, dogs only have receptors for yellow and greenish-blue.

Canine eyes also lack another human trait: the fovea, an area especially dense with detail-sensing cells. As a result, their detail vision is not as good as ours. But they make up for this by having much better night vision and greater sensitivity to movement.

Answer 2

They have apparently changed their minds about this and decided some dogs can see in colour! What I'd like to know is how do they know that 1 human year = 7 dog years? Although I believe their is a new formula for this now as well?

Answer 3

Dissection. Dogs can see some colour, it was originally thought they could see only monochrome.
You have cells in the retina of your eye called rods and cones. One of them sees colour; dogs have fewer than you do.
You can mimic the effect by wearing orange glasses; your depth perception improves and you'll notice movement better. These are advantages to a predator.

Answer 4

It's actually not true. Dogs (like most mammals except some primates, including us) only have two types of cones in their retinas, which means that their colour vision can distinguish far fewer distinct colours. Humans, chimps, and some monkeys have three types of cones, so our colour vision is better. Birds have four types, and can probably distinguish colours that would look identical to us.

Answer 5

It hasn't been completely proven I for one do not believe this I've seen dogs trained to put there paw on the color they say and they even mix the color card around.

Well we have a Great Dane that stays at w/ us at the kennel and when other dogs of his color come in he seems more interested in those dogs like we let him roam around one time and he seen this little pug of his color and he was very interested this has happened w/ other dogs too.

Answer 6

I am 65. and in all my years of owning dogs, I have wondered at this question. I am of the notion that dogs come in all different sizes,shapes,coloures, breeds and sizes...........yet for all this they are all wonderful ! some of your answers are reasonable but the question still remains ............we are not dogs .........we are supposed to be at the top of the animal kingdom........but until we are re-incarnated as a dog, a dog that has amongst other things the"knowledge of how to use a computer etc." to enable it to answer this question, I as a mere human would prefer to beleive that it can see colours.........................

Answer 7

they test them, try to train them using colors... also, we have things in our eyes that help us see colors, and other things that help us see black and white. Dogs only have the things that help them see black and white. haha I know "things" isn't very technical but I don't remember what they are called.

Answer 8

I don't know personally i think "The experts" are full of S**T but my Stafford-shire Bull Terrior was black & white & he was always happy...!

Answer 9

Their eyes don't have the rods and cones required for seeing color. Students have performed experiments for projects, too:

Answer 10

this is a myth.dogs have both rods and cones in their eyes,but not as much as humans.they do see color,but not as vividly as we do.