Roses are gray, violets are gray.
That’s how most people believe dogs perceive the world. Because, as everyone assumes, dogs are color blind, right? Cats too… or so they say…
But that’s just not so! They’re absolutely not color blind. Not in the way you might think anyway. Thing is, their vision is fundamentally different from ours. To be sure, dogs see colors, but in dogs, the range of these colors is restricted to those in the yellow portion of the spectrum. They have a harder time distinguishing between red, yellow, green, and orange (albeit better in bright light). And they’re less likely to discriminate between hues of grays.
For cats, there’s a debate as to whether blues and grays are the norm, or whether it’s the same yellow-based spectrum dogs see, just with less saturation and richness of color.
Here’s how it works:
All mammals have rods and cones in their retinas (the light sensing lining of the back of our eyes). The rod cells are more sensitive to movement whereas the cones are more sensitive to light. Humans have more cones than dogs and cats, which is how we can detect a broader range of the light spectrum. (Though this is an oversimplification, of course.)
But here’s the thing: Pets don’t need to see as many colors. After all, they’re hunters who are primarily carnivorous. They don’t need to worry so much about mistaking one kind of edible plant for another, for example. As predators, they’re much more concerned about being able to see their prey move on a landscape or in a forest. Contrast is everything.
That’s where those rod cells come in. With more rods, they can perceive objects in the dark better, whether they’re moving or not. Add that feature to the reflective coating in the back of the eye, which amplifies the available light, and you have a recipe for excellent low-light vision –– something every nocturnal predator needs.
What’s more, cats, in particular, have a greater range of vision. Their globe-like eyes see a two-hundred degree range whereas ours only see 180.
Humans do best pets in the visual acuity arena, however. We can see stationary or slow-moving objects more crisply at a wider array of distances. Which only makes sense. We’re slow and omnivorous, after all.
So next time you hear someone proclaim that dogs don’t care whether their ball is yellow or blue, you can tell them that dogs actually might prefer a yellow one since it probably pops more. And yes, your cat probably does prefer the bright red laser pointer to the little mousey things littering your floor. They do see. And they do care.