The ancestors of today's cats and dogs were crepuscular — that is, they hunted in the dim light of dawn and dusk, when their prey would also be most active. Therefore, both species evolved to see in dim and changing light. Cats' eyes contain six to eight times more rods than humans, so they only need a sixth to an eighth as much light to see clearly. Dogs can see about half as well at night as cats — still four times better than humans.

The old myth that cats and dogs can only see in black and white is not quite true. Your pet can see some colors, but not others.

Even the most laid back dog or cat can trace its heritage back to some ancient hunter, and your pet's vision is still built to spot scurrying prey — or a fast-moving toy. The same rods that detect dim light also help detect motion, and both cats and dogs have significantly more rods than cones. In terms of how they perceive the world, movement may be the single most important factor to both animals.

Although cats and dogs are great at seeing motion, they are not so great at seeing small details. Dogs see with considerably lower accuracy and clarity compared to humans, and their vision has been compared to that of a middle-aged bifocal wearer, sans glasses. This is not a problem for dogs, because they mostly rely on smell for information about the world.

Same World, Different Views

So, what do cats see? What do dogs see? They see the same world we see with different ranges and depths of color and motion. The next time you look at your pet, take a moment to imagine his view of the world.

What Do Cats See? What Do Dogs See? Science Shows What the World Looks Like to Cats and Dogs

What Do Cats See? What Do Dogs See? Science Shows What the World Looks Like to Cats and Dogs

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