A dog’s smell is more than 100,000 times stronger than that of a human’s, which they need because their eyesight is not as keen as a human’s. But, dogs’ sense of hearing is greater than ten times more acute than a human’s. Humans can detect sounds at 20,000 cycles per second, while dogs can sense frequencies of 30,000 cycles per second.
But, it is a myth that dogs are color blind. They can actually see in color, just not as vividly as humans. It is akin to our vision at dusk. Dogs DO have better low-light vision than humans because of a special light-reflecting layer behind their retinas.