Thread:Paul.rea/@comment-11835613-20130823141113/@comment-11533671-20130824175344

Had to chime in here because I am a huge lover of dogs! Dogs and other animals being "color-blind" is about the same as saying a human is "color-blind". Here is the actual science behind their vision from the AKC (American Kennel Club):

Dogs are not color blind - they see color, but their chromatic acuity is significantly less than humans'. This is for two reasons: (1) dogs have far fewer cone cells in their retina (cone cells are responsible for seeing color); and (2) dogs are dichromatic (they see only two primary colors - blue and yellow) whereas humans are trichromatic, meaning we see three primary colors - red, blue, and yellow.

Humans have 7 times higher proportion of cone cells than dogs, meaning that when dogs do see colors, they are pale or faded. However dogs have a much higher concentration of rod cells, which are responsible for seeing black-and-white, and also much more sensitive in lower light conditions. For that reason, dogs have much better night vision than people.