I have found a couple cites with information about visual acuity and comparing the colors we see as opposed to dogs, but most of them are a little technical for me. My question is this.
How much if any do dogs see outside of our normal visual spectrum? For example can they see further in to IR or UV bands than we do?
I do not believe they can see further outside the visual spectrum than humans can. Dogs have dichromatic vision meaning they see two colors instead of three like humans do. Best guess is they cannot see red-green in the visual spectrum but see yellow-blue.
Dogs do however have better low light vision than humans do. They are not an infrared camera…they are just more sensitive to light so see better when there is not much to be had. They detect motion better than a human does as well although they are somewhat nearsighted compared to humans (I have read about 20/75 vision…I think cats are even more nearsighted than that).
Color discrimination is not the same thing as spectral range. A creature with no cones at all could still detect light within some range; it just wouldn’t be able to tell the difference between light at the high-frequency end of the range and light at the low-frequency end.
While color discrimination varies among animals (humans are among the best, as mammals go), I don’t think that spectral range does all that much. The spectral range of vertibrate eyes is mostly limited by fundamental physical limitations like the transparency of water. Insects can see into the ultraviolet, but their eyes are constructed entirely differently than ours. And some snakes can detect infrared, but the organs used to do so are even less like eyes, and probably can’t be said to actually “see”.