Which isn't to say that dogs don't literally see you — their eyes are another form of input, just not the primary one. "They might look at someone with their eyes; as you approach, they look at you," Horowitz said. "But then once they've noticed that there's something with their eyes, they use smell to tell that it's you. So they sort of reverse that very familiar use of ours."
And that's crucial to understanding how dogs see the world.
You, as a human, might smell something delicious and then use your eyes to look around to locate the source of that delicious smell. "Ah, it's pasta sauce slowly coming together on a stove!"
For dogs, the opposite is true. Or, as Horowitz put it:
"We smell something and then when we see it we're like, 'Oh yeah, that's it. That's what it was. It was cinnamon buns.' And dogs when they see you, they're like, 'Okay, that's something to explore, I'm gonna smell it. Oh yeah that's Ben.'"