I heard that was so that
other humans could see what we were looking at (though dogs may also benefit).
What I did notice was that dog sclerae are more visible than wolf sclerae, and I believe that to be for similar reasons, so a human can read where exactly the dog is looking.
What really blew my mind was learning that the "puppy dog eyes" look was due to extra orbital muscles that dogs have and wolves lack. Dog faces evolved to respond to human sensitivity to facial expressions.