Interesting 'doggie' research has been done at the Vet Dpt of Sydney University.
It explains why some dog breeds chase things & other breeds
prefer to attentively gaze into their owner's face. The 2 types have
2 different patterns of vision cells in their eyes. The pattern in the
'chasers' gives them a wider field of vision. The pattern in the
more 'focused' is bundled in the centre of the eye giving them a
more 'focused' field of vision.

And these patterns match nose lengths...longer nose equals
wide field of vision, shorter nose equals focused vision. In the
program, the first was represented by an Australian Cattle Dog & the
second by a Pug. The first group are hunters & fetchers & chasers while the
second are lap-dogs-house- dogs.

It explained something for me. We'd always had working dog
breeds....Border Collies, Shelties, Blue Heelers (all long noses,
wide fields of vision). Then at a dog show I walked into a line of
Tibetan Spaniels (short noses, focused field of vision). I was
really taken with the Tibbies because, as I told my family, they
'look into your face the same way a person would.' Now I know
they do...& why!

Here's the full transcript of a TV Science Program about this research.

http://www.abc.net.au/catalyst/stories/s953902.htm