Do you know what Depth of Field (DoF) mean?
I'll give you an example i found on net:
http://keneshablakeney.files.wordpress.com/2011/02/dof1.jpg
As you can see, the first cat, closer to you, is more visible, than the other cat, because you look at it. If you would look at the other cat, the first would be blurry. It would be fantastic if that would be implemented to AoS. What do you think?