If mine are sat in the front window they can spot cars on the road 25m or so away. They can also get spooked by birds flying overhead a lot higher than that. It depends what size object you are talking about; they probably can't spot a cricket from more than 5m or so, but can see larger objects from further away. I have no idea what the clarity is like at any distances though...
I don't know what their field of vision would be like - looking at them I'd guess that they can't see behind them like rabbits can (their eyes don't protrude far enough). I've also got doubts about whether or not they can see something right in front of their noses; if they can it would only be with the periphery; they wouldn't be able to move their eyes enough to focus the image. It may be a similar shape to that of a whale - ie a triangle either side of the head that don't overlap at the front nor the rear. I've never seen a study published about it or anything though, so wouldn't like to say for certain. Considering their side-mounted, side-facing eyes, they do a pretty good job on judging distances when hunting!