The sights used by the US Military have a much broader field of view and better illumination than most of us are willing to afford. Additionally, most of the time they fight at greater distance than an individual or family is likely to be forced into.
If you can hit a chest-sized target while standing at 100m, you have 99% of your combat scenarios handled.
...and you have the other 1 percent handled if you can get them before shooting back at you ;O)