I see this in Options under display. What does this mean. I have played with it off and on,

And don't see any difference.

http://www.gamesas.com/topic/1574144-recon-scope-vs-regular-scope/

It will show you markers to your quest destination. They will be floating over doors if you're supposed to pass through it, and will appear on your compass. This option also toggles the recon scope markers, so beware that little tidbit if you use a recon scope.

http://abload.de/img/3wlps6.png

the most useless thing in the game

let it off ^^