It will not work. Sight would not show you the binoculars in 1st place or at tops would show the true nature of the binoculars - last book has exelent example of this when harry - well i leave the spoiler out.
From last book I presume that sight only shows you sources of energy -> living beings, souls, ghost, laylines, magic (life!) etc and would dim out (outlines mayby? or nothing at all) on mundane objects like rocks, cars, walls.
Mayby if magical object would be made to do this? but consider this, you take a peek of military base from afar and see 40 souls at 1 time? I say it screams for sensory overflow big time.
-V-