ID:271012
 
I want to know how to make the person see through objects without the object being deleted from sight, and so that only the person can see through.
Sounds like you want to use the trickster datum known as /image.

http://bwicki.byond.com/ByondBwicki.dmb?SecretImages

That should give you a basic idea of what to do (there's two demos link, just to give you an idea what to do)

- GhostAnime
Well, it could be that you want to make it so that the person can see through opaque objects. To do this, you can utilize either /image and write up your own system for displaying objects that would normally be out of your view, or you can modify mob.sight to suit your needs.
In response to GhostAnime
I have no idea how to use /image and I doubt I'll be able to learn how :\