question for the optical guru's out there

I prefer using binoculars without my glasses. Every pair I have though, I have to unscrew the right primary tube a couple turns in order that the dual images I see otherwise will merge into one. What property of my vision deficiency causes this and are there binoculars that are built to compensate for it? I don't like having to tweak the optics, one cause then they are screwed up for anyone else and two cause it leaves a path for dirt to get in.

Thanks in advance.

Randy