Is it a VX-1, VX-2, VX-II, or Varix-II. Leupold has made lots of 3-9X scopes over the years in varying price ranges. Was the scope made in the 1970's, current production or somewhere in between.
I'd be suspicious of an older scope or one of less quality. But I'm guessing it may be your eyes. I'm 58 and never needed glasses. Occasionally use readers to see fine print, but distance vision has been fine and I've never had problems focusing a scope.
Until about 2 weeks ago. I was seeing double horizontal cross hairs on all of my scopes,( Leupold and Zeiss) and no amount of focusing helped. It was only my right eye, everything was clear when I mounted the rifle left handed, but I don't shoot that way. The problem was temporary and only lasted a couple of days, but I will be seeing the eye doc in a couple of weeks.