I'm trying to find my vision center but every test i do i always keep seeing double of the object. For instance, there's a method of folding a card in the shape of an L and taping that to your mirror and where ever it lines up straight on your face is supposed to be your vision center. Mine never lines up tho, i always see double, a ghost of the original. Which one am i supposed to go with? This is all so confusing! dadgumit!