If you are normally the sole use of your binoculars you probably don't adjust the barrels much. ( the distance between your eyes).
However occasionally we all lend our bins to someone else who adjusts them for their eyes.
What I do is set up my bins exactly as I like them then make a small mark with a sharp blade across the hinge in the middle so I can re- align the barrels instantly.
I do the same using Tipex correction fluid,just a couple of spots to line up on.It is surprisingly weatherproof.
In my case I buy the stealer of bins her own set for Christmas.
Edit ; which arrived in the post this morning, very nice they are too. Thank you RSPB :)
I must have close set eyes because I have the barrels squeezed as close together as they will go, so I don't need to make a mark. This is one reason I struggled to find a pair I am comfortable using until finding my present ones.