put a waterproof chord on an old pair of prescription glasses
the idea of putting holes in the arms is a good one
i use a hangman's knot to attach to the arms, but may try the hole thing where possible
i place a knot in chord where it will be at the back of my head
this leaves a loop
to this loop i attach a fisherman's bopper - that floaty thing
if large enough bopper, the glasses float when they come off - and they will
at the very least descent will be slowed down
this has worked fine for me for many years
sun never bothered me and so no polarized or other darkening features
i can sail and find my car without my glasses , but why bother - enjoy the scenery when sailing too much
hope everyone finds something that works for them !! and shares it here