I expect any of us who wear glasses have practiced shooting without them but - do you ever check those tiny screws on the frame?
I had a lens fall out yesterday, appropos nothing in particular... just fell out!! Fortunately, tho the screww had loosened right out, it was not lost and it took moments to do it all up - with thread lock!
If however (per Murphy) such a thing occurred at a most inconvenient time - IMO it sure ain't gonna help! Therefore I reckon a routine inspection of glasses is a worthwhile move.