Never flown helicopters but my jet transport experience went:
Near vision deteriorating LHS on two crew a/c (B757/767) - used reading glasses perched on nose for instruments and charts. Meant sliding specs up nose to view o/h panel. Also good for schoolmaster glances over top to amuse FOs
Long vision not pin sharp but OK for landing perspective.
Went LHS on 3 crew (B747) and realised I couldn't monitor FE as required by SOP because I couldn't focus on his panel. Clearly going to be caught out by checker or, far worse, real emergency so moved to varifocals. I prefer large lenses because the required strength areas are larger. (Mrs Bas said they didn't look becoming so I asked her which design would make me most attractive to young ladies. She laughed in a derisory fashion but no further complaints.)
Using these did mean cranking my neck back to focus on the o/h panel. If that had been a requirement whilst flying on instruments, the risk of disorientation would have required me to consider trifocals but it wasn't.
I did have a pair of varifocals made with a graduated tint from clear at the bottom to fairly light sunglasses at top. They were expensive but good to use in glare.
Welcome to the club!
