Max Demian explained :
Tell us how you get on. Could be fiddly to adjust "on the fly".

Might be handy for someone like me, who wears different diopters for
differing purposes - one for close, one for TV, another for driving,
but swapping focus would be very fiddely. I would want a push button
select, but not practical. Even better, remote control, or automatic so
they adjust themselves.

Think I will stick with my throwaway £1 glasses :-)