Bert Coules wrote

They do look intriguing. I use and like varifocals but there are times
(and in differing circumstances) where they're not ideal and a single
prescription pair would be better. These might fit that bill.

Yeah, just ordered some.

I normally wear what works best for the computer screen and
now find it hard to read the shelf labels in the supermarket etc.
Be handy to be able to change the prescription on the fly for that.