On 28/08/2019 11:08, tim... wrote:


"dennis@home" wrote in message
...
On 27/08/2019 17:22, Bert Coules wrote:
They do look intriguing.Â* 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.Â* These might fit that bill.

IIRC they showed something similar on tomorrows world a long time ago.

my SLR camera from about 1980-something had an adjustable lens on the
viewfinder,

so the technology has been in commercial use for ages

tim




they all had but its not the same.
even more cameras have correction now.