Nathan said. <My eye doctor recommended two pairs of glasses. I have one
pair that is used for work, with the upper half optimised for 45 cm
(computer screen) and the lower half for 30 cm (reading). And the second
pair is for everything else, such as walking, cycling or driving. It is a
bit of a nuisance, but so be it.>
I use two pairs of bifocals to cope with my older eyes. One pair like
yours and one for other activities (ie reading optimised at #30cms and
one for greater distances). As I normally use a desktop, I keep the
appropriate pair by the monitor and change as I sit down.(frames are
slightly different so that I can tell at a glance).
In bright sunlight, I am careful to avoid the resting glasses acting as
ignition services, as I have seen the effect of a misplaced convex mirror
on a bedspread and a local house was badly damaged after fitting window
panes with fashionable bottle top(?) centres.
Themed Olympus Photo Exhibition: http://www.tope.nl/