0 glasses with lenses that are divided into two parts. The upper half is for looking at things far away and the lower half is for reading or for looking at things that are near.
1 glasses with an upper part for looking at things far away and a lower part for reading or looking at things that are near
But under normal circumstances the wearer of bifocals takes no notice of the discontinuity.
The question then is, does the world appear discontinuous to viewers of bifocals?
If it is a logical argument that one ought to pay double for bifocals, what would be the charge for a monocle?
If it is argued that bifocals are the equivalent of two pairs of glasses, the answer is that they can be manufactured more cheaply.
She needs bifocals which cannot be supplied quickly.
So far as special types are concerned, bifocals and others, delivery dates are steadily improving month by month.
It costs £57 for a pair of old-fashioned private sector bifocals.
The consultants enclosed a typical prescription for a pair of bifocals.