What is this "O 22" on my glasses?

I was cleaning a pair of polycarbonate glasses today and I noticed both
lenses says "O 22" near the center. It seemed to be pressing into the
plastic rather than printed. I hadn't cleaned them before with glasses on,
and with them I can't see the markings.

What the heck is it, and does it matter?

On Mar 13, 2:05 pm, "Toller" <Tol...@Yahoo.com> wrote:
> I was cleaning a pair of polycarbonate glasses today and I noticed both
> lenses says "O 22" near the center. It seemed to be pressing into the
> plastic rather than printed. I hadn't cleaned them before with glasses on,
> and with them I can't see the markings.
>
> What the heck is it, and does it matter?

its a marking that goes on progressive lenses that serve as reference
points.
it does not matter.

On Mar 13, 2:05 pm, "Toller" <Tol...@Yahoo.com> wrote:
> I was cleaning a pair of polycarbonate glasses today and I noticed both
> lenses says "O 22" near the center. It seemed to be pressing into the
> plastic rather than printed. I hadn't cleaned them before with glasses on,
> and with them I can't see the markings.
>
> What the heck is it, and does it matter?

the 22 means that the bifocal add is +2.25 diopters in strength. the
O is simply a position marker that allows opticians to line up and
correctly orient the lenses in the frame.