PD can sometimes be given as a "mono" fraction, such as 32/34; that's the distance from the center of the pupil to the center of the bridge of the nose, the first number corresponding to the right eye, the second to the left. Ordinarily it's written like R32 L34. For progressives or bifocals (some of us can't wear progressives) the larger number (which I assume would be written first, such as 66/63) would be for "distance," the other for "reading," or, in my case, "computer," since, for reading, I hold a book closer to my eyes than I would view a computer screen.
If I sit at a computer screen I grab my "computer glasses," for reading I grab my "reading glasses," if I drive my car I grab my "driving glasses," since, thanks to Ira and GlassyEyes, I can now afford to have several of each kind. I actually do have some bifocals that I ordinarily wear socially, or when I can't carry a specialized pair, but it's such a joy to be able to put on my reading glasses so I can read the price label on the bottom shelf at the grocery without straining my neck looking through that little "reading" window at the bottom of the bifocal lens. What I really need is glasses that would adjust by twisting a little knob on the side to change the refractive value of the lens... WHL Character is doing the right thing when no one is watching. On Jun 15, 2:12 pm, powrwrap <[email protected]> wrote: > On Jun 13, 11:53 am, Sasha <[email protected]> wrote: > > > Re. PD: I learned this week that PD is often given as a fraction, such > > as 58/61. > > The second, higher number is the one to use for progressives, the > > lower for reading glasses. > > Or so I'm told. > > > Anyone know otherwise? > > Almost got it. The number is not a fraction, it's actually two > numbers. Only progressives have 2 PD numbers. The higher number is for > distance vision, the lower number is for reading. -- Check us out at the oft-updated http://glassyeyes.blogspot.com! You received this message because you are subscribed to the Google Groups "GlassyEyes" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/glassyeyes?hl=en
