And Now (Do You Really Want…)Trifocals

When It Comes To Spectacles; What are Trifocals?

I can’t remember where I first saw this… As you can work out, the current posts are a bit of a rag bag (or “miscellany” if you want to be polite) based on any old spectacles subjects.because I have a load of “drafts” that need to be published or deleted.

Anyhow I read about the so-called “concept of trifocals”,claiming that “Bifocals have ruled the scene for quite some time now”.

Spectacle Lens Itself

But trifocal lenses according to this long-forgotten source, deals with each of them separately, correcting vision presbyopias progressively. (And I think this is the key here,the word “progressively”.) So as far as I can make out these trifocals are not tri at all (other than they deal with three slightly separate problems- reading/intermediate range and long range) but vari-focals - surely?  And like vari-focals, they don’t have lines across the lens.

So really it’s like a progressive lens which makes a progressive change from distance vision to near vision with all the range in between.

So what an earth is this all about then?  To be onest I’m not sure…  The only oint would be if you needed to have a larger areaof one of the three sections rather than astraight progressive. Apparently this may be good forcomputer users.  Also apparently, they are becoming more rare in repsect of increasing use of progressives.

The image here is borrowed from Hollywood Optical, a lab who obviously still supply them to those who dispense them.