In article . net,
tom koehler wrote:
http://zennioptical.com/cart/home.php

low prices here. Am not sure what the catch is.

They are made in China, cranked out at the factory level. No local
support/adjustment, no way to get lenses made for glasses you own
already, no way to get non-standard options, and DON'T make a typo when
entering your prescription. Your prescription probably does not have the
PD (or IPD) pupil distance, the correct spacing for the centers of the
lenses - you need to get that accurately measured to get a good result -
ask to have it put on your prescription, and realize that it may be
different for close-focus as your eyes rotate towards the center.

I've never ordered bifocals from them - but I did order my single-vision
"distance" and "readers" from them, and have been pleased with the
quality for the price. Given that I was coming from being disgusted with
dropping $180 on useless beer-goggle progressive lenses through a local
optician, I was not expecting much, but I was pleasantly surprised -
particularly that their hard-coated polycarbonate (stock standard, not
an add-on optional expense) has held up to the abuse I give glasses for
several years. I've used only glass or ceramic (photogray extra) for
years due to the way I'd kill plastic, and I haven't killed these yet.

--
Cats, coffee, chocolate...vices to live by