Is there a physical difference between "one day" contacts and "two week" contacts?

I’m a contact lens wearer. I used to wear Acuvue 2 lenses, which they say to replace every two weeks. This last year, however, I’ve been wearing ‘1-day’ Acuvue lenses, which are a lot cheaper on a per-lens basis. Is there actually any difference between these differently marketed contact lenses? Both do a good job of fixing up my vision, and they look identical. (Thinner plastic on the one days, perhaps?)

If there is a difference, and the two weeks lenses are more durable, is that any reason NOT to wear the ‘1-days’ for longer than that? How long–two days, five days, two weeks? What’s the deal?

Harumph; I didn’t think this question was too boring. I’d bet a relatively high proportion of dopers wear contacts.

I’ll try to help you out fellow weekend doper.

I seem to recall one of the contact manufacturers being sued for just such a thing. The daily and weekly contacts were identical but they were charging more for the weekly ones on a per lens basis.

I’m not having much luck searching news sites though. What’s a good news site that goes back more than 30 days?

Oh… And I’m a Focus night and day guy myself.

I have used contacts for about 6 months. They were Specsavers 1-month lens, but by week 3 they were so thin that wearing them was uncomfortable and I couldn’t see very well. I ended up replacing them every two weeks.

I’ve never used single day lens, but I guess the material won’t last too long. Also my WAG is that the saline solution actually damages them, since they are not supposed to be disinfected.

Anyway, I think contacts are too much hassle. I believe a laser operation is the solution.

Well, here we go.

This is the best cite I could find.

Looks like it was Bausch and Lomb

Holy cow. From Folly’s link:

As a student of economics, this is the most incredible example of price discrimination I’ve ever seen…

I guess what you really want to know is whether the two types are currently the same.

My guess is that it’s still more expensive for them to make two different kinds than just one. But maybe they cripple the once-a-day ones to avoid class-action lawsuits.

Personally, I’m a fan of the once a month versions, but I guess they are kind of expensive. Still though, I can get quite a few years worth for the cost of laser surgery.

This was Johnson & Johnson, the Acuvue Daily lenses, which were identical, even to packaging, with the longer wear version. The only difference was in the prescription, and that alone determined the price. The FCC made them stop. This was years ago (10 years?) when the daily disposables first came out.

That’s FTC, of course.

If the FCC (the FDA?) made them “stop,” what do they do differently now? They still sell those two different lines of products; are they different lenses now?