Trivex

[Boldt]

So I have to ask, every one seems to love it, my self included, why is it not used more? It's better than poly in every way and only 10% thicker at most, usually it's not even noticeable. Yet I see so many doctors and opticians shrink from it when it's brought up. Any ideas why?

[tx11]

Surfaced Trivex lenses cost more than poly...not to mention poly stock lenses. probably just because of price.

[WFruit]

The biggest drawback to it that I see is cost. It's usually a good deal more than Poly for the same product.

Perceived thickness is also an issue. Since it's 1.53 and Poly is 1.58, it's assumed that it will be thicker and thus heavier, despite the face that you need to be up near -10.00 before the thickness starts to become a factor, and it is the lightest weight material.

On another plus side, you can get it in Transitions in lens designs you can't get Poly in.

And the entire industry has had it pounded into their head that Poly is the greatest thing ever. Fortunately some of us have thick heads and it didn't pound all the way through.

[m0002a]

Essilor has been pushing polycarb for so long that many ECP's people are brainwashed, or have just been intimidated into submission by Essilor. It has only been relatively recently that Essilor made Trivex available for their lenses, so maybe things will eventually change. I personally was involved in a brouhaha on this board about 10 years ago with an Essilor rep about this subject, and I was almost thrown off the board (I got a lot of interesting private messages on the subject).

[Boldt]

And the entire industry has had it pounded into their head that Poly is the greatest thing ever. Fortunately some of us have thick heads and it didn't pound all the way through.

Love it!
I figured cost could be part, but I get asked "Will my edger cut it?" on a regular basis. On the bright side if I know the person in question I get to let my snarky side out a little with the "Lets find out." Followed by the "smoke" when it cuts. I usual get them a drink if I pull the joke.

[Hayde]

I would imagine it'd be hard to have time in the lab and not have a soft spot for Trivex. Still, some patients are very much out for the thinnest they can get on a budget. Plus poly gets a bum rap in some respects--(Uillean's profile has a blog link to a terrific DiSanto article on the powers necessary to manfiest abberation issues with poly. Got the chart printed for a cheat sheet at my dispense table. Thanks, U!)

Still, I've had all the stress marks and stress fractures I care to in this lifetime.

Many of us tend to oversimplify our pricing when it comes to upgrades---when we do it's easy for the trivex markup to exceed necessity on many lenses. In progressive lenses I find the difference pretty nominal and make sure to pass it through to the patient. In fact, when I think of all the work and hassle trivex saves me, I'm not averse to factoring that into Trivex' price.

[Boldt]

Damn it! Why did you shatter the ideas I had due to exaggerated information on the abbe values?!?!? ;^)
I agree about the stress marks and cracks, and in drill mounds...poly is the devil.
So it does make progressives a bit better then?

[m0002a]

Plus poly gets a bum rap in some respects--(Uillean's profile has a blog link to a terrific DiSanto article on the powers necessary to manfiest abberation issues with poly. Got the chart printed for a cheat sheet at my dispense table. Thanks, U!

Poly gets the rap it deserves. I just read the DiSanto article, and all that math is very nice and all, but I personally experienced horrendous chromatic aberration with polycarb in the reading area of a +4.50 -1.50@90 degrees, +2.00 add power progressive about 10 years ago. By horrendous, I mean very noticeable green and red fringing of text viewed with reading area of lens.Not to mention the distortion that was present in other areas, but not bad enough to color fringe. Problem was resolved by switching to 1.60.

[Boldt]

Playing devils advocate here, but with a higher + rx and a 1.5 cyl is when I understand that poly becomes evil. Trust me though with a Rx like that I would say 1.6 min 1.67 is what I would give a person first.

[ThatOneGuy]

In the pre digital age, trivex was almost an after thought when it came to availability, so nothing new was ever available in trivex (or so it seemed). In other words, it got frustrating to talk about trivex, then next thing you know, it isn't available with transitions or some other option. Also, Phoenix was terrible when it came to photochromics and yellowing.

[Boldt]

AH HA!
I can see that. Does Have you, or any one still had the yellowing? I have a 2 year old pair that's fine, but wonder if I'm an out side stat.

[Uilleann]

Historically, there have been several issues, none of which was particularly easy to overlook:
1. Cost - even to this day, it's still more $ on average when compared against an equivalent poly product.
2. Availability - while it's better today than say 5 years back, it still lags behind poly in lens design options across many labs offerings.
3. Thicker - while it is lighter in SG than poly, it's thicker profile tends to negate much weight savings.
4. Yellowing - this appears to be largely solved now, but until fairly recently, these lenses often yellowed even worse than HI materials.

It's slowly making inroads nationwide, but I would guess that overall it will be hard pressed to compete with poly. I think it will take a new material entirely to really jump start interest in something beyond poly or 1.60. A few have shown promise (at least on paper), but have yet to make any sort of industry wide roll out of course.

[becc971]

I shy away if we are edging it because trivex is mean to edgers. personally, I've never had an issue with poly and I've had very few patient's who have had issues with poly so I take no issue selling it. if they do, i'll put them in something else dammit!! :bounce: availability is also an issue.

[HarryChiling]

Not as easy to process on the lab side so powers are inconsistent on some Rxs which leads me to wonder if digital pals loose design details when processing.

On the finishing side causes extra wear and tear on equipment if you don't have the dedocated wheels for it.

On the plus side very nice clarity, tensile strength, and scratch resistant comparef to poly.

Poly and trivex both have a place in a dispensary, stock lenses tend to mitigate the negatives better for trivex.

Abbe tends to be less an issue in SV compared to MF, but a shorter corridor design with no prism thinning helps in poly.

[TEdFitz]

I haven't had to deal with the yellowing problem yet, but trivex is a big pain to polish and groove on rimless/semi-rimless mounts.