Trivex- what do you think?

[APV Optical]

Amen JOFELK !! :cheers:

[jofelk]

I would like to keep the accolades going for trivex.
Our vote, from the lab, to replace all poly in the future!!!!! Excelent to surface, edge, tint, drill, optics, no returns on drills FOR SPLITTING OR EDGE CRAZING.
GO AWAY POLY!!!!!
Bring on trivex in all lense styles!

[Jim Stone]

Heck Mr Pete ,
I don't believe you can get uncoated front surface Trivex. To blame the processers for the problems with poly cracks is to pass the buck. You sound like you work for Gentex or something.


As far as advantages, don't forget superior optical properties of Trivex. (And aint that what we are here for?)

And no, I don't work for Trivex. It works for me.

Pete Hanlin said:
[color=
I would venture that a Trivex lens that has an uncoated front surface is going to scratch relatively easily in real-life wear.
.

My point? When drilled and mounted properly, there are absolutely no issues with polycarbonate and drill mounts.

The only "advantage" that I would give Trivex in a drill mount is its resistance to damage by solvents.

[Jim G]

To add to Pete's post on drill mounts:

Dull drills will also cause cracking over time.
Drilling too fast creating too much heat is also a contributor.
Acetone and poly is a no-no.

Talked to someone recently who was using dental burrs to drill plastic lenses with great success. Anyone else heard of or tried this?

[Billy Brock]

Hello all,

In this reader's personal opinion and practical use only: I think you guys have finally hit upon my number one advantage for using PPG's Trivex based material ............ they do not split even when "improperly" mounted ! ! I no longer pay for the redo cost of a broken drill mount lens UNLESS the account allows me to process the Rx in Trivex.

Today's lab work can offer many choices and advantages to fit specific requirements. My personal preference is to go with the material that can even withstand improper mounting. The cost factor issue ? ......... just my personal opinion and practical use only: it is not the most important issue when compared to materials that split if improperly mounted(time lost to a redo & reputation are a couple of items than can't be purchased) ........... I come out a winner every time on Trivex Rx's.

THANK YOU PPG for the material ................ Hoya & Younger for the lenses ! ! ......... As of this posting, I have not encountered a single Trivex breakage warranty in my lab.

Enclosed image is one of my Trivex based jeweled designs.

[Pete Hanlin]

Would still disagree on the hardcoating. Consumers expectations are pretty much based upon uncoated CR-39; anything softer will only lead to increased dissatisfaction.
I agree... statements that Trivex does not require hardcoating are dubious at best. Heck, you don't HAVE to coat poly either (but if you don't the lens will be scratched the first time you clean it).

I would venture that a Trivex lens that has an uncoated front surface is going to scratch relatively easily in real-life wear. As far as back side coating goes, the back side is usually exposed to less wear and tear and careful consumers may get by without a SRC on the reverse side of the lens.

Regarding drill mounts, I have three that I wear pretty much constantly. I've had them yanked off my face by luggage dropping uncerimoniously from the overhead compartment. I've sat and/or stepped on each pair at least a couple times. I've had them fall through the engine bay of my car, and generally I have abused them by shoving them in luggage and every small space in my dashboard over and over again. I have yet to have one crack. Oh, and of course they are all polycarbonate.

My point? When drilled and mounted properly, there are absolutely no issues with polycarbonate and drill mounts. Put plainly, if you are experiencing cracked poly lenses in drill mounts, then the lenses were mounted improperly! The only "advantage" that I would give Trivex in a drill mount is its resistance to damage by solvents.

[paw]

Speaking as a consumer, I love my Trivex lenses! I have SV, A/R coated Trivex lenses in a rimless drilled frame, and they have been a pleasure to wear. My glasses have even gotten bumped TWICE and there are no stress cracks at all. I am really happy with Trivex as a wearer and as a dispenser.

[Robert Martellaro]

Susan Henault said:
Pete -- Good point about the specific gravity/light weight feature of Trivex. CR-39 is the only material over which one can say Trivex has a significant advantage (in terms of "as worn" weight).

Pete and Susan,

I use single vision Trilogy by Younger. This lens does have an aspheric front curve. With this in mind I think it would be fair to say that for Poly to have any thickness advantage (typically less than .5mm) it would have to be aspheric also. That would place Poly much closer in price to Trivex. In addition, aspheric Trivex would be lighter in weight than spherical Poly, especially in plus powers. 1.6 would mimic poly in thickness but would be noticably heavier than Trivex. The mass/index/density issue doesn't come into play in any significant way until the powers get above three diopters or so, which is probably less than half of the Rx population. Am I starting to sound like a spokesperson for PPG?:) Actually I wish they could have sacrificed some of the abbe for a higher index but I'am sure that was tried w/o success. Concerning the yellow tinge; I do see a trace of color when placed on a sheet of white paper compared to Poly.

Robert

[Jim Stone]

I think Scratch resitance coating are nessesary on some materials. 1.66 and above and of course poly. I will take a better look at trivex. If it is not required, I say leave it off. Like CR-39, if the customer is tought how and takes care, SR coatings are not much more than "snake oil".

[Jim G]

Wouldn't disagree on the drilling but I was remiss in not adding the 1.67 MR-10 material to the "approved" list for 3-piece mountings.

Would still disagree on the hardcoating. Consumers expectations are pretty much based upon uncoated CR-39; anything softer will only lead to increased dissatisfaction.

Hoya recommends 100% coating; Younger equivocates. I think that in either case, with a good tintable backside coating, you'll prefer tinting AFTER coating.

The new Younger tinting recommendations for untinted Trivex is to tint at about 170F for no more than 5 minutes at a time, allowing that to cool to room temp and cleaning thoroughly in soap and water before retinting. Repeat until desired depth of tint is attained. DO NOT use glycol based neutralizers (most); use only water w/ detergent.

[Jim Stone]

Younger recomends tinting before coating. The coating is not required, but some may prefer adding it. The trivex advantages are, better optics, lighter weight and less stress cracks than poly. I put better optics first for a reason. Optics are most important for me. The poly advantages are thinner and more lens styles. I'd go with trivex.

I remember, in the earley days of poly, a still prominate lab here in NC, put out a letter in total frustraition, about any poly lens that did turn out exceptible was "a lucky mistake". I think that this is still true to a degree. Shame is that although the process has improved some, out standards have been permanately somewhat eased. You ever have a poly pat' express dissapointment with accuity to find the lenses check fine? What did you do then? Shame!

[Jim G]

Poly and Trivex are the materials of choice for drill-mounts. Period.

I've always used uncoated (naked) CR-39 as the basis for determining if a lens requires a hard coat. Trivex has a Bayer of about 0.5 putting it about half-way between CR-39's 1.0 and poly's 0.1 (a good factory hardcoat will have a rating of 3 or above). That puts it into the definitely coat category. Plus, I believe that both Hoya and Younger would also recommend using a hard coat. Plus, the backside coating will make the tinting easier (uncoated Trivex is tough to tint).

I think the one disadvantage to Trivex is the lack of lens styles
currently available tho, as use and manufacturing costs are reduced, this should be overcome.

[APV Optical]

A lot of my accounts are starting to use the Trivex/Trilogy. Most of my jobs consist of drill mounts. I have to say I love it. The Optics after grinding to a 1.0 are phenomenal. Of course you dont want to grind a -.50 to a 1.0 and try edging, but higher minus powers from -2.00 and up produce a sweet finished product. The color has not been an issue. It does have a cosmetic/brown tone. Which only helps with glare especially after the AR is applied. Scratch resistance is equal to that of any mid index that goes uncoated. However we coat ours to produce a very scratch resistant, light weight, product with great optics. Edging is about like poly was before edgers were designed for poly. After you learn how to handle the material it is a breeze. It does require a learning curve when you first edge. I guess thats all I can think of at the time.

[Jim Stone]

Trivex is less likely to develope stress marks and cracks in rimless mountings. It will never be thinner than polydue to the index. It will always be lighter. It is not nessessary to apply scratch ressistant coating to the back surface of trivex (one of the culprits,I believe, giving poly a bad name by causing abberations) to trivex.

[Susan Henault]

Pete -- Good point about the specific gravity/light weight feature of Trivex. CR-39 is the only material over which one can say Trivex has a significant advantage (in terms of "as worn" weight).