Duty to Warn, again...

[DoubleD]

Hi, haven't participated for a while, but felt I needed to add my experiences to some other conversation on Poly, Trivex, and Duty To Warn.
I over the past 35 years have direct experience in the development of today's DUTY TO WARN (issues), and support this even more today.
In past 3 months, I personally have had 6 patients return to me just to say thanks for giving me Poly/Trivex. Their expereince: no serious medical damages- all had serious impacts
deer through windshield
18 inch fishing lure
piece of wood from table saw
projectile from lawn mower
and 2 fallen on face (quite elderly)
While I support polycarbonate as pricing same as CR39 (no-that is legal, I can charge what I want), I do love the Trivex, and fit much in both materials.
In past I have been drawn to court in issues of lost sight due to plastic and glass lenses. That is NOT fun, nor did we help that patient originally.
Duty to warn is just that. WE are professionals, and is is our responsibility to advise on best medical appliances.
My 2 cents.
Denny

[wabmorgan]

I know of a case where a girl was shot through a cr-39 lens with a bb gun. While no serious eye injury occurred.... she would have been better off in poly where this probably wouldn't have been an issue.

[Optician Magician]

I had an ederly man come in today that was VERY thankful he had poly lenses. He fell and landed right on his face, his frame broke at the endpiece/temple area and actually embeded in his cheek, but his lenses stayed intact and protected his eyes. I hate to think of what damage he would have had if he were wearing cr-39.

[Aussie]

My first choice is Trivex then Polycarbonate,mainly because solvents(metho,acetone etc.)will damage polycarb but not trivex

[CuriousCat]

My experience with poly is personal. I love to sew and would rather be at my sewing machine than just about anywhere else. One of the cardinal rules in sewing is NEVER sew over pins. I did it anyway several years ago and the needle, not the pin, broke and bounced off my glasses. Would CR have provided the same barrier? Probably. Was I thankful that I only wear Poly? You bet!

[Aussie]

My experience with poly is personal. I love to sew and would rather be at my sewing machine than just about anywhere else. One of the cardinal rules in sewing is NEVER sew over pins. I did it anyway several years ago and the needle, not the pin, broke and bounced off my glasses. Would CR have provided the same barrier? Probably. Was I thankful that I only wear Poly? You bet!

I'm sure trivex would offer the same protection without the disadvantages of polycarbonate(lesser optical quality lower abbe value,lesser tensile strength & reaction to solvents)

[OpticLabRat]

I was drilling out a screw recently with a dull drill bit, ("I know I know")
and sure enough....The drill bit snapped and shot straight at my eye leaving a deep dent in my poly lens. This would have surely pierced my eye.
I used this as an example to the rest of my coworkers to ALWAYS wear safety glasses while using tools no matter how small of a task you are doing.....And to never use a dull drill bit.:o

[chip anderson]

Once in my youth (yes, I had a youth) I was cutting a hole in cabinet top to install a sink. I was having trouble following my outline due to sawdust. Being the brilliant fool that I am, I found that I could hold the sabre saw under the table and see my lines from above. Result, the blade snapped off and hit me right in the center of the right lens.
Sorry to disappoint, I didn't have eye damage and my lenses were dress hardened glass (Which scratched but didn't break).

Chip

[Barry Santini]

that prescribers would do well to advise *all* of their patients, whether they *need* an Rx or not, to wear protective eyewear (or perhaps even a crash helmet) in order to get through the travails that life may throw at them.

And I know of no more suitable country to get this done, with a "skilled workforce" in abundance with which to litigate these matters, than the good ol' US of A.

My (more than) two cents..

Barry

[Happylady]

Remember Trivex is not nearly as impact resistant when you put an AR on it. Poly stays impact resistant with an AR. I like Trivex but since I sell AR on 90% of my jobs it is important to know this.

[RT]

Remember Trivex is not nearly as impact resistant when you put an AR on it. Poly stays impact resistant with an AR.

That's probably far too general a statement without showing some data. There are many variations in AR coating processes, some of which have a much greater effect on impact resistance than others. That's why it is up to the AR coater to demonstrate the impact resistance of their process.

[CuriousCat]

I'm sure trivex would offer the same protection without the disadvantages of polycarbonate(lesser optical quality lower abbe value,lesser tensile strength & reaction to solvents)

Perhaps, but I happen to like poly as a material and have been using it since the mid 70's with no problem at all.

[hcjilson]

I would preface what I say by saying I am a firm believer in Trivex. It is my material of choice HOWEVER.....I wear both poly and trivex.....and I PROMISE you, the human eye can not detect the visual difference between the two products from the average wearer's point of view. You may rant about index of refraction and chromatic aberation all you want but the difference is infinitessimal, and the customer doesn't see it 99.999 % of the time.

[Aussie]

Perhaps, but I happen to like poly as a material and have been using it since the mid 70's with no problem at all.

Fair Enough.

[Aussie]

[quote=hcjilson;213698You may rant about index of refraction and chromatic aberation all you want but the difference is infinitessimal, and the customer doesn't see it 99.999 % of the time.[/quote]

Who is Ranting? It is common knowledge.Polycarbonate(abbe value 29) has more chromatic aberration than Trivex(abbe value 45).It is more obvious in higher power Rx.
The Fact is that Trivex is Optically Superior.
This may not be obvious in your own particular Rx.

[MarcE]

but the difference is infinitessimal, and the customer doesn't see it 99.999 % of the time.

I would say the customer doesn't see it about 97% of the time. And the 3% are +4.00 and higher hyperopes with high cyl that have been wearing CR-39. If you havent' heard it before, save yourself some trouble. Don't put them in poly. They will like the the thin lens until they put it on. Then the flat curve (they like magnification), chromatic aberations, and off center clarity will bug them.

Trivex is a decent choice for them. The optical clarity and steeper BC will approximate what they are used to.

[hcjilson]

Who is Ranting? It is common knowledge.Polycarbonate(abbe value 29) has more chromatic aberration than Trivex(abbe value 45).It is more obvious in higher power Rx.
The Fact is that Trivex is Optically Superior.
This may not be obvious in your own particular Rx.

G'Day Mate! Welcome to Optiboard -my rx follows:
od +5.25-.50X68
os +4.75-.50X110 +3.00 add ou.

If it were that obvious I think I would notice it, after all, I've had 48 years to learn what to look for. I'll stand my my 99.999% figure.....while still recomending Trivex.

[CuriousCat]

I'm with Harry, though I'm a low + with a 2.50 add. I just never drank the anti-poly kool-aid.

[Aussie]

G'Day Mate! Welcome to Optiboard -my rx follows:
od +5.25-.50X68
os +4.75-.50X110 +3.00 add ou.

If it were that obvious I think I would notice it, after all, I've had 48 years to learn what to look for. I'll stand my my 99.999% figure.....while still recomending Trivex.

G'Day,
Thanks for the warm welcome,
If you really believe the 99.999%? figure,why not stick with polycarb for all.

[Aussie]

I just never drank the anti-poly kool-aid.

It's not a matter of being anti-poly,just a matter of opening your eyes and accepting that there are better lenses out there with the advantages of polycarbonate and less of the disadvantages of polycarbonate.Giving your customers the best available lens material

[hcjilson]

G'Day,
Thanks for the warm welcome,
If you really believe the 99.999%? figure,why not stick with polycarb for all.

Trivex is lighter and safer.

[HarryChiling]

Remember Trivex is not nearly as impact resistant when you put an AR on it. Poly stays impact resistant with an AR. I like Trivex but since I sell AR on 90% of my jobs it is important to know this.

AR coating on any material reduces the fracture resistant properties of the lens, so does the base curve. If you are fitting a person in a 1.0mm ct aspheric poly with AR don't fool yourself into thinking you are giving that person a safer lens.

Source #1
http://cat.inist.fr/?aModele=afficheN&cpsidt=2975424
Source #2
http://www.optvissci.com/pt/re/ovs/f...7000-00015.htm

[Bonilla-warford]

All,

I've been engaged in a thread elsewhere with those that do not beleive in Duty to Warn and routinely provide CR-30 lenses to young kids.

I've been trying to track down this reference in Eyecare Business:

"Somewhat later, in 1993, a sizeable judgment was awarded over the failure of an optical store to properly inform a patient about the impact resistance of various lens materials. The judgment was widely publicized in trade magazines, and informing patients about eyewear safety issues became a hot issue for professional offices and retail optical stores."

Can anyone point me in this direction?

Thanks

Nate

[wabmorgan]

Poly or Trivex processed at even 1.0 still has a greater impact resistance than 2.0 cr-39.

Poly and trivex are the safest. Hence why they are sold under duty to warn as the lens of choice.

Poly and Trivex are substantially more impact than cr-39, even when the cr-39 lens is thicker

IMPACT RESISTANCE
Are Trilogy lenses as impact resistant as polycarbonate?
Trilogy and polycarbonate have comparable impact performance.
It is challenging to define absolute impact performance when two plastics are as different as polycarbonate and Trilogy, and when both have such high intrinsic strength. In some tests, Trilogy is obviously stronger than polycarbonate. In other tests, polycarbonate does better than Trilogy. However, regardless of the test technique, both materials far exceed the impact performance of other lens materials. Please review the attached graph that represents the magnitude of this safety margin, even when Trilogy and polycarbonate lenses are surfaced to only 1mm center thickness.

What test is used to measure impact resistance?
One of the ways Younger qualifies impact resistance on each batch of Trilogy lenses is by using an extremely severe impact test. In this test a 1.1 lb sharpened steel missile is dropped onto the part from a height of 50 inches. This test will actually pierce a hole through polycarbonate while still leaving Trilogy lenses intact at the same thickness.

[Uncle Fester]

It's been kinda boring around here lately so I'll stir the pot by asking

In past I have been drawn to court in issues of lost sight due to plastic and glass lenses. That is NOT fun, nor did we help that patient originally.

Were you compensated for your time in testifying?

Who solicited your expertise and how did they find out about you?

Do you sell contacts?

Now give me a minute to put on my helmet and flak jacket:)
Chip- Cover my back:):)