All I asked was if there were any states that required poly by law, everyone else started into the different material stuff.Originally Posted by Paul Smith LDO
All I asked was if there were any states that required poly by law, everyone else started into the different material stuff.
"what i need is a strong drink and a peer group." ... Douglas Adams - Hitchikers Guide to the Galaxy
Never let a simple post go to waste !
Yes, this is what we do. I'm surprised that you didn't get Grandma's Thanksgiving stuffing recipe but hope springs eternal.
I didn't attend the funeral, but I sent a nice letter saying I approved of it. Mark Twain
that would probably have been more useful
"what i need is a strong drink and a peer group." ... Douglas Adams - Hitchikers Guide to the Galaxy
No one really wants to know what the secret ingredient in her recipe actually is... ...
What about the dangerous BPAs?
Still would love to see a chart showing the average impact resistance of FDA approved CR-39 ophthalmic lenses, and the same for poly. Does COLTS have that info perhaps?
I would love to see a chart of all the common plastics, resins, and glasses used to make lenses listed in order with values, from weakest to strongest, with respect to impact resistance.
From what I can tell, this was done, in at least some capacity, according to PubMed, for a JAMA article, all the way back in 1997.
Poly shavings
"what i need is a strong drink and a peer group." ... Douglas Adams - Hitchikers Guide to the Galaxy
In the early 1970s, during a routine visit by optical industry leaders to the FDA...
When it comes to eye protection, the United States is unique. This is the only country that mandates minimum impact protection for spectacle lenses. When all ophthalmic lenses were made of glass, there were numerous attempts to convince Congress to pass legislation requiring tempered lenses for consumer protection.
In the early 1970s, during a routine visit by optical industry leaders to the Food and Drug Administration (FDA), the FDA told the group that it could take years to get eyeglass safety legislated. Instead, they advised solving the problem with a simple FDA ruling.
As it turned out, such a ruling was issued very soon thereafter--in 1972--and from then until now, the U.S. has required that all ophthalmic lenses meet minimum impact resistance standards.
That ruling produced one unexpected result that would come to impact eyewear in the U.S. in a very significant way. It accelerated America's conversion from glass lenses to plastic. Even today, more than 30 years later, the U.S. is the only country that turned so completely away from glass. Though still popular in some categories, glass currently represents less than five percent of lens sales in the U.S.
See all of it: ===========>
http://www.eyecarebusiness.com/artic...rticleID=50448
There is a world of difference between legislation and rulings. The legislative process is a long drawn out affair which gives everyone a chance to put their two cents worth into the topic under discussion. It's then got to be voted on by committees and finally both Houses of the appropriate State or Federal Legislatures. It is then subject to veto. Small wonder it takes so long to get anything done.
Rulings, on the other hand merely require some pencil necked geek in some obscure orifice in some darkened room to post the as a mandate. No discussion, no debate, no nothing.
So it is clear. It is easier to get a single regulator in the satchel than a whole congress. It’s a big club and we ain’t in it.
Great question. Not specifically sure how they quantify it.
This Vision Council doc only references the pass/fail drop ball.
This old abstract hints at what the hard numbers look like.
Anyone else have some better citations?
Interesting. Specifically, I'm interested to learn how, in litigious terms, that any dispenser can be sued for injury if there are no data easily available showing how "dangerous" CR-39 is compared to poly lenses when being worn by a child in a given environment. Courts of law love this stuff - it's highly strange this information just isn't available it seems.
Further, the abstract linked above specifically deals with projectiles fired directly at lenses with the specific intent to "penetrate" the material. No mention of shattering properties, or any mention that I saw on first glance of real world scenarios. In addition, regardless of the fact that their test didn't "penetrate" the poly lens with a .22 cal bullet...I can guarantee that any child, wearing poly lenses in any child's frame who is then shot in the face/eye with a .22, will absolutely have injury issues to deal with - regardless of the lens material. That amount of force is simply not able to be absorbed without consequence.
Like an LEO suing a bullet proof vest company because they were shot resulting in broken ribs, perhaps a collapsed lung, and massive bruising...even though the vest technically stopped the bullet from "penetrating"...it just doesn't seem like good data for real world wearing scenarios. *shrug*
Last edited by Uilleann; 10-07-2016 at 10:23 AM.
As far as litigation goes anyone can sue anyone for anything.
Read the newspapers and you will see plenty of examples of this. Spill hot coffee on your self, sue McDonalds and walk away with a million bucks of money.
There is always a savage trial attorney and a sympathetic jury that will see things your way. However, these litigations do occasionally get clouded over by facts but not often.
Just googled it and found only 5% of personal injury lawsuits go to trial. It's all about having enough insurance to make it go away. That said- I'd argue long and hard that a monocular patient be in poly or trivex.
That's just a matter of common sense. We should not need laws and regulations enforced by courts and insurance payoffs to prevent us from stupid behavior.
Not an impact test but a tensile strength test of our most common materials:
Sound practice to be sure UF. Though one would think that there would be actual legislation requiring use of safety rated materials/designs of ophthalmic lenses in most/all states. Per the OP's initial querry: "Are there states that require Poly for kids under 18 BY LAW? by law is they key." But it seems that this is not the case.
But then again, why not simply offer CR-39 or glass, surfaced to safety thickness, reducing cost to the patient, and potentially improving the quality of optics? Or has fashion once again trumped clarity and cost?
I'm still unclear, since ALL ophthalmic lenses dispensed in the US are required to maintain minimum impact requirements, why precisely CR-39 (I would ad full UV protection personally) isn't considered a viable option for children's lenses. It is lawfully required to exhibit impact resistance to a government standard -seemingly much more stringent than anywhere else on earth - likely exceeding the ability of the lens to shatter while still held in an ophthalmic frame. But get hit with enough force to actually cause the lens to shatter, and I'll gather your face has other more pressing issues to worry about.
We give kids poly with no up charge. The price isn't that substantially different is SV.
Makes sense to me.
Look up the Izod Impact Strength, this is a common value that can be found for many materials. You may have to look through engineering material data sheets and be able to decipher the actual monomer / polymer name to find these values.
The only problem with that is that the IIS is not representative of the test the FDA uses to determine impact resistance.
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