What material do you put a child under 10 in with a RX of +/-8 or higher?
What material do you put a chlid above 10 in with a RX of +/- 8 or higher?
Are there SC state laws for children and materials?
What about cosmetics if you put in poly?
Do you talk to the parents and let them decide?
Ginny
1) Trivex, if I can get it in that patient's Rx.
2) Trivex, if I can get it in that patient's Rx.
3) I don't know; maybe your state's licensing board of optician's association can give you a lead on how to find out.
4) I don't use poly because of the visual problems, not cosmetics.
5) I talk with the parents and tell them frankly that, in Rxs that high, visual clarity in poly is seriously compromised, and that, for children of any age 18 or under, the standard of care is to use the safest lens materials available to us. And all of that, added together, means Trivex if it's available.
I hope this helps!
Andrew
"One must remember that at the end of the road, there is a path" --- Fortune Cookie
Rigid or soft contact lenses, These people only need glasses to find the bathroom and their contact lenses with.
Chip
aspheric poly. or super modular aspheric(cr-39),if available. And of course Trivex...aspheric.
Trivex Trivex Trivex !!!!!!!!!
I find it interesting how many people still are clinging to the trivex/trilogy/phoenix bandwagon. Poly did indeed have a lower adaption ration when compared against CR-39 and glass years ago, though most poly lenses available work just fine today. Poly is still thinner, lighter, and is the most impact resistant lens material available. Period. The issues with chromatic aberration, and it's lower Abbe value should always be considered. However, as an industry, we need to be careful not to loose sight of the forrest for the trees. Polycarbonate is used in many MANY applications that include optical and safety scenarios, with absolutely no ill effects reported from users pertaining to chromatic aberration or highly substandard optics.
Trivex as a material was a novel concept, and good for those behind it thinking out of the box a bit. Just remember that because some things aren't the 'latest, greatest' or have a large marketing budget, it does not make them obsolete.
I would also agree that a serious discussion with the patient and their parents about contact lenses, or other corneal therapies may be a perfectly viable place to start. Then with lifestyle questions, and a wide range of options, decide together with the ECP, patient and parent(s) what the best course will be moving forward.
All the best in your dispensing.
Brian~
Originally Posted by Uilleann
I'll jump in here. We use poly for kids +-2, or 3 if we get a perfect fit.
Then we go Trivex, until around 6, then 1.60 or 1.70. No 1.67, no 1.74.
Believe me when I say you underestimate the effects of low ABBE. If you're comfortable with a patient having their vision looking like a 3-D picture without the 3-D glasses when you get very far off center(As I do), then go ahead and use poly. And don't forget to remove that period after the most impact resistant after poly. Granted poly is thinner and as safe as Trivex, but poly is not the single most impact resistant material.
I speak from personal experience with low ABBE thick lenses. Though not for much longer.
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
Made a pair the other day for a kid. Plano in the right. -13.50 -250 in the left. Used 1.67. Kid still can't hold his head straight.
Edkin:
Now your patient surely needed a contact, the very idea of a 13-15 diopter imballance with forward lenses is abhorrent. Have we forgotten all the basics we once knew?
Image is so much smaller on the corrected eye that I don't even want to think about it. The distortion and the chromatic aberation on the corrected anywhere out side of about 15 degrees from center will result in the patient not using the eye at all (assumes the plano eye is functional and if not it should have some sort of ballance lens.)
Even with a contact of correct power and cylinder the image size would be a problem albeit a much smaller one. Don't they study optics at all in residency anymore?
Chip
Interesting to hear. I'd be interested to meet some of the patients you have had difficulty with. We simply do not. Not the way the industry seems to lean towards what seem to be almost scare tactics against poly. It is perfectly viable, and well suited in many cases. What readily available lens material do you believe to be more impact resistant than polycarbonate?
Thanks.
Even our state's medicaid will deem someone as medically necessary for contacts when there is that amount of ansio.
Heck, at -8.00 or so, if we can attest to at least one full line more of acuity in contacts compared to glasses, then they will cover it as well. Hard or soft lenses.
"Some believe in destiny, and some believe in fate. But I believe that happiness is something we create."-Something More by Sugarland
I won't answer for Dragon, he is very capable of that himself.
I say Trivex. It is a wonderful material. Have you heard of it?
Andrew,
Have you ever thought of using Trivex?
;):cheers::cheers::cheers::D
That's about what I'm dealing with now. Gotta have one eye patched at all times. Oddly, it's way better with no glasses because the -14.25 eye is so blurry, you don't notice it.
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
If it were up tome I would patch both eyes and let him cross a busy intersection.
This kid is the devil!
Well, for starter, me. I'm a minus 14.25 -2.25. I have tried poly and 1.67 and the optic experience is miserable, intolerable and just plain unwearable, unless I never move my eyes from OC. 1.70 is better and so far the best combination of thinness and tolerable chromatic distortion for high myopes. Lesser myopes will be bothered less and some people's tolerance of this is quite high. I have had cataract surgery on one of my eyes and it's now a -1.50 -1.50. And when looking through my very thin Trivex lens in that eye, I can not find any of the chromatic abberation that is so evident, even in the 1.70, which is the best of the thinnest lenses in that respect.
As far as patients go, we had a kid, about 6, in awhile back and he was kind of sheepish, and his mother said to him "Go on, tell him what the problem is with your new glasses." So the kid said, "At school, I have a black friend. And when I look at him like this, " he said, turning his eyes to the edge of his frames "he turns purple." The mother was acting like it was the dang foolest thing she ever heard when I told her I knew what the problem was. He was about a -4.50-2.00 and we'd put him in poly. So I switched him to Trivex and his problem went away.
Poly used to be the only go-to high strength material.And it filled that role as well as it couold, thanks to improvements to it's clarity over the years. (No more embedded carbon micro-grains - YAY!) But it's always had it's main glaring ABBE weakness that limits it's range. Trivex fills that range also and is even better in drilmounts than poly. Since we've switched to mandatory Trivex in all drillmounts we sre still at zero cracking around drill holes and even better, zero breakages, even when driven over by a truck.
So I still use a fair amount of sv poly, it's limited in power range and banned in drillmounts.
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
No, just grind 5 prism base out in one eye and 5 base in on the other and watch him walk into walls.:D
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
No; really?? :D:cheers::D
Andrew
"One must remember that at the end of the road, there is a path" --- Fortune Cookie
Just to expand on my previous post:
I will use poly on kids with Rxs up to about a +2.50 and a -4.00. There seem to be far fewer problems with ABBE-related issues in lower powers. Once the powers get above that, I'll go to Trivex. And, of course, if a patient exhibits ABBE-related problems (what Uncle Fester dubbed "polycarbitis"), I'll switch them out of it.
Dragon, thank you, as always, for reminding me of the value of 1.70. My question is, how's its impact-resistance?
Thanks much.
Andrew
"One must remember that at the end of the road, there is a path" --- Fortune Cookie
Interesting indeed. Your experience is vastly different it seems from mine and those I've worked with here. Fair play. We're very happy with the optics and the lighter weight, better impact resistance and thinner centers available in poly. Trixex/Trilogy/Phoenix historically has cracked, yellowed, chipped, and had greater coating adhesion issues overall than any other material I've used. Now it wasn't with every pair, but it was more than we were ever willing to deal with. Before anyone thinks we didn't do our homework, we did. The lenses were not all ordered from the same supplier, lab, coating centers etc. And the problems with this particular material were readily apparent.
Glad it works for you. Polycarbonate works perfectly well for us.
All the best.
Each to their own. I'm sorry you're convinced poly is lighter and stronger than Trivex, because objective data proves otherwise.Check their respective densities.
You would also feel otherwise if your Rx was very strong and someone forced you into a poor choice of lens material because it's not their favorite material. I'm not trying to change your mind, just suggesting something other than poly for real high Rxs. After all,we're here to improve everyone's performance and knowledge. Just for kicks, next time you have a high minus Rx, ask the customer which they would rather have - a really thin lens with compromised optics and blurry off-axis vision, or a slightly thicker lens with clearer vision.
But, poly does have many uses in low powers, though not as many as the old Polycarbonate Lens Council said, while they tried to get about every other lens material outlawed.
So, I'll continue to replace all the cracked poly, the yellowed and highly scratched poly I see every day, while in the last year, we've only had one coating adhesion failure on trouble-free Trivex and have had them survive being run over with trucks.
:cheers::cheers:
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
Andrew, I don't have impact resistance data on the 1.70 index. It does have a pretty high tensile strength, according to Hoya
http://www.hoya.ca/index.php?SID=48b...3&page_id=4419
I have to assume it's pretty high - wait a minute! I just changed my right lens for the last time, let me go drop-ball it. OK, it survived the safety drop ball at a CT of 1.3 undamaged with AR, even. So I guess it's a fairly high impact-resistance level.
And I see Polycore now has theirs out with a 1.71 index.
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
Excellent! Thank you so much, and extra points for actually drop-ball-testing it. :cheers::cheers:
Andrew
"One must remember that at the end of the road, there is a path" --- Fortune Cookie
The correct answer would be none, trivex is a great lens material but is not as impact resistant as poly, although you do have to factor that at a +8.00 even CR-39 is going to be made to athickness that would withstand impact except maybe at the edges.
I think that says it all for me, and Fezz was the one whom turned me onto trivex, could it be better, sure, could it be worse, of course but it's a great material and any optician without it in the tool belt especially now that the cost difference is negligable would be foolish, IMO.
Trivex is a brand name on patent, correct? How long will it be before it goes off patent and is available as own brand from other manufacturers?
Our only choice is high index. I'd rather do Trivex, but it's not available to us.
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