What is the max range for a Polycarb lens. I'm looking for a +11.00-1.00 lens. Can they go up to that high power?
What is the max range for a Polycarb lens. I'm looking for a +11.00-1.00 lens. Can they go up to that high power?
Depends - I've fit that high using a premium AR without any problems. But I've also fit +3.50 spheres and they can't deal with the color abberitions.
I've heard Hoya will be releasing their Trivex product in ultra high BCs, but I don't see anything on their site.
Another option is 1.67 or 1.70 - I've had both run that high without much issue. and there are aspheric options in 1.67 in that power range.
Last edited by Audiyoda; 07-17-2006 at 02:36 PM.
VE has semifinished blanks in 9.75 BC which should be OK for the desired power.
Make shure to keep the frame small and round!
yes-the range is actually higher but I'd recommend a 1.67 high index lens, like a seiko because it will be MUCH thinner...
but if you decide to go with a polycarb/featherwate lens-make sure it is aspheric.
a +9.75 BC is fine if its aspheric, but won't work if its not. You'll need a +12.00 BC-but I'd make sure that whatever BC that is used, that it matches your old pair along with lens material and frame shape/size.
Most importantly...what will you be using your glasses for and what do you want them to look like??
Last edited by lilchiken; 07-19-2006 at 11:14 PM.
ICE-TECH Advanced Lens Technologies can provide Individualized lenses with front curves up to base 11. All lenses are surfaced with digital freeform equipment and unequalled accuracy.
ICE-TECH lenses are currently available in both polycarbonate and 1.67 MR-10.
We also offer the Seiko Succeed backside individualized progressive.
There are us folks that think reguardless of availability, poly shouldn't be used over + or -5.00 max due to inherent distortions in the material.
Chip
My bet the patient is a child!
ChipALL POLYCARBONATE IS NOT THE SAMEThere are us folks that think reguardless of availability, poly shouldn't be used over + or -5.00 max due to inherent distortions in the material.
This maybe true for some polycarbonate material, however two basic factors control the quality of polycarbonate.
1-Type of injection used to manufacture the lens
2-The quality of the original polycarbonate material used to produce the lens.
Did the material become over heated during manufacturing?
Was it injected under excessive pressure?
Were the molds cleaned and maintained properly?
After the poly lens is produced then it must be prepared and hard coated.
Another source for quality issues.
There are some of us that don't think polycrap should be used for anything.Originally Posted by chip anderson
OK it's a medicaid patient who has extremely high aggression and only one eye...high index is nice but Medicaid won't pay for it..I don't like poly either but I wanted to see what the range is for poly..medicaid lab said it doesn't go up that high for poly so I just wanted to see what the actual available range was....
...and then there are those of us who personally use- and have dispensed 1,000s of pairs of polycarbonate quite successfully!
Essilor has a poly product that goes to -11.00, but nothing in our line is recommended up to a +11.00 (the aspheric lenses go up to a +8.00). Even Essilor's 1.74 is only recommended up to a +10.00.
Although poly gets slammed around a lot for "inherent aberrations" (whatever that's supposed to mean), the one factor that will come into play here is chromatic aberration. Even if the patient looks 5mm or so away from the OC, s/he will encounter 5.5 diopters of prism (and prism- along with abbe value- is the key factor in determining levels of chromatic aberration).
Interestingly enough, you can expect to create approximately the same amount of chromatic aberration with a 1.67 lens- but at least the lens will be somewhat thinner.
Of course, you could make the lenses from plastic to cut down on the chromatic distortion, but you're still going to have major issues with magnification. To be honest, if contact lenses are an option, they would probably provide better vision- with greater comfort- for this Rx.
PS- Does every thread have to be turned into a commercial? How does the casting/molding method used to create the lens have ANYTHING to do with someone looking for a +11.00 polycarbonate lens?!? Geesh! Yes, certain molding methods (which are used by Optima and others) result in less internal stress (which is not an aberration) within the lens. Even if internal stress had anything to do with quality of vision, it is only relevent for finished poly product (since the surfacing process removes the internal stress of the lens). I'm guessing a +11.00 polycarbonate lens is not going to be a finished product (even if a finished product were available, you'd want to surface such an Rx to avoid excessive thickness).
Pete Hanlin, ABOM
Vice President Professional Services
Essilor of America
http://linkedin.com/in/pete-hanlin-72a3a74
I like when people try and use birefringence as an example of poly's poor optics when heat tempered glasss exhibits birefringence as well:hammer:
How about aspheric 1.6 or spectralite? While not as cosmetically appealing as 1.67, it is a reasonable price product, that maybe the patient would be willing to pay the difference on?
You can upgrade a patient on Medicaid to better materials and charge them the difference. You just have to have a form stating that the patient realizes that the state doesn't cover this option, the extra cost and their signature. Collect the fee up front (or I have done half down, half when picked up) and submit for poly and show the upgrade to hi-index.
Cassandra
"Some believe in destiny, and some believe in fate. But I believe that happiness is something we create."-Something More by Sugarland
well, with only one eye and lots of aggression, you def need something that won't shatter!! so poly,1.67 and trivex would be a good idea- and good luck finding a lab that'll make a +11.00.
My lens book shows that Essilor has a +12.00 base semi-finished SV poly. I would call them and find out what the "true" base curve is. Even at +12.00 the ocular curve (back curve) will be very flat, inducing a fair amount of oblique astigmatism. If the true curve is less than about +10.75 the ocular curve becomes convex, possibly precluding the use of poly entirely, or at a minimum requiring special equipment and know-how to manufacture, not to mention gobs of oblique astigmatism and off-axis power error.
For the best vision consider the 5 drop (aspheric) from Bristol, or similar configurations from Essilor (Super Mod), Signet Armorlite (hyper aspheric) etc., and fit them like the old cataract lenses- vertical OCs per Martin's Rule, compensate for vertex, OCs within 2mm of geometric center, not to much of a disparity in the "A" and "B" measurements, and no sharp corners.
Hope this helps,
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
Pete:I said:Does every thread have to be turned into a commercial? How does the casting/molding method used to create the lens have ANYTHING to do with someone looking for a +11.00 polycarbonate lens?!? Geesh! Yes, certain molding methods (which are used by Optima and others) result in less internal stress (which is not an aberration) within the lens. Even if internal stress had anything to do with quality of vision, it is only relevent for finished poly product (since the surfacing process removes the internal stress of the lens). I'm guessing a +11.00 polycarbonate lens is not going to be a finished product (even if a finished product were available, you'd want to surface such an Rx to avoid excessive thickness).My point above was not anything to do with a commercial just the facts relating to different qualities of poly lenses available. Surfacing will relieve some stress from the lens but not most of the remaining stress, (for the amount of material used as the finished product). This stress is induced during semi-finished manufacturing thoughout the product.ALL POLYCARBONATE IS NOT THE SAME
This maybe true for some polycarbonate material, however two basic factors control the quality of polycarbonate.
1-Type of injection used to manufacture the lens
2-The quality of the original polycarbonate material used to produce the lens.
Did the material become over heated during manufacturing?
Was it injected under excessive pressure?
Were the molds cleaned and maintained properly?
After the poly lens is produced then it must be prepared and hard coated.
Another source for quality issues.
Basicly the faster the lenses are pushed through the process more stress is induced.
I can't imagine a +11.00 anything would shatter. I can certainly make a +11.00 poly lens but I'm not a medicaid lab, if that matters.
Bill Belanger
800-443-4639
At Laramy-K, we've run up to a +14.00 in poly. the Frame HAS to be small with minimal decentration. Saddle-back or bi convex curves can sometimes interfere with lash clearance so be careful but for some cases it beats the old aspheric lenticular!
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