Just curious if any opticians or lab folks have an opinion on putting polarized lenses in semi rimless frames? NVM just saw an old thread. I'll read that first.
Just curious if any opticians or lab folks have an opinion on putting polarized lenses in semi rimless frames? NVM just saw an old thread. I'll read that first.
Last edited by Bcmarve1970; 06-10-2018 at 09:08 AM.
Ok I read an old post on using polarized lenses in semi rimless frames. The reason I am asking is that yesterday I sold a pair of sunglasses to a guy. He wanted sunlenses in a semi rimless frame. I know that in the past I have declined putting lenses in these frame. However over the years I have heard conflicting opinions on this issue. Some say that you are risking the lens delaminating due to the groove interfering with the polarized filter. Others say that this area is so thin that it is negligible in the real world. Well a coworker of mine called me on dispensing these glasses, basically saying I should have chosen another frame for this person. I personally have never had a customer return with a delaminated polarized lenses in a semi rimless frame. I'm sure it's happened, but never to me. I would appreciate any opinions you might have.
Groove placement is key. With a polarized sun lens in a regular frame you should put the bevel as close to the front of the lens because if you dont the lens will stick out the front of the frame and look awkward. Placing the bevel on the front will insure that the sunglass look as the Cx expects that it should. With a grooved metal frame or grooved nylor frame you would think that the rationale would be the same except where you would put the bevel thats where you put the groove, but if you do this you will increase the chances that the lens will delaminate at the polarizing filter. The key is placing the groove slightly behind the polarizing filter, so that the groove doesnt interfere with the polarizing filter and cause delamination. Sometimes this doesnt look great because the polarizing filter gives the lens its color, and you may get distracting edge/front reflections that the Cx may not like. Some opticians wont sell a polarized lens in these kinds of frames (sometimes photochromic lenses too) because these considerations are too fraught. Hope that helps.
Optical Cross: n. crucifixion apparatus used by the New Jersey State Board.
"It is not knowing, but the love of learning, that characterizes the scientific [person]." -Charles Sanders Peirce
"A concept is a brick. It can be used to build a courthouse of reason. Or it can be thrown through the window. -Gilles Deleuze
Moving the groove back close to 50/50 or 40/60 wont make rings like it would on a beveled lens, because the bevels being clear are what cause them. Should be ok with modern polar lenses because they have the filter very close to the front in my experience
With the exception of CR39 and 1.67, which are typically 0.8 to 1.0 from the front. Then again, if you insist on CR39 in a nylor, you shouldn’t be practicing opticianry.
Don, back in the day when we didn’t have Trivex and Poly really sucked, there wasn’t much of a choice. Patients seemed to take better care of their eyewear back then, as well. We made facets and drills in CR39 with minimal returns. Heck, we even did drills and grooves in glass.
With insurance and generous return/redo policies, thanks to the big box stores, patients do not take care of their glasses like they used to.
This is why opticians should steer patients away from CR in groove mounts.
You and your personal experience, along with all of us and ours, are not comparable to the general public.
If nothing else- it comes down to subconscious mindset. Signatures are required for CR39 in a groove- because the general public can ALWAYS claim they didn't know better otherwise.
Have I told you today how much I hate poly?
speaking of back in the day, i used a cutting wheel attached to a flexible shaft motor which was a mainstay in most offices. i could place the groove at any position and depth needed. i even grooved executive bifocals and was able to place the majority of thickness toward the back.
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