Frames do not fit anymore!

[Jacques]

I recently bought the following sport sunglasses with prescription lenses:

http://www.rodenstock.com/rod_web/co...0/40/16509.xml

When I tried the frames with normal standard lenses the frames did fit very well on my narrow and long face (the frames were "curvy enough" to follow the shape of my head). However, once my optician installed the prescription lenses on the frames, the perfect is fit seems to be gone; the frames are no longer 'curved" but look straight. In fact, they look silly (like Elton John's frames in 1970s) as they no longer follow the shape of my head.

1. What explains the diffedence?

Someone told me that the frames must be "heated" so that they can be "re-adjusted" on my face, to follow the shape of my head. He also mentioned that the re-adjustement (by heating) could be a rather demanding task and many optician try to avoid it, unless the customer specifically requests.

2. Can the frames be re-adjusted like they were before?

[chip anderson]

Unless the opticians installed lenses that are flatter in curvature than the lenses that were in them prior to purchase (demo lenses) they can be adjusted (heated and bent) to the origional shape. Many times the lab will heat the frame to install new lenses and cause the frame to be flattend out.


Chip

[Chris Ryser]

You being in Europe, you should be able to find an optician that has no problem to adjust the frame as you want it. Plastic frames are easily adjustable when heated and any good optician is fully qualified to do that.

[QDO1]

possibly the lenses need to made with a more curved form. This is not a definitive answer, as that approach is very prescription dependant.

That frame, from experience is a swine to adust on the front. an experienced Optician with a frame heater is the only way it will be fitted

what is your prescription?

[Chris Ryser]

...............................an experienced Optician with a frame heater is the only way it will be fitted

I just hope for the sake of this profession.....................that there not one optician that does not have a frame heater, expierienced or not.

[Jacques]

possibly the lenses need to made with a more curved form. This is not a definitive answer, as that approach is very prescription dependant.

That frame, from experience is a swine to adust on the front. an experienced Optician with a frame heater is the only way it will be fitted

what is your prescription?

I will go and visit my optician on Monday. However, I do not understand why did he heat the frame to install new lenses, which caused the frame to flatten out?

I have -2.25/-2.75 (Hoya index w/ 1.6).

[QDO1]

I will go and visit my optician on Monday. However, I do not understand why did he heat the frame to install new lenses, which caused the frame to flatten out?

I have -2.25/-2.75 (Hoya index w/ 1.6).

Basically the lenses that come out of the frame are quite curved. your prescription (-2.25-2.75) in the hoya lens you mentioned will be quite flat in comparison. this will result in the Glazer having to strighten the frame to match the lens, resulting in the sides being splayed out

there are 2 routes to sorting this out. Re-make the job with a more curved version of your lens, and compensate everything to do with the lenses to cope with the extra curve applied, or re-fit the frames. Neither is a great option. But cleverly done the first option would be the best one. I would hazard a guess and say that the lens power is out of range for Rodenstock to glaze the job themselves.. which might suggest something to you

[QDO1]

the frame has to be heated, because heating the plastic makes it more flexible, allowing the lens to be inserted. when the frame cools, it becomes more rigid, holding the lens in firmly

[High_Abbe]

I will go and visit my optician on Monday. However, I do not understand why did he heat the frame to install new lenses, which caused the frame to flatten out?

I have -2.25/-2.75 (Hoya index w/ 1.6).

A competent optician would have discussed this with you prior to the sale.

[Jacques]

Hi!

My optician replaced the Hoya index lenses by the std. demo lenses and, voila, the frames were curvy again!!!

He explained that the frames (especially the bridge) are so flexible that the lenses have a big impact on the shape of the frames:

- the Hoya index lenses are not curvy so the frames flatten out,
- the std. demo lenses are curvy so the frames also remain curvy.

I agree with High Abbe's message above, which suggests that a competent optician would have discussed this with you prior to the sale. I consider that it would have been his responsibility to advice me. Any suggestions for the next step? What would be a fair deal?

[William Stacy O.D.]

I can't understand why labs don't put a curve in the bevel of a flat lens. With minus lenses you have plenty of edge to run that bevel apex from near the back surface of the 180 meridian to near the front surface at the 90 to approximate the curvature of the original curve of the frame. What is so tough about that????

[Trevor D]

I can't understand why labs don't put a curve in the bevel of a flat lens. With minus lenses you have plenty of edge to run that bevel apex from near the back surface of the 180 meridian to near the front surface at the 90 to approximate the curvature of the original curve of the frame. What is so tough about that????

I don't think it's tough to do but it ends up looking a bit strange as the edges will stick out the front of the frame whilst the top and bottom will be relatively hidden. Optically, of course it's preferable to grinding minus powers on high bases. This is where the Sola Spazio and Oakley's wrap rx lenses should come into play (I'm dying to get a chance to use either!)

T

http://www.optopia.com.au

[William Stacy O.D.]

I don't think it's tough to do but it ends up looking a bit strange as the edges will stick out the front of the frame whilst the top and bottom will be relatively hidden. Optically, of course it's preferable to grinding minus powers on high bases.

But we're talking here about sport glasses or sunglasses where it shouldn't make much difference, as opposed to clear dress glasses...

But I'm glad to hear it's not tough to do. How would I order it? Something like "use a 6 base bevel on these 3 base lenses" or something like that?

[Trevor D]

I've glazed similar to what we are talking about here but as far as ordering them from a lab I have no clue how you would word it!!! The way you put it seems ok to me although you could definitely expect a phone call from the lab as soon as they received your order!

Good point about them being for sports and not a fashion item

[QDO1]

I can't understand why labs don't put a curve in the bevel of a flat lens. With minus lenses you have plenty of edge to run that bevel apex from near the back surface of the 180 meridian to near the front surface at the 90 to approximate the curvature of the original curve of the frame. What is so tough about that????

not tough for you or me perhaps, but the modern younger button pushing robotized de-skilled workers that most labs use - far beyond thier capabilities

[QDO1]

i would do the job in a 1.6 plastic tintable material, specify the base curve and adjust for position of wear. that deals with the RX properly, deals with the cosmesis in terms of curve and thickness. the 1.6 is a nice comprimise on ABBE etc

[rinselberg]

i would do the job in a 1.6 plastic tintable material, specify the base curve and adjust for position of wear. that deals with the RX properly, deals with the cosmesis in terms of curve and thickness. the 1.6 is a nice comprimise on ABBE etc

I checked out the link that was provided (in the very first post, above) to these Rodenstock sports frames. They appear to be fairly high-tech, in terms of their "sportiness". Wouldn't there be an inclination to say that the greater impact resistance of poly or trivex (vs. 1.6 plastic) is more or less "required", in keeping with the "sporting" application?

Just for the sake of discussion, anyway ...

[JerryR]

This seems to be the ideal situation for the type of lenses that Awtech talks about. Using a 6 or 8 base lens for a higher minus Rx in a wrap type frame, that will provide desired cosmetic look and fit as well as great optics.

[Ed_Optician]

Ran into a situation related to this years afo. Menrad metal frames were built like a piece of the Brooklyn Bridge you could not increase the curve or flatten out a rim without distorting the eyewire. My solution eas to put a bevel on the lens to match the frame. I put a 6bc bevel on a Planpo base lens worked like a charm....used an optronics Horizon II to do that with today's patternless machines it is even easier to do so


Ed

[SpecialT]

My solution eas to put a bevel on the lens to match the frame. I put a 6bc bevel on a Planpo base lens worked like a charm....

Didn't the front of the lens stick out of the front of the frame? I can understand a little extra curve on the bevel, but my experience is that cosmesis can be an issue. I know it requires more work, but surfacing a higher base curve seems to be a superior option.

[QDO1]

I checked out the link that was provided (in the very first post, above) to these Rodenstock sports frames. They appear to be fairly high-tech, in terms of their "sportiness". Wouldn't there be an inclination to say that the greater impact resistance of poly or trivex (vs. 1.6 plastic) is more or less "required", in keeping with the "sporting" application?

Just for the sake of discussion, anyway ...

thats a good point. there is a balance between optics, mechanical stability, saftey and cosmesis. the dispensers lot is to get the right (or best possible) balance. in some environments the saftey consideration is over-riding

[Ed_Optician]

There is a balance between cosmetically pleasing and good optics. My case was a high minus around -9.00 in thet time frame 1.56 index was what was available to me. I surfaced it as thin as possible, did what I could with the bevel fitting optician wanted a 1/3 2/3 bevel this was better interms of not distorting the frame....patient insisted on edge coating as wel as AR coat. THe patient wanted the best vision possible cosmetics were of secondary importance

Ed

[SpecialT]

I follow you Ed Optician and it is a good point that when cosmesis is the only consequence, always give the patient what they want! Also, when within reason, do the best you can with what you got!

:cheers: