So I assume then that the lens designs that go onto the Camber lens blank are pretty much subject to availability depending on which lab creates them for us?
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AFAIK only IOT designs are available for the Camber blank. Your lab can pick and chose which IOT designs they want to offer on the camber blank. One of the wholesale lab guys here might have a better insight into that part.Comment
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And , of course you all know, there is an improved version of camber called Power.At least that's what Walman calls it.The Power Plus incorporates POW and can be specified to concentrate on near or dist. So far we've had prev prog failures adapt to this well.Comment
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Primarily a lens for moderate to high hyperopia with moderate to advanced/absolute presbyopia. Here's why...Originally posted by bretk0923 View Post
Single-progressive spectacle lenses and also double-progressive spectacle lenses are known from the prior art. For example, U.S. Pat. No. 6,089,713 (=DE 197 01 312) describes a spectacle lens having a spherical front side and multifocal rear side, and also a method for producing it. Published German patent application no. DE 33 31 757 A1 describes a progressive spectacle lens having a convex aspheric front surface and concave aspheric inside or rear surface.
However, it has been found in the case of spectacle lenses having progressive rear surfaces that in the stronger addition area the spherical front surfaces must be fashioned with more of a curve than the front surfaces in the distance area of lenses having progressive front surfaces. This is felt to be disadvantageous by the spectacle wearer both for optical and for cosmetic reasons. The reason for this resides in the geometry of the lenses: if, for example, a lens is designed with a distance area effect of +5 dpt, in the case of progressive front surfaces use is made, for example, of a front surface with a surface dioptric power of +7 dpt which rises in the near area to approximately +10 dpt if the lens is to have an addition of 3 dpt. The spherical rear surface then has a surface dioptric power of approximately −2 dpt, resulting in an effect of approximately +5 dpt in the distance area.
If, in the case of progressive rear surfaces, a spherical front surface is to be selected which is as flat as the distance area of the lens with a progressive front surface (that is to say 7 dpt), the rear surface would need to have a surface dioptric power of −2 dpt in the distance area. With progressive rear surfaces, the mean curvature needs to decrease from the distance area to the near area and not, however, to increase such as would happen with progressive front surfaces. Thus, the surface dioptric power must rise from −2 dpt by 3 dpt to +1 dpt, in order to effect an addition of 3 dpt. This form of surface configuration is termed reversal of curvature. The surface is no longer only concave, as is the case with conventional products, but has an S-shaped course in a vertical section.
However, rear surfaces with reversal of curvature exhibit specific wearing properties which can lead to problems for the spectacle wearer. One problem is the relative nearness of the rear surface to the eye when such lenses are countersunk in conventional mounts. Since the eyelashes then strike against the lens, this frequently leads to irritation. A further problem is the more frequently occurring reflections which have a disturbing effect and reduce the contrast during seeing.
In order to avoid these effects, it is possible to increase only the curvature of the front surface in the case of lenses with a progressive rear surface, but this entails lenses which are thicker and unattractive cosmetically. Again, this raises the intrinsic magnification of the lenses, the result of which is to intensify the so-called “cow-eye effect”.
Decreased magnification, thickness, and weight, compared to full backside progressive lenses that have a spherical front surface.
Hope this helps,
Robert MartellaroScience is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
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Robert,have you personally tried the camber? I have and am a high minus. I find it superior in int and near compared to Zeiss GT2 3D and the old Individual 2 ( I understand it's been re formulated}? It's similar to the new Physio W3, at least for me. I am going to try new power shortly.Comment
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I have the Camber and prefer it to my Kodak Uniques. I have same Rx and same frame for both, and prefer the Camber...crisper near.Comment
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Robert - That's a level of detail beyond what I was looking for. Awesome stuff. Really gives a nice refresher on why the theory on this lens is so solid, so thank you for that.
Still in search of some negative feedback, which I'm slowly becoming more and more convinced that such feedback does not exist...Comment
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This isn't really anything new with Camber. Camber is only the lens blank the designs are cut on. The "Power Plus" distance/intermediate/near are the three different designs from IOT, the ALPHA H65/H45/H20 respectively cut on a camber blank. The regular "Power" lenses seem to be the same lenses cut on spherical front blanks. and the power lite are probably from the IOT basic series designs. All the IOT designs can be found here.Originally posted by rdcoach5 View PostComment
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No, not for me...I want the best distance with the highest near zone, with no concern for intermediate utility due to the frequent use of separate task eyeglasses.Originally posted by rdcoach5 View Post
I haven't had a juicy presbyopic mod to high hyperope recently to use as guinea pig, but next chance I get I'll try it and report back. Hopefully it will be for someone who has had little or no change in Rx.
I would probably find the distance unacceptable with the near bias design, and the near unacceptable with the distance bias lens.Originally posted by bretk0923 View Post
Younger describes a slice of front surface using the term "elephant's trunk", but only use somewhat general terms to describe the practical advantages, primarily limited to flatter base curves and reduced magnification for hyperopes, without the need for high chroma/high refractive index materials. I don't see any advantages over other first-rate PAL designs for low plus and minus Rxs.
Hope this helps,
Robert MartellaroScience is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
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Since the beginning of the new year I have dispensed 12 camber PALS: The first was for a gentleman who had tried Progressives a couple of times but hated them. I did these as poly Drive wear. He put them on and with a big grin gave the the thumbs up sign. He left delighted. I phoned him 4 weeks later and he was still delighted.
a couple of weeks later. a lady, a new customer, who had worn PALS for a long time but said she was never really felt fully comfortable with them, went with my advice and tried these.
in 1.6 Transitions. On fitting, she looked up with a startled look; I thought Ho Ho, problem? She said she felt that she was not wearing lenses at all and was over the moon. She came back a week later. I thought I had a problem and as I had a shop full of clients was a little worried that she was going to complain. She said " I just had to come ad tell you that these are the best lenses I have ever had. I did another pair for a guy who heard that conversation; on pick up he said they were brilliant. Since then a further nine dispenses of these including a guy with +8.00 OU Dist . " Great".
I have had phone calls from wearers to tell me how good they are.
I pay close attention to Panto and wrap and over +/- 3.00 measure BVD carefully.
In the UK we can get all the Materials: Trivex, 1.5. and polarised, Drivewear, but not in 1.74 index.
I am very happy with this lens.Comment
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For me, the new Power is better fot int/near than anything else I've tried which includes Physio W3 , any Zeiss or UniqueComment
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Which version, rd?Comment
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