-
The BladeForums.com 2024 Traditional Knife is available! Price is $250 ea (shipped within CONUS).
Order here: https://www.bladeforums.com/help/2024-traditional/
sunglasses
- Thread starter =Voodoo=
- Start date
- Joined
- Mar 20, 1999
- Messages
- 7,497
Right now still wearing my Revo Extreme Wrap....freaking great comfortable glasses. Will probably be switching over to Oakley polarized juliet this summer to see how they perform.
- Joined
- Mar 23, 2000
- Messages
- 3,769
I've heard that a major reason for "plastic" (it's almost unfair to call it "plastic" when it's so incredibly high tech!) is related to noticeably reduced weight. For sunglasses with glass lenses, the lenses can get away with being thinner than Rx lenses because there is no added curve for Rx correction. I'm sure there might be other reasons for going plastic besides the weight issue, but I don't know any of them. The many advancements in the plastics lenses have been so amazing that I wouldn't be surprised if the quality has surpassed glass lenses.
My eyes are fairly bad, so the lenses get thicker to compensate. Thank goodness there are newer "high-index" lenses that are plastic and are much thinner than their standard plastic siblings.
Also of note, there are restrictions with the type of frames one can have if one is getting a pair of Rx sunglasses. No "wrap-around" frames. It's just impossible to curve Rx lenses to wrap around the side of the face. If you look at my Costa Del Mar pair over a dozen posts up, I was told that those frames were about as "curved" (wrap-around) as they could go...which is not very much. I'm not a fan of the extreme wrap-around ones (like those in the first two posts), but I need as much protection covering my eyes as possible.
Personally, with my extreme eye sensitivity, buying a separate pair of Rx sunglasses is absolutely worth the cost and added problem of carrying and switching glasses regularly.
Personally, I hate the "transition" lenses for two reasons. First, I really like my primary glasses to be 100% clear...no hint to tint. Though optometrists say that they go clear, the ones I've seen don't go clear enough and the transition period when going indoors is not acceptable. Second, I need dark sunglasses with strong polarization when outside. The transition lenses just don't get dark enough, providing the level of protection I require. My Rx sunglasses actually have extra coatings of polarization, including a coatings on both sides of the lenses (I don't know the specifics, but I think there's two coatings on the outside and one on the inside...maybe just one coating on each side...I can't remember what they did, but it was very much out of the ordinary and a special order scenario).
I'm drooling over the new eye correction surgery available. My insurance will cover some of it and the rest provide tax benefits (that's a long story...I think it's called a cafeteria plan through my wife's employer). Maybe in the next year or two.
Hope this has been helpful.
My eyes are fairly bad, so the lenses get thicker to compensate. Thank goodness there are newer "high-index" lenses that are plastic and are much thinner than their standard plastic siblings.
Also of note, there are restrictions with the type of frames one can have if one is getting a pair of Rx sunglasses. No "wrap-around" frames. It's just impossible to curve Rx lenses to wrap around the side of the face. If you look at my Costa Del Mar pair over a dozen posts up, I was told that those frames were about as "curved" (wrap-around) as they could go...which is not very much. I'm not a fan of the extreme wrap-around ones (like those in the first two posts), but I need as much protection covering my eyes as possible.
Personally, with my extreme eye sensitivity, buying a separate pair of Rx sunglasses is absolutely worth the cost and added problem of carrying and switching glasses regularly.
Personally, I hate the "transition" lenses for two reasons. First, I really like my primary glasses to be 100% clear...no hint to tint. Though optometrists say that they go clear, the ones I've seen don't go clear enough and the transition period when going indoors is not acceptable. Second, I need dark sunglasses with strong polarization when outside. The transition lenses just don't get dark enough, providing the level of protection I require. My Rx sunglasses actually have extra coatings of polarization, including a coatings on both sides of the lenses (I don't know the specifics, but I think there's two coatings on the outside and one on the inside...maybe just one coating on each side...I can't remember what they did, but it was very much out of the ordinary and a special order scenario).
I'm drooling over the new eye correction surgery available. My insurance will cover some of it and the rest provide tax benefits (that's a long story...I think it's called a cafeteria plan through my wife's employer). Maybe in the next year or two.
Hope this has been helpful.
Ron Andersen said:
There is NO eveidence of optical superiority of plastic (hi-tech or not) over glass.
Otherwise we'd be seeing a lot more camera lenses, binoculars, and other optical instruments using plastic lenses.
Plastic is superior in safety and weight -
they can also be made into shapes that cannot be made easily in glass -
so that more fashionable and good looking sunglasses can be made using plastic.
So plastic is also superior for shaping and in fashion/looks.
BUT as far as I can tell they are NOT optically superior.
and I am not being rude -
who really wants to listen, or be told, that their $$$hundred$ "hi-tech" sunglasses may be optically INferior to older fashioned glass lenses?
I know I wouldn't.
--
Vincent
http://UnknownVT.cjb2005.net
http://UnknownVT.cjb.net
http://UnknownVincent.cjb.net
Most people buy sunglasses based on marketing hype rather than optical quality. Sunglasses have to be one of the most overpriced products in the world based on the actual manufacturing cost for most models. With Oakley, for instance, you mainly pay for their advertising.
Anyway, ask the average dude why he bought a $200 pair of sunglasses and he'll probably say "because they look cool" if he's being honest. The functionality is almost always secondary for most buyers.
Glass is optically superior, but I have no problem with a well-made polycarbonate lens. A pair of sunglasses has only one lens element, and unless they're prescription, they don't have to do any refraction or anything. Binoculars and camera lenses have tons of lens elements, so it's exponentially more important to use a material with good optical properties. I'm not sure about binoculars, but many very good camera lenses incorporate a few plastic elements.
I have several pairs of decent sunglasses and I honestly can't say that I notice any optical advantage to glass. I'll tell ya what, though... glass is way harder to scratch. Anyway, for sports I wear plastic lenses, and I usually drive with my favorite glass-lensed pair, but that's mainly because they have the best polarizing.
Anyway, ask the average dude why he bought a $200 pair of sunglasses and he'll probably say "because they look cool" if he's being honest. The functionality is almost always secondary for most buyers.
Glass is optically superior, but I have no problem with a well-made polycarbonate lens. A pair of sunglasses has only one lens element, and unless they're prescription, they don't have to do any refraction or anything. Binoculars and camera lenses have tons of lens elements, so it's exponentially more important to use a material with good optical properties. I'm not sure about binoculars, but many very good camera lenses incorporate a few plastic elements.
I have several pairs of decent sunglasses and I honestly can't say that I notice any optical advantage to glass. I'll tell ya what, though... glass is way harder to scratch. Anyway, for sports I wear plastic lenses, and I usually drive with my favorite glass-lensed pair, but that's mainly because they have the best polarizing.
- Joined
- Oct 17, 2001
- Messages
- 21
You Have To Love Oakleys For Fit And Finish. The Only Problem That I Have With Them Are Stress Cracks In The Lenses. I Probably Have Fifteen Differnt Styles And The Majority Seem To Have These Small Cracks In The Lenses. Anyone Else Have This Problem With Them?
- Joined
- Mar 23, 2000
- Messages
- 3,769
Hey Vincent,
I don't know for certain which is superior and if I had to make a gut guess on which is truly "better" (of higher visual quality), I'd side with glass. To quantify "better," though, might require adding up a number of issues, such as strength, durability, etc., not just visual quality.
I certainly didn't take your reply as being "rude," but I felt I was misunderstood...thus the response.
I don't know for certain which is superior and if I had to make a gut guess on which is truly "better" (of higher visual quality), I'd side with glass. To quantify "better," though, might require adding up a number of issues, such as strength, durability, etc., not just visual quality.
Hopefully from my overall post, readers walked away with two things:UnknownVT said:
- That I am not an expert in this field and do not have either scientific or intimate knowledge
- That a firm declaration that plastic lenses HAVE surpassed glass lenses in superiority was not made.
I certainly didn't take your reply as being "rude," but I felt I was misunderstood...thus the response.
DOUG APPLEGATE said:
I Personally Find That The Fit And Finish Is Nothing Special On Oakley Sunglasses. No Stress Cracks To Report, Though.
Isn't it a pain to capitalize the first letter of every word? This link might be handy for you.
- Joined
- Oct 17, 2001
- Messages
- 21
I've Tried Everything From Rayban To Revo, The Oakleys Are Packaged Right And Feel Good On Right Out Of The Box. The Only Problem That I Have With Them Are The Stress Cracks In The Lenses. I Don't Capitalize All The Letters It Just Comes Out That Way.
Cougar Allen
Buccaneer (ret.)
- Joined
- Oct 9, 1998
- Messages
- 76,399
Most of the confusion here is vague thinking -- thinking in terms like "optically superior" and "better" without defining them.
Glass is harder and more brittle. Polycarbonate is tougher and softer. Those are clear measurable properties. "Better" is not so clear, not until you narrow that down to better for what purpose. For astronomical purposes brittleness doesn't matter -- you can manufacture low-expansion glass telescope mirrors and you won't have to pay out millions of dollars when they break and blind your customers. "Optically superior" ... well, if you're making telescope mirrors all you need is a polishable substance that will hold stable dimensions through a range of temperatures. It doesn't even have to be transparent. The substance that expands and contracts least with changes in temperature is the most superior for that optical purpose. That isn't a problem in sunglasses at all; the desirable properties are entirely different.
People complain when their glasses get scratched. They sue when their glasses break and blind them. I understand it's practically impossible to buy glass eyeglasses in the US these days -- no matter how much money you offer, the amount you could sue for if they break and blind you is the greater....
Glass is harder and more brittle. Polycarbonate is tougher and softer. Those are clear measurable properties. "Better" is not so clear, not until you narrow that down to better for what purpose. For astronomical purposes brittleness doesn't matter -- you can manufacture low-expansion glass telescope mirrors and you won't have to pay out millions of dollars when they break and blind your customers. "Optically superior" ... well, if you're making telescope mirrors all you need is a polishable substance that will hold stable dimensions through a range of temperatures. It doesn't even have to be transparent. The substance that expands and contracts least with changes in temperature is the most superior for that optical purpose. That isn't a problem in sunglasses at all; the desirable properties are entirely different.
People complain when their glasses get scratched. They sue when their glasses break and blind them. I understand it's practically impossible to buy glass eyeglasses in the US these days -- no matter how much money you offer, the amount you could sue for if they break and blind you is the greater....
Cougar Allen said:
Serengeti sunglasses (USA) are made from Optical Glass -
and they boast about it....
Serengeti Eyewear Technology - Optical Glass
QUOTE:
OPTICAL GLASS
Made from distortion-free, precision ground and polished optical glass, Serengeti sunglasses give you the clearest image available. Scratch resistant and chemically tempered for strength, each and every lens is drop ball tested with a steel ball to ensure maximum impact resistance. With proper care, Serengeti lenses can last a lifetime
UNQUOTE
It also appears that Pearle Vision - the largest retailer in the US of eyeglasses still use glass as one of their lens material choices -
Eyeglass Lens material choices at Pearle Vision
QUOTE:
Glass
Glass is the original lens material and can accommodate the widest range of prescriptions. Glass also features great, natural scratch-resistance along with long-lasting lens clarity. Tints and coatings can also be added to better suit your particular lifestyle.
UNQUOTE
The US Air Force specs their sunglasses with N-15 glass lenses -
USAF Flight Surgeon's Guide: Chapter 8
(about 1/4 way down the page)
QUOTE:
Selection of a Sunglass for U.S. Air Force Use
Selection of the best sunglass lenses for U.S. Air Force use has taken the above factors into consideration. After much research by the USA, USN, and USAF, it has been determined that a neutral-gray lens with 15 percent transmission is most suitable for the level of brightness encountered in flying. All invisible electromagnetic radiation is virtually eliminated by this lens. A transmission curve for the standard N-15 USAF sunglass is shown in Figure 8-5.
Figure 8-5. Transmission Curve of the Standard N-15 sunglass lens.
Glass N-15 lenses eliminate most of the abiotic wavelengths below 350 nanometers and approximately 80-85 percent of the longer UV between 350 and 400 nm. However, fluorescence of the crystalline lens may present a problem at high altitudes, when lenses are used which transmit light in the region of 360 nanometers. Infrared rays are much more effectively attenuated by the presently available neutral lens than by any of the colored lenses or the reflecting lenses. The ability to recognize colors without any impairment occurs only with neutral lenses--either absorbing or reflecting types. Colored lenses distort colors. The neutral absorbing lens is superior to the neutral reflecting lens because the reflecting lens transmits infrared rays and because the reflecting coat is susceptible to damage.
UNQUOTE
Some "clarity" on Glass -
LOOKING AT GLASS - ask the Labs @ Eyecare Business
QUOTE:
Q Is glass still considered to be the best lens material for visual clarity and acuity?
--Barry Edewaard, OD,
Blountstown, Fla.
A: Glass lenses are still the best when it comes to visual acuity and clarity. This is due in part to two characteristics: Hardness and rigidity.
The hardness of glass allows lenses to be ground and polished to a finer surface, that even under extreme magnification is free from variations in curvature that are often present in plastic or poly lenses. These variations can create distortions as light passes through the lens surface.
The rigid nature of glass allows lenses to be produced that will not deform from eyewire tension or temperature extremes. Plastic and poly lenses can alter from eyewire tension or day-to-day changes in temperatures, altering the prescribed power. The thinner the lens, the more noticeable the deformation.
Temperatures necessary to deform glass lenses would cause plastic or poly to burst into flames.
Glass lenses are still the standard for quality telescopes, binoculars, microscopes, and cameras.
--Dennis Tindall,
Vision Systems, Inc.
UNQUOTE
--
Vincent
http://UnknownVT2005.cjb.net
http://UnknownVT.cjb.net
http://UnknownVincent.cjb.net
While I like my Oakley Mars for their sheer amount of titanium, their weirdness and the fact that I can adjust them with the same torx bit I use for my knives, I must also say that their fit and finish is downright crude, with very uneven surfaces, and a horribly primitive "mechanism" for keeping the frames locked around the lenses. They are a far cry from the probably computer generated, idealized images one can see on Oakley´s website.
Kristofer
Kristofer
- Joined
- Oct 28, 2003
- Messages
- 303
Ok,
There seems to be a valid argument for glass being optically superior.
My next question would be about safety. Who out there needs/demands that safety be just as important, if not more, as being optically superior? Serengeti describes a "steel ball drop test"...is that worth a damn? Realistic impact forces are not described...just wondering if this test is up to real world encounters for hunters, motorcycle wearers etc..Maybe it is... just want to know...
Also curious about polarization. Are the newer polarization technigues, i.e. Oakleys 'infusion' process superior to what can be done with glass? When lenses are polarized, do glass or plastic lenses benefit more and which takes the most advantage of this polarization? In other words...which type of lens offers the best 'true' polarization regardless of process?
There seems to be a valid argument for glass being optically superior.
My next question would be about safety. Who out there needs/demands that safety be just as important, if not more, as being optically superior? Serengeti describes a "steel ball drop test"...is that worth a damn? Realistic impact forces are not described...just wondering if this test is up to real world encounters for hunters, motorcycle wearers etc..Maybe it is... just want to know...
Also curious about polarization. Are the newer polarization technigues, i.e. Oakleys 'infusion' process superior to what can be done with glass? When lenses are polarized, do glass or plastic lenses benefit more and which takes the most advantage of this polarization? In other words...which type of lens offers the best 'true' polarization regardless of process?
wsyocum said:
Generally plastic is thought to be safer than glass - simply because plastic is less likely to shatter.
BUT beware plastic can shatter and shard as well.
The drop-ball test is actually a standardized FDA impact test,
and not something invented for marketing.
You might want to read this article -
Testing For Toughness - A Fresh Look at Safety and Lens Materials
Plastic if it is too thin will fail this drop-ball test too.
Also although some plastics lenses will pass the "test" they are actually damaged to the point of being useless after the test.
QUOTE:
LENS TESTING
Drop-ball testing a plastic lens can mar the surface and always risks damaging the lens. It's especially a problem with AR-coated lenses when as the steel ball strikes, it creates a small star fracture in the AR coating at the point of impact, large enough for the patient to notice. The lens has passed the drop-ball test, but it has been destroyed in the process.
For AR-coated stock lenses, this is not a problem. The manufacturer batch tests them. From every batch of 1,000 or so, they pull and test a certain number of lenses, discarding them after testing.
What constitutes failure? The FDA defines a lens has failed the drop-ball test when:
The tested lens breaks into two or more pieces.
Particulate matter is expelled from the backside of the lens.
Star fracturing of the AR coating does not constitute failure, so AR-coated stock lenses that do not break during batch testing meet the FDA requirement. If a representative number of lenses from a batch are tested without failing, the entire lot is said to meet FDA standards.
UNQUOTE
What really surprised me was this:
QUOTE:
INDUSTRIAL EYEWEAR
Even in the field of industrial eye safety--where it might be presumed that polycarbonate would become the standard--it did not take over the safety market. There appear to be two reasons for this. The first is cost and the fact that industrial safety contracts are often driven by price. This is understandable when a manufacturing company is responsible for providing safety glasses for thousands of people. Simply put, glass lenses are less costly than polycarbonate, and, thanks to economics, glass still plays a prominent role in industrial safety glasses.
UNQUOTE
So in some cases glass can be "superior" in safety too - something to (vaguely
) think about, huh?--
Vincent
http://UnknownVT2005.cjb.net
http://UnknownVT.cjb.net
http://UnknownVincent.cjb.net
- Joined
- Oct 28, 2003
- Messages
- 303
VT,
Cool. Thanks for the info.
I would like to add that "safe", IMO, is not having shards of glass or plastic, not to mention the "projectile", in my eye. If the lens is rendered no longer useful...no problem...as long as I'm not blind. Any idea on what is the comparison of plastic vs. glass as to which has the higher % of passing these tests?
As to the blurb on "cost" factor...glad I don't have to rely on an employer to make that decision for me.
Cool. Thanks for the info.
I would like to add that "safe", IMO, is not having shards of glass or plastic, not to mention the "projectile", in my eye. If the lens is rendered no longer useful...no problem...as long as I'm not blind. Any idea on what is the comparison of plastic vs. glass as to which has the higher % of passing these tests?
As to the blurb on "cost" factor...glad I don't have to rely on an employer to make that decision for me.
Kohai999
Second Degree Cutter
- Joined
- Jul 15, 2003
- Messages
- 12,554
It comes down to one issue: Glass lenses don't scratch as easily as plastic ones.
I was scratching the shnizzit out of the plastic lenses that I had. I have a great optical person at Lenscrafters, but the replacement costs were killing me, 3 sets of lenses in two years at $100+ per changeout. This is WITH anti-scratch coating.
Once I switched to glass, no more scratching. I have dropped my glasses a few times and have had no problems with breakage.
I got a pair of Ray Ban glasses in December, and had the polarized glass lenses put in. It was a pain, because of the curvature, and they lost the first set of glasses, so it took 3 weeks, but it is totally worth it. We get a lot of glare on the roads in SoCal, and the polarizing works wonderfully to intensify contrast while driving, which is most of the time that I wear sunglasses. I have also been told that glass lenses are much better at blocking UV, but that could entirely be a myth.
I tend to scratch my lenses while working in the garage on knives and such, and the glass lenses have solved that problem. I realize that shattering lenses are not a good thing, but that is a concern with plastic as well. The upside just completely obliterates the downside at this point.
Best Regards,
STeven Garsson
I was scratching the shnizzit out of the plastic lenses that I had. I have a great optical person at Lenscrafters, but the replacement costs were killing me, 3 sets of lenses in two years at $100+ per changeout. This is WITH anti-scratch coating.
Once I switched to glass, no more scratching. I have dropped my glasses a few times and have had no problems with breakage.
I got a pair of Ray Ban glasses in December, and had the polarized glass lenses put in. It was a pain, because of the curvature, and they lost the first set of glasses, so it took 3 weeks, but it is totally worth it. We get a lot of glare on the roads in SoCal, and the polarizing works wonderfully to intensify contrast while driving, which is most of the time that I wear sunglasses. I have also been told that glass lenses are much better at blocking UV, but that could entirely be a myth.
I tend to scratch my lenses while working in the garage on knives and such, and the glass lenses have solved that problem. I realize that shattering lenses are not a good thing, but that is a concern with plastic as well. The upside just completely obliterates the downside at this point.
Best Regards,
STeven Garsson
You are making an assumption that glass is UNsafe - it is obviously NOT.wsyocum said:As to the blurb on "cost" factor...glad I don't have to rely on an employer to make that decision for me.
The point was that glass is used for OSHA mandated industrial SAFETY eyewear (that surprised me too).
This means they pass the relevant ANSI standard.
QUOTE:
When it comes to eye protection, the United States is unique. This is the only country that mandates minimum impact protection for spectacle lenses.
UNQUOTE
The current eyewear safety standard is
ANSI Z87.1-2003
Comparison of old ANSI Z87.1-1989 and new ANSI Z87.1-2003
There are TWO levels for safety glasses - basic and high impact - UNLESS eye wear is marked as ANSI Z87.1-2003 they are NOT compliant - that means we are assuming just because the lens is polycarbonate or some hi-tech plastic they are safe (that's a very dangerous thing to do when it comes to safety)
So let me ask this - which of the hi-tech high$$$ plastic/polycarbonate sunglasses are actually marked as ANSI Z87.1-2003 - or advertize that they pass either ANSI Z87.1-2003 or FDA tests?
At least the Serengeti glass sunglasses pass a drop-ball test.......
from ANSI Z87.1-2003
QUOTE:
1. Two Levels of Protection:
Basic and High
LENSES: The new standard designates that lenses will be divided into two protection levels, Basic Impact and High Impact as dictated by test criteria.
Basic Impact lenses must pass the drop ball test, a 1" diameter steel ball is dropped on the lens from 50 inches.
High Impact lenses must pass high velocity testing where 1/4" steel balls are shot at different velocities.
Spectacles: 150 ft./sec.
Goggles: 250 ft./sec.
Faceshields: 300 ft./sec.
UNQUOTE
--
Vincent
http://UnknownVT2005.cjb.net
http://UnknownVT.cjb.net
http://UnknownVincent.cjb.net