Page 3 of 4 FirstFirst 1234 LastLast
Results 51 to 75 of 76

Thread: Essilor's Prevencia vs Hoya's Bluecontrol

  1. #51
    Master OptiBoarder
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    3,137
    Quote Originally Posted by Joe Zewe View Post
    It would be helpful if the manufacturers of these lenses offered a graph that shows the transmission percentages from 380nm through 500nm. When numbers are thrown around like "blocks 25% of blue light", without seeing either the raw transmission data or a plotting of the data, it is very difficult to assess the effectiveness of the lenses. In fact, transmission data above 500nm is also helpful as some of these lenses (especially tinted lenses) impact transmission above the blue light sprectrum.
    Absolutely!

  2. #52
    Master OptiBoarder
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    3,137
    Great info Mike

    Quote Originally Posted by MikeAurelius View Post
    I have to disagree. This same "issue" was brought up during the development of laser protective eyewear. There was a fear that the curve of the inside of lens would act as a reflector into the eye of an off-axis "behind and to the side" laser beam exposure. Multiple beam traces were done and not one single ray ever impinged on the eye.

    If the UV/Blue light is absorbed/reflected by the lens to any major extent, there is not enough left to "reflect" back into the eye. The very theory is nonsense. If there's nothing passing through the lens, what is it going to reflect off of? Is the eye all of a sudden a mirror?

    You might be able to sell this snake oil to a consumer, but it won't fly with professional opticians who understand filters and optics.

  3. #53
    Master OptiBoarder
    Join Date
    Jun 2008
    Location
    Seattle WA
    Occupation
    Optical Wholesale Lab (other positions)
    Posts
    3,137
    Quote Originally Posted by lensgrinder View Post
    ... Since blue light is about 33 times worse outdoors than it is indoors it should be of concern for outdoors just as it is indoors.
    A grey lens will transmit roughly 10% of the blue light and a brown lens roughly transmits <8%.
    One of the ironies of all this marketing hype is that potentially if you are using tablet, and not going outside, it would reduce your SWB exposure over all.

    Sunwear is the most important product to reducing SWB.

  4. #54
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    I'd sure like to see the data where the following was done and the methodology. The only way that the statement below could be true is if they had used full wrap protective frames as are in common use today in laser work. With ordinary spectacles, there is no way laser rays would NOT get into the eye, and it wouldn't be "through the lens", for sure.

    I have to disagree. This same "issue" was brought up during the development of laser protective eyewear. There was a fear that the curve of the inside of lens would act as a reflector into the eye of an off-axis "behind and to the side" laser beam exposure. Multiple beam traces were done and not one single ray ever impinged on the eye.

    If the UV/Blue light is absorbed/reflected by the lens to any major extent, there is not enough left to "reflect" back into the eye. The very theory is nonsense. If there's nothing passing through the lens, what is it going to reflect off of? Is the eye all of a sudden a mirror?

    You might be able to sell this snake oil to a consumer, but it won't fly with professional opticians who understand filters and optics.



  5. #55
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    Department of Defense.

    Aberdeen Test Center (US Army)

    Further testing was done at Los Alamos Nat'l Laboratory, Fort Hood, and Fort Hunter Ligget. Some of the test data and procedure is still classified, but the open source I've seen and know about was all done with Nd:YAG 1064 nm lasers, which is what most of the target acquisition lasers are. They run fairly high wattage due to the requirements for targeting, so a stray flash is very dangerous.

    My company was involved with the laser eyewear programs for both the Army and the Navy in the late 1980's through the 1990's. We manufactured lens blanks from Schott KG-3 and KG-5 for the optical laboratory in Yorktown NWS, and Fitzsimmons Army Medical in Denver. My company also manufactured completed laser safety spectacles for the AH-64 Apache and A-10 Warthog programs.

    All testing was done with 80th percentile head size/shape models to simulate normal wearing positions. Head models were fitted with laser receptors in place of (simulated) eyes. Lasers were arm-mounted and ray tracing was done from 180 degrees side exposure to approximately 250 degrees back and side exposure. A variety of vertical heights was used in conjunction with horizontal displacement. Helmets were not used, as these tests were to simulate hazardous exposure in a laboratory or test facility.

  6. #56
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    Quote Originally Posted by MikeAurelius View Post
    Department of Defense.

    Aberdeen Test Center (US Army)

    Further testing was done at Los Alamos Nat'l Laboratory, Fort Hood, and Fort Hunter Ligget. Some of the test data and procedure is still classified, but the open source I've seen and know about was all done with Nd:YAG 1064 nm lasers, which is what most of the target acquisition lasers are. They run fairly high wattage due to the requirements for targeting, so a stray flash is very dangerous.

    My company was involved with the laser eyewear programs for both the Army and the Navy in the late 1980's through the 1990's. We manufactured lens blanks from Schott KG-3 and KG-5 for the optical laboratory in Yorktown NWS, and Fitzsimmons Army Medical in Denver. My company also manufactured completed laser safety spectacles for the AH-64 Apache and A-10 Warthog programs.

    All testing was done with 80th percentile head size/shape models to simulate normal wearing positions. Head models were fitted with laser receptors in place of (simulated) eyes. Lasers were arm-mounted and ray tracing was done from 180 degrees side exposure to approximately 250 degrees back and side exposure. A variety of vertical heights was used in conjunction with horizontal displacement. Helmets were not used, as these tests were to simulate hazardous exposure in a laboratory or test facility.

    And they were all tested with wrap around, fully protective frames, right? Certainly not ordinary dress frames, right?

  7. #57
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    Nope. Randolph Engineering Aviators.

    http://shop.randolphusa.com/aviator-p5044.aspx

    6 base uncoated KG-3/KG-5 filter glass lenses.

  8. #58
    Master OptiBoarder opty4062's Avatar
    Join Date
    Mar 2008
    Location
    GA
    Occupation
    Dispensing Optician
    Posts
    416
    I wear prevencia with transistions 7. I have never noticed any blue reflections, not one iota, inside, outside, upside down, I do not see them Sam I am.

  9. #59
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    Quote Originally Posted by MikeAurelius View Post
    Nope. Randolph Engineering Aviators.

    http://shop.randolphusa.com/aviator-p5044.aspx

    6 base uncoated KG-3/KG-5 filter glass lenses.
    A yes the old Air Force pilot style. Fit many of them when I was in the USAF, before lasers were used or encountered in the cockpit for sure.

    Because they would offer precious little protection from lasers bouncing off the various items in the cockpit.

    And you guys can't see how a laser beam could hit the eye and/or the back surfaces of those lenses while wearing that frame?

    Don't try using those in an operating room where laser beams are bouncing off the walls. Use the side protected ones they always have on hand, or you could get burned.

  10. #60
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    Quote Originally Posted by opty4062 View Post
    I wear prevencia with transistions 7. I have never noticed any blue reflections, not one iota, inside, outside, upside down, I do not see them Sam I am.
    It's either a full wrap frame or you have a very large bushy hair style, or you wear a big sombrero, or you only wear them in the dark. I can think of one other reason. But I try to avoid going ad hominem.

    OK there's always the possibility they forgot to put those blue mirrors on there...

  11. #61
    OptiBoard Apprentice
    Join Date
    Dec 2011
    Location
    Wichita, Kansas, United States
    Occupation
    Optical Laboratory Technician
    Posts
    27
    Blu-Tech, second pair, for computer and digital devices.

  12. #62
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    Quote Originally Posted by Dr. Bill Stacy View Post
    A yes the old Air Force pilot style. Fit many of them when I was in the USAF, before lasers were used or encountered in the cockpit for sure.

    Because they would offer precious little protection from lasers bouncing off the various items in the cockpit.

    And you guys can't see how a laser beam could hit the eye and/or the back surfaces of those lenses while wearing that frame?

    Don't try using those in an operating room where laser beams are bouncing off the walls. Use the side protected ones they always have on hand, or you could get burned.
    And now you are an expert on laser eyewear???

    Look, bud, give it a rest. You've said your bit, I'm not buying it, and all you are doing now is embarrassing yourself.

  13. #63
    Master OptiBoarder opty4062's Avatar
    Join Date
    Mar 2008
    Location
    GA
    Occupation
    Dispensing Optician
    Posts
    416
    "It's either a full wrap frame or you have a very large bushy hair style, or you wear a big sombrero, or you only wear them in the dark. I can think of one other reason. But I try to avoid going ad hominem.

    OK there's always the possibility they forgot to put those blue mirrors on there..."


    Click image for larger version. 

Name:	012.jpg 
Views:	79 
Size:	25.3 KB 
ID:	12160 None of the above. Just sharing my personal experience, sorry it conflicts with yours.

  14. #64
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    Quote Originally Posted by opty4062 View Post
    "It's either a full wrap frame or you have a very large bushy hair style, or you wear a big sombrero, or you only wear them in the dark. I can think of one other reason. But I try to avoid going ad hominem.

    OK there's always the possibility they forgot to put those blue mirrors on there..."


    Click image for larger version. 

Name:	012.jpg 
Views:	79 
Size:	25.3 KB 
ID:	12160 None of the above. Just sharing my personal experience, sorry it conflicts with yours.
    If this is a pic of you wearing your prevencia lenses, I can see why you are not getting any reflections off the back surfaces. Your hair do is blocking pretty much all backside radiation. If you were to pull the hair back, tight to your head, face away from the sun, and rotate your head so that the sunlight can reach the back surface of one lens or the other, you will see a bright blue reflection. But don't stare at that reflection for long, it's loaded with UV as my video clearly shows. If you don't get a blue reflection off the back side, they are not Prevencia coated.

  15. #65
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    Quote Originally Posted by MikeAurelius View Post
    And now you are an expert on laser eyewear???

    Look, bud, give it a rest. You've said your bit, I'm not buying it, and all you are doing now is embarrassing yourself.
    Actually I AM an expert on LASER eyewear. I know that one of the major requirements of LASER protective eyewear is that it protect the eyes from stray LASER beams from all angles, including front, back, side, all 360 degrees. This is why all decent LASER protective eyewear have full wrap frames and/or side shields.

    But it doesn't take and expert to see that that old pilot style frame you showed doesn't provide any side or back protection at all. Even a layman could see and appreciate that.

    And no, I'll not "give it a rest" as I consider eye protection from LASER and UV to be a very important subject, one that I'll be actively engaged in for some time.

  16. #66
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    So, mr. snake oil salesman, exactly what are your qualifications to be an "expert" on laser eye protection? Have you been certified by the LIA? Are you up to date on all your CE's? Do you have the most current copies of the ANSI Standards for laser safety in your office?

    Because here's the thing, mr. snake oil salesman: lasers penetrate into filter substrates and are absorbed, they do not reflect, which, if you truly were an "expert" on "laser eyewear", you'd know that. You'd also know that
    "they would offer precious little protection from lasers bouncing off the various items in the cockpit.
    isn't even possible because "various items in the cockpit" don't have reflective surfaces, they have matte finish surfaces to dispurse and diffuse any possible beam impingement.

    If you are an EXPERT, you would know these things.

    As an aside, what is the registration number for your "noviolens" that you claim has a patent pending. As soon as you make the claim of "patent pending" on any public document, you are required to make the number available so that others can look to see that 1) it is an actual patent pending and 2) it does not violate someone else's existing patent.

  17. #67
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    Mr. Laser Protection Expert, what is the required protection level for a Class IV 100 Watt CO2 laser with a collimated 5 mm beam at 10.6 um? You should be able to answer that one real fast, it's an easy low and slow ball.

  18. #68
    Master OptiBoarder opty4062's Avatar
    Join Date
    Mar 2008
    Location
    GA
    Occupation
    Dispensing Optician
    Posts
    416
    Quote Originally Posted by Dr. Bill Stacy View Post
    If this is a pic of you wearing your prevencia lenses, I can see why you are not getting any reflections off the back surfaces. Your hair do is blocking pretty much all backside radiation. If you were to pull the hair back, tight to your head, face away from the sun, and rotate your head so that the sunlight can reach the back surface of one lens or the other, you will see a bright blue reflection. But don't stare at that reflection for long, it's loaded with UV as my video clearly shows. If you don't get a blue reflection off the back side, they are not Prevencia coated.
    Sure and if I close one eye and stand on one foot in traffic on a Saturday after 4pm in July I might get hit by a car. Dude, my simple point is, average user, average wear NORMAL circumstances equals NO blue reflections, in my personal experience. Your horse is dead sir, have some compassion.

  19. #69
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    I'm not sure why you take such offence at my attempts to alert the public about a potential hazard of UV radiation that is presented by makers of "blue protective" spectacle lens coatings. That said, I'm off to work in a few minutes and will do the best I can to take up your challenges above in the short time I have.

    My credentials are that I'm a graduate of U.C. Berkeley (class of '67, B.S., M.Opt.) where I first studied the physics of LASERs which at the time were only theoretical, since the first one was patented 3 years after I graduated. But the physics dept. at UC is where much of the early work was being done, and I took several classes in that very physics dept. We optometry students were shown that one of the valuable results of that work would be in eye surgery.

    I am not LIA certified, because I'm not directly engaged in LASER work, only routine eye care as a general optometrist and have no need for such an industrial certification. I know of no practicing optometrists who do, although no doubt at least one or two in the country do.

    Shortly after my graduation, I was elected to fellowship in the American Academy of Optometry.

    After that, I served 2 years as an optometrist in the USAF Biomedical Science Corps. and became familiar with the visual needs and demands of military aviation.

    After returning to CA I was appointed to 2 terms on the California Board of Optometry by the Governor. During my second term, I developed the first computerize examination for licensure for optometrists in California, and I think in the world. After my 2nd term I worked for the board as a consultant for disciplinary actions and examinations for licensure.

    Since then, I've been in private practice and am involved in fitting safety eyewear for several governmental agencies.

    Yes my CE is up to date, you can check with the Board in Sacramento, my CA license is # 5233 T.

    And yes, I have a copy of the latest ANSI standards in my office. What was it, about $200? I can prove it is not a pirated copy with my receipt of the purchase of about 4 months ago.

    Regarding your comment that

    "lasers penetrate into filter substrates and are absorbed, they do not reflect, which, if you truly were an "expert" on "laser eyewear"
    you'd know that."

    I know that your statement is completely wrong. I think most people with any scientific knowledge in this field know that LASERs reflect off any solid material. Sure, they can penetrate a substance, but no material I can think of is COMPLETELY transparent to LASER radiation.
    Yes, part of the radiation penetrating a substance can be absorbed by that substance, even causing damage to it (such as human tissue), and some can pass through (such as in an optical lens) but some is always reflected off according to all the laws of physics and math.

    As for your comment that

    "You'd also know that ... isn't even possible because "various items in the cockpit" don't have reflective surfaces, they have matte finish surfaces to dispurse and diffuse any possible beam impingement."

    another impossibly wrong statement. Just take a handheld laser pointer and shine it at any matte surface of your choosing. Just don't look at the reflection that comes off it.

    As for Noviolens, I was cautioned not to post anything that might be of a personal financial interest to me here, but you asked, so here it is:

    Application # 62/179,975 filed on 05/25/2015, USPTO confirmation # 7423 mailed to me on 06/12/2015.

    I'd be happy to fax a copy of that to anyone, including you.

  20. #70
    O.D. Almost Retired
    Join Date
    Dec 2009
    Location
    California
    Occupation
    Optometrist
    Posts
    998
    I'm off to work, but will tackle your next post(s) when I get a chance.

  21. #71
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    Quote Originally Posted by Dr. Bill Stacy View Post
    Application # 62/179,975 filed on 05/25/2015, USPTO confirmation # 7423 mailed to me on 06/12/2015.


    No such number in the USPTO search, which contains all confirmed filed applications through 8/4/2015.

  22. #72
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    All right, you've proven you're NOT an expert in Laser Safety Eyewear .

    Now as for the rest...

    I know that your statement is completely wrong. I think most people with any scientific knowledge in this field know that LASERs reflect off any solid material. Sure, they can penetrate a substance, but no material I can think of is COMPLETELY transparent to LASER radiation.
    Yes, part of the radiation penetrating a substance can be absorbed by that substance, even causing damage to it (such as human tissue), and some can pass through (such as in an optical lens) but some is always reflected off according to all the laws of physics and math.
    You have no idea how absorbers work, do you? Laser light does not reflect off an absorber, it enters the material, and the light is absorbed. The filter absorbers are specifically made to allow very small 10 to the minus 5th or less photon energy to pass through the material. Not reflected, absorbed. Again, if you were any kind of "expert" you would know this.

    I'll futher codify that IR absorbers will take on part of the energy they are being exposed to. The lens surface will bubble, pit, the lens will even crack, and if the beam is strong enough, it will eventually burn through (eventually can be .5 seconds or 5 minutes depending on a whole bunch of factors).

    Is there "some" reflection, yes, perhaps 10 to the minus 5th, and that meager amount will certainly be absorbed by another laser filter.
    Next:

    another impossibly wrong statement. Just take a handheld laser pointer and shine it at any matte surface of your choosing. Just don't look at the reflection that comes off it.
    Matte surfaces do not reflect. They absorb. What you are seeing is the impact point of the laser beam, not a reflection. Once again, **IF** you knew anything about lasers, you would know this.

    A basic primer on absorption (again, something that even as an OD you should know):

    Visible Light Absorption

    Atoms and molecules contain electrons. It is often useful to think of these electrons as being attached to the atoms by springs. The electrons and their attached springs have a tendency to vibrate at specific frequencies. Similar to a tuning fork or even a musical instrument, the electrons of atoms have a natural frequency at which they tend to vibrate. When a light wave with that same natural frequency impinges upon an atom, then the electrons of that atom will be set into vibrational motion. (This is merely another example of the resonance principle introduced in Unit 11 of The Physics Classroom Tutorial.) If a light wave of a given frequency strikes a material with electrons having the same vibrational frequencies, then those electrons will absorb the energy of the light wave and transform it into vibrational motion. During its vibration, the electrons interact with neighboring atoms in such a manner as to convert its vibrational energy into thermal energy. Subsequently, the light wave with that given frequency is absorbed by the object, never again to be released in the form of light. So the selective absorption of light by a particular material occurs because the selected frequency of the light wave matches the frequency at which electrons in the atoms of that material vibrate. Since different atoms and molecules have different natural frequencies of vibration, they will selectively absorb different frequencies of visible light.

    (emphasis mine)

    Here's the link for the above material: http://www.physicsclassroom.com/clas...d-Transmission

    Here's some more information about materials that are transparent to laser wavelengths:

    In several industries, an increasing need exists to cut, drill and mark glass, sapphire and diamond – materials that are difficult to machine using traditional mechanical methods due to their brittleness and hardness. Their transparency at visible and near-infrared wavelengths has also made them a challenge to process using lasers. Now, industrial solid-state lasers with pulse widths in the subnanosecond domain can perform a variety of operations on these materials.

    http://www.photonics.com/Article.aspx?AID=56800

    The Air Force uses FLIR target designators on their fighter bombers. The unit is encased in a hemisphere of fused artifical sapphire. And at 5 mm (approximately) thick is totally transparent to the Nd:YAG 1064 nm lasers the military uses for target acquisition.

  23. #73
    One eye sees, the other feels OptiBoard Silver Supporter
    Join Date
    Jul 2002
    Location
    Wauwatosa Wi
    Occupation
    Dispensing Optician
    Posts
    5,458
    I haven't seen the ANSI Z136.8 recommendations, but I wouldn't risk wearing laser safety eyewear that doesn't provide an adequate amount of peripheral protection.

    Old, but relevant.

    http://www.mdsr.ecri.org/summary/det...px?doc_id=8201
    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.



  24. #74
    Banned
    Join Date
    Jul 2010
    Location
    St. Cloud, Minnesota
    Occupation
    Ophthalmic Technician
    Posts
    3,089
    Quote Originally Posted by Robert Martellaro View Post
    I haven't seen the ANSI Z136.8 recommendations, but I wouldn't risk wearing laser safety eyewear that doesn't provide an adequate amount of peripheral protection.

    Old, but relevant.

    http://www.mdsr.ecri.org/summary/det...px?doc_id=8201
    You are absolutely correct, Robert, peripheral protection is a must, and in many cases, a requirement. However, it isn't for "reflected exposure from the back surface of the lens", it is for off-axis direct impingement on the eye itself, where the LSE doesn't cover correctly or properly.

    The test I described above was performed to put to rest questions about reflected laser energy from the backside of the LSE into the eye. Off-axis impingement was already a known quantity and the reason why peripheral protection was written into the standard.

  25. #75
    Manuf. Lens Surface Treatments
    Join Date
    Aug 2002
    Location
    in Naples FL for the Winter months
    Occupation
    Other Optical Manufacturer or Vendor
    Posts
    23,240

    Redhot Jumper Here are Hoyas Claims

    Here are Hoyas Claims :

    BlueControl Benefits



    HOYA BlueControl lenses help:



    • Neutralise blue light, preventing eye strain and fatigue
    • Reduce glare for a more comfortable and relaxed vision
    • Enhance contrast perception offering a more natural colour experience
    • Protect your lenses against water, dirt, grease and dust, keeping them clean for longer




    see at : ==============>

    http://www.bluecontrol.eu/en/benefits

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Hoya and Essilor
    By buckeyefan in forum Progressive Lens Discussion Forum
    Replies: 12
    Last Post: 07-29-2014, 11:04 AM
  2. ESSILOR to HOYA
    By manoj_verma in forum General Optics and Eyecare Discussion Forum
    Replies: 4
    Last Post: 09-24-2012, 03:55 PM
  3. Zeiss, Shamir, essilor & Hoya
    By viluzb in forum Progressive Lens Discussion Forum
    Replies: 4
    Last Post: 11-08-2011, 02:46 PM
  4. Help! : Essilor vs. Hoya (Company Comparison)
    By jczelust in forum General Optics and Eyecare Discussion Forum
    Replies: 38
    Last Post: 03-30-2011, 09:52 PM
  5. Essilor Stylis or Hoya Eynoa
    By joerg in forum General Optics and Eyecare Discussion Forum
    Replies: 1
    Last Post: 02-08-2006, 06:49 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •