Everything to Know About Blue Light and Crizal Prevencia

This is a sponsored post by Essilor, a supporter of NewGradOptometry & new graduate optometrists 😎 !

If you’re a new graduate and you are prescribing the bare minimum for every patient, I can guarantee you one of three things will happen.

  1. You will get fired
  2. You will get a long sit down talk with your boss about how to prescribe
  3. The practice will close its doors due to bankruptcy

The reason one of these things will happen is because a practice cannot keep its doors open with the bare minimum in lens prescribing.

I define bare minimum as some combination of – single vision or bifocal, plastic, no progressive, no AR, no Transitions® , Crizal® Prevencia™, no digital, with basic crumby frames.

Now the first thing I want to make clear is that the act of prescribing the bare minimum versus a high-end pair of glasses is not “up-selling” or wasting the patient’s money. Prescribing a pair of lenses with the latest technology is something every OD should offer their patient. When patients come into my exam room we discuss “Maximum Visual Performance” (MVP), and you cannot achieve that level with the bare minimum pair of lenses.

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A patient pays under $2.00/day over 1 year, for a pair of glasses with the latest technology. I have no problem prescribing a $600 pair of lenses when I know the benefit it will bring to the patient’s life. It is not up-selling; it’s being a doctor who wants the best for their patient. It might not be for everyone, but I am not going to assume and judge a patient, I will always bring up the topic.

With that being said, let me give you some help when it comes to prescribing Crizal® Prevencia™, a No-Glare lens from Essilor that is absolutely epic. By following this guide, you will undoubtedly increase the quality of the lenses you are prescribing and hence your revenue per pair of glasses.

About Crizal® Prevencia™

Crizal Prevencia is a No-Glare lens that blocks out specific wavelengths of  blue light from reaching the patient’s ocular tissue. It is basically an Anti-Reflective (AR) lens, similar to standard Crizal® No-Glare treatment, except it is specific to blocking the narrow band of blue light from 415-455 nanometers (nm) which is specifically the “retinal damaging” light.crizal-prevencia

The Crizal Prevencia lens does not block the 480nm spectrum and therefore will not affect suppression of melatonin, the chemical that regulates the sleep/wake cycle. This is a particular advantage for patients that would like to keep their sleep/wake cycle untouched. It is something I tell patients about and is a great way to convey the value of this lens.

  • Crizal Prevencia is proven to deflect harmful blue-violet light by 20%*(1)
  • Crizal Prevencia has an Eye-Sun Protection Factor (E-SPF®) of 25, which means 25x times more UV protection for your eyes compared to wearing no lens at all*⁽²⁾

This lens is completely clear, unlike other  competitive yellow blue-blocking lenses. This is a great choice for those who do not want a “socially awkward” yellow lens. This lens does have a purple hue on the front side, that can been seen under certain conditions and it indicates that the lens is actively blocking harmful blue-violet light!


Understanding the Concept of Blue Light

You have heard the science behind this, there is no doubt about it, but let’s do a quick crash course.

  • The colors of the visible spectrum closest to the blue-violet side are the highest energy, while the colors closer to the red end of the spectrum have the weakest energy.
  • The average proportion of blue light that’s found in sunlight during the day is between 25% to 30%.

Visible light is electromagnetic radiation, just like other radiation (ie – radiation from a nuclear spill or from your cell phone). The closer you get to the source, the stronger the radiation. That is why I always tell patients to keep a generous working distance to decrease their chances of blue light exposure.

In physics, an inverse-square law  states that electromagnetic radiation (visible light) is inversely proportional to the square of the distance from the source of that physical quantity.

In equation form:

Also remember – blue / violet light is DIRECTLY adjacent to UVA in the spectrum. UVA is from 315 – 400nm and violet light is 380 – 450nm. To over simplify the argument, we can basically consider UVA to be the same as violet colored light.

Studies over the past two decades, however, show that UVA damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers occur. (Basal and squamous cells are types of keratinocytes.) UVA contributes to and may even initiate the development of skin cancers. – Skincancer.org

visible spectrum blue light lenses

Types of Visible Light

  • Daylight – Provides a broad spectrum of all colors. We wear sunglasses in order to block out UV and thankfully this also blocks blue light.
  • Incandescent – Warm colored light with a low proportion of blue light. These are your 40 watt and 60 watt bulbs – the government is currently pulling incandescent bulbs away from retailers. That leaves our patients only halogen, LED and Compact Fluorescent bulbs to choose from.
  • Fluorescent – These bulbs are shifted toward the blue end of the spectrum and contain about 25% blue light. These are those long tube-looking bulbs that flicker. You probably have them in the room you are sitting in right now; that’s right look up to the ceiling! Clinical research has also show that they may have a negative effect on brain function.
  • Halogen – These have a low amount of blue light. Halogen is a 43 watt bulb and is often used in homes to provide warm color light. I like these the most for my exam room and at home.
  • Cool White LED – The worst of all options for blue light, cool white LED’s have around 35% of blue light! Cool white LEDs are used in you computer screen, tablet, most smart phones, and TV. These also tend to be the light sources closest to our eyes (remember the inverse-square law). With the advent of cool white LED, blue light is more prevalent than it has ever been! Keep in mind, an LED light can exhibit any color of the visible spectrum. Not all LED lights are bad for ocular tissue, just the bright white and blue/violet colored LED lights.⁽⁷⁾

visible light new grad optometry crizal prevencia

If you think Crizal Prevencia is a good lens, then you should read this article about what’s new with Transitions lenses.

What Blue Light Does to Eyes

Once again, you know how this all works. Here is a crash course.

Here are some key studies to remember

  • The theory is that blue light contributes to retinal disease, lenticular disease and ocular surface disease.
  • Essilor and the Paris Vision Institute did a study that exposed procrine retinal pigment epithelium (RPE) cells* to blue-violet Light (415nm – 455nm), reproducing the physiological exposure to sunlight of the 40-year-old eye. The study found that the retinal cell death rate decreased by 25% when there was a 20% cut out of blue-violet light.⁽¹⁾
  • A study in 2006 called Age-related maculopathy and the impact of blue light hazard” showed us that blue light is considered 50 to 80 times more efficient in manifesting retinal photoreceptor death than green light. ⁽³⁾

Facts to Remember

  • The NEI tells us that in 2012 there were approximately 24 million cases of cataracts in people aged 40+ in the USA, a 19% increase from 2000. By 2050 the NEI assumes that cataracts prevalence will be at 50 million!⁽⁴⁾⁽⁵⁾
  • The NEI tells us that in 2012 there were approximately 2 million cases of macular degeneration in people aged 50+ in the USA, a 25% increase from the year 2000. By 2050 the NEI assumes that macular degeneration prevalence will reach 5 million and that means 6.3 million people will likely become legally blind.⁽⁵⁾⁽⁶⁾

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Prescribing Crizal Prevencia

The reason I wrote this article is to give you the confidence to prescribe Crizal Prevencia No-Glare lenses. I feel that confidence comes from a combination of knowledge and experience. I gave you some knowledge, now I will give you my experience.

Step 1: Understand Crizal Prevencia lenses and blue light

You need to start by understanding more about blue light and about Crizal Prevencia. First off, reading this article was a step in the right direction, but here are my top 2 links for learning more about these two factors.

Essilor and ECP University

ECP Univeristy Lens Training Program – Learn more about Crizal Prevencia No-Glare lenses through the Essilor ECP University Online. This is a really slick online training dashboard that is available to you and your entire staff 24×7.


NGO-Logo-2xGary Morgan OD on Blue Light – CovalentCareers Podcast – 
Understand the basics of Blue Light in this podcast from Dr. Gary Morgan.


Step 2: Get your own pair of Crizal Prevencia Lenses

The easiest way to prescribe a pair of Crizal Prevencia lenses is by showing your patients that you wear them. I tell my patients about my time spent in front of the computer and how important I feel it is to protect your eyes.

If you stand behind the product, so will they.

Step 3: Identify the right patient

While everyone can benefit from Crizal Prevencia, you really should be smart about how you pick your battles. Trying to make the pitch to everyone is wrong. You will become discouraged and seem like a salesman, not a doctor.

Here are the people who can benefit most from Crizal Prevencia.

  1. Children who spend time on electronic devices such as iPads / iPhones
  2. Computer software engineers
  3. Web designers
  4. Call center staff
  5. Accountants
  6. Sales reps
  7. Patients who have undergone cataract surgery – without their old, yellow ocular lens, their retinas are especially susceptible to blue light
  8. Those spending time on the computer for greater than 4 hours / day
  9. Those having trouble with nighttime glare
  10. College students
  11. Patients that have a family history in, or are predisposed to retinal diseases such as age-related macular degeneration

Step 4: Put blue light & Crizal Prevencia in layman’s terms for patients

Here is the pitch I make.

You put suntan lotion on your skin when you go out in the sun for the day, right? Well if you believe that suntan lotion protects your skin from harmful UV, you should be putting on blue light-blocking eyeglass lenses when at the computer! Blue light is the wavelength that is adjacent to UVA, they are literally separated by a few nanometers. The only difference is that UV is invisible and blue light is visible. So think about putting on Crizal Prevencia lenses, “sunscreen for your eyes”, next time you are at the computer.

Getting Crizal Prevencia in Your Practice

This part is perhaps the easiest.

All you need to do is call your Essilor sales rep. They will come in and provide you marketing materials, education, pricing and lab information. In some instances you might be able to obtain a voucher so that you can try the lenses yourself.

I am not going to attempt to do that right now, but I can tell you that almost all labs can do the product for you, that the price margins on Crizal Prevencia are great and that patients will appreciate it. You just need to talk first with your brand sales consultant.

Summary – How to Prescribe Crizal Prevencia with Confidence

We have now come full circle.

My original point was that if you don’t prescribe the best possible ophthalmic lens for visual performance, you will lose patients to an optometrist or ophthalmologist who will. In addition, you probably won’t stay in business very long because it will be impossible to cover your overhead expenses.

I stand by that point.

My patients enjoy Crizal Prevencia lenses and I do too. I am wearing a pair right now as I write this article! I have talked to many doctors, ophthalmologists and optometrists who are certain that without blue light protection, ocular disease will increase. So for about $1.00/day for one year, I can give my patients that protection!

Read The Prevencia Website

What do you think? Shoot some comments below.

READ NEXT: If you think Crizal Prevencia is a good lens, then you should read this article about what’s new with Transitions lenses.


(1) 25% less light-induced retinal cell death rate versus a naked eye, with a 20% cut of blue-violet light. In vitro experiments conducted by Essilor and Paris Vision Institute. Retinal pigment epithelium cells were exposed to blue-violet light, reproducing the physiological exposure to sunlight of the 40-year-old eye.

(2) E-SPF of 25 means the wearer is 25 times more protected than without any lens. E-SPF of 25 when Crizal is made with any lens material other than 1.5 clear plastic.

(3) Age-related maculopathy and the impact of blue light hazard. Acta Ophthalmol Scand. 2006 Feb;84(1):4-15. Algvere PV1, Marshall J, Seregard S. http://www.ncbi.nlm.nih.gov/pubmed/16445433

(4) Vision problems in the U.S –  http://www.preventblindness.net/site/DocServer/VPUS_report_web.pdf?docID=1322

(5) NEI – https://www.nei.nih.gov/eyedata/cataract.asp

(6) Singerman LJ, Miller DG. Pharmacological Treatments for AMD. Review of Ophthalmology. Oct. 2003.

(7) Full-Spectrum Fluorescent Lighting Effects on People: A Critical Review Jennifer A. Veitch, Ph.D. and Shelley L. McColl, National Research Council of Canada, Institute for Research in Construction, Ottawa, ON K1A 0R6

*This article is an advertorial for the company Essilor. We would like to let you know that NewGradOptometry, LLC has chosen to work only with companies who support new graduate eyecare professionals, the profession of optometry and who our team believes in. We will always remain true to that.

About Matt Geller

Matthew Geller
Dr. Matt Geller is a technology entrepreneur with a track record of developing successful online platforms to solve problems in the healthcare space. Matt is an optometrist in San Diego and is the founder of OptometryStudents.com, NewGradOptometry.com and the co-founder of CovalentCareers.com!


  1. Hey Matt..I got my pair of Crizal Prevencia lenses.. But I’m really annoyed by the intense violet reflection of any light behind me on the side of the lenses. Is there something wrong with my lenses ?

    Your feedback is much appreciated.

    Thank you.

    • Matthew Geller

      Hey Aman!

      Nope, there is nothing wrong with your lenses. The violet reflection that you see is the lens actively blocking the 415 – 455nm light from your environment. As with many glasses, sometimes you must modify your environment to avoid any reflections that come from behind you. Additionally, check with your optician regarding adjusting the “vertex distance” of your glasses. If the glasses are too far from your eyes, light can get back there and cause reflections. I hope you enjoy them. I am wearing mine as we speak!

      -Dr. G

  2. You asked for comments, so here goes.

    I went into get new eyeglasses a couple of days ago. The optician suggested

    Varliux Physio Enhanced Lenses
    1.67 High Index ASPHERIC
    Crizal Prevencia UV
    UV-400 Protection.

    The associated cost for just the lenses came to $688. The prices for the frames and the examinations were separate. I now think that $688 for just the lenses is very high. At the time of purchase, I rationalized the price with “Well, I don’t want to go cheap on my eyes”. After doing some research online, I’m all the more convinced that this price is extremely high. Other opticians (it appears) can provide the exact same materials and treatments for about 40% less.

    What do you think?

    • Matthew Geller

      Hey Ward!

      Thanks for the comment. Great choice in going with the “fully loaded” pair of glasses! You got some of the best materials that exist so congratulations on that.

      To be honest, you got a really good price. Of the 3 practices that I have worked for both, all 3 would have charged you more. The price for the Crizal Prevencia is VERY similar to the cost of your general high-end Anti-Reflective coating like Crizal Avance and with that being the case you would have spent nearly the same money if you went without the Prevencia.

      I would be very weary of the comment that it would have cost you 40% less, that simply can’t be possible. Sure, you could have received materials that “in theory” function the same but really lack the optics and quality that Varilux and Crizal have. Also, those materials are warrantied, typically for 2 years, so scratches and stuff like that can get you new lenses (at least at my practice).

      If you have other questions, comment below. $688 is a good price and I hope you like your new glasses… VERY smart choice going with Prevencia!

      -Dr. G

      • Sean kenney


        I recently went to order my lenses however when I asked about the Prevencia she did not know how to order them. She just selected the highest coating option. How can I be sure it is the prevencia?

        What can I ask to see to prove it would be what I want. Otherwise I would rather go to an office that provides them.

        also regarding the coatings do I need to add a UV coating? I thought the prevencia had all of them.

  3. Hey Matt,

    What about Hoya BlueControl?
    Same benefits, quality, protection, prices .. ?

    Thank you!

  4. This is the article I just ordered a Prevencia but reading the comments I wonder how I got it for so cheap! Just 700 Saudi Riyals (approx 190$) I ordered them at a very prominent opticals store. Anyway, I guess I’ll know if I’ve been duped with purple hue inspection.

    But this wasn’t the main reason to post this comment, instead I just wanted to thank you for writing about the lens so clearly, it’s better in explanation that the brand’s own website. Also, I firmly believe in the idea of MVP and I’ve always tried to get the best lens possible and the yard stick to measure the best lens was the price it was sold at and most of the times I was disappointed. But your article has given me enough details to be happy about and I shall update you next week when I receive my new pair.

    Many thanks,

    Mushtaq Hussain

  5. Hey Mushtaq, great comments regarding the “purple hue inspection” It can be easy to get duped as you say, one thing you should request is the authencity cards that accompany Crizal products – no cards is a good indicator that something might be odd.



  6. Hi my pairs arrived today, all seems to match with your description, however only one thing, the lens is mildly yellowee, put it on a white piece of paper and you can see the yellow of the lens, like old lens. It doesn’t come with authencity card either. Is the yellowee thing normal?

  7. Kim

    The yellowed or green tint is apparently normal as I was told today. I don’t like it as it actually changes the colour of things around me. I know it’s to make the eyes relax especially those who work on computers eye but this is not for me. I am getting the lenses recut and they will not have this green tint or at least not as much….I’m not a fan of the purple vibrant anti reflective coating! Not normal for glasses to give everything around a green tint!

    • Matthew Geller

      Hey Kim,

      Yea I totally understand what you mean. Clinically, the tint won’t alter your true color perception, but it may be subjectively noticeable. I prescribed these often for people who use them as every day glasses, and most patients were really happy. For average and above computer users, this lens is really fantastic. It sounds like you gave it a shot, which was a smart thing to do. I encourage the lens for people who are curious about enhancing their comfort and vision.

  8. Ketan mahale

    Hello Matt,
    Thank you for clearing all about the crizal prevencia.
    But my doubt is something different. I wish you to help me in this.
    I have found few lenses of MR8 material with laser cut technology, which don’t even have Blue coating on it, the interesting factor is that the lenses cut 100% rays. if we put a LASER light on the glass, the rays get reflected back and does not transmit through the lenses. the nanometer of LASER light was between approx. 400nm – 500nm.
    Now, Blue light has a wavelength of between approximately 380nm and 500nm; making it one of the shortest, highest-energy wavelengths.
    So, which lenses are better, Laser cut or Blue Coating.
    I have checked few Blue coating lenses wherein after transmitting the LASER light, the light transmits through the lens but slightly get dispersed.
    and how will the essilor Crizal prevencia lens does not block the 480nm spectrum, what is the technology behind it.
    Hopes for your reply.

    Ketan M

    • Matthew Geller

      Hey Ketan,

      Thanks for reaching out, happy to provide info on the lenses! It sounds like the MR8 lenses are great but slightly different.

      The main feature of Prevencia is how selective they are at blocking one particular wavelength range, which is ideal for a very specific type of patient situation. Many of my patients do not want to block a broad range of the visible spectrum, but only the specific 415 – 455nm range.

      It sounds like the MR8 cuts all visible light equally, which might be ideal for a patient who wants a broad spectrum decrease in visible light, but just because it “blocks all” does not necessarily mean it is “better.”

      Healthcare and especially eyecare is becoming more and more personalized, and choices are more accessible than ever. It seems like Prevencia is for a patient who wants to achieve the very specific function blocking out retinal damaging blue light from digital devices. The MR8 lens you describe is likely the ideal choice for a patient who might be photophobic (light sensitive) and isn’t specific to the blue light range.

      When thinking about the choice for you, start with your end goal. If blue light is your primary concern, Prevenica might be best for you!

  9. Ketan mahale

    Hello Matt,

    As per your suggestion I went for crizal prevencia glasses, and wearing since 10 days,
    My first question is that how will I identify crizal prevencia 1.56 index and crizal prevencia Airwear 1.59 index, As i am wearing Rimless frame and was suggested for Airwear. I do got authenticity card but its blank….no worries.. but how should one identify Airwear prevencia
    Second thing this glasses are slightly yellowish like old polycarbonate glasses, reading above chats though cleared on it.
    please help on how to identify Airwear one

  10. Mohammad mohsin

    Hi Matt,
    I have been using the Progressive varilux s 4D lens with preventia coating for the last one week and I should say that I am not happy with night time vision because of the glare I get through these lenses especially the glare of the red and green signal lights and headlights of of the cars.
    What can be done to decrease the glare?
    Which is better, a transition or preventia coating?
    Thank you

    • Antonio Chirumbolo

      Hey Mohammad,

      To a degree, nighttime glare is something everyone struggles with. Anti glare coatings on lenses are one of the only things that can be used to help reduce this issue. The Prevencia does have anti glare coating on it. I don’t believe Transitions will do much more than Prevencia in regards to helping with Glare issues particularly at night. Crizal Sapphire might be another product to look into, but Prevencia might be the best overall lens option which sounds like you already are utilizing.

  11. Mohammad mohsin

    Dear Antonio,
    Appreciate your quick reply.
    I am surprised that I don’t find any difference as far as the nighttime glare is concerned between my preventia coated lens and the standard dollar 75 lens I was using before this. Sometimes I feel that my old lens is somewhat better at night glare reduction.
    Is there any issue with the anti glare coating in my prevencia lenses?
    Another question is that I have been suffering from ciliary spasm which causes double vision after I read constantly for about 30 minutes. This problem has worsened after I started using my new progressive varilux 4D prevencia coated lenses. My eyes are tired only after 10 minutes of reading and it takes longer rest time for the vision to improve. Could you please help me with this.
    Thank you.

  12. Melwyn Fernandes

    Can anyone suggest as to which is a better option for lenses between Crizal Prevencia and Tokai Lutina?
    Also, what would be average cost for Crizal Prevencia, Crizal Prevencia with Transitions & Crizal Prevencia Transitions Xtractive?

    • Antonio Chirumbolo

      I personally have no experience with Tokai Lutina so I’m not sure I can comment. I do have a lot of Crizal Prevencia wearers in my practice and have gotten great feedback on the product. The average cost of those items does vary between offices and insurance companies so it is a difficult question to answer.

  13. PrinceVegeta

    Is Crizal prevencia better than forte uv? What are the differences? Because both have blue light protection and same uv protection index

  14. Rohit Sharma

    Hi Matt / Experts,
    Can you please help me understand the difference between Prevencia and Eyezen Lenses?

    • Antonio Chirumbolo

      Hi Rohit,

      There are a few differences between Prevencia and Eyezen lenses.
      Prevencia is an anti-glare coating that blocks against disruptive light and harmful blue light.

      Eyezen lenses block against harmful blue light with their Smart Blue Filter but also have an added power for computer and reading near the middle to bottom of the lens for those spending lots of time on computer.

      To get the most protection and best visual experience, sometimes people get Eyezen lenses and add Prevencia anti glare coating to it to get the best of both worlds.

  15. Antonio Chirumbolo

    Hi Rohit, so, your prescription can certainly be used with Eyezen lenses.
    The added power I speak of is in the middle to lower area of the lens. It is a computer power that will allow your eye muscles to relax when looking at computer screens or reading a book for example. You won’t necessarily notice this power, but your muscles will feel better.

    I think that Eyezen could be a great choice for you based off of what you describe. You could always get Eyezen with Prevencia since Prevencia is an anti glare treatment.

  16. Rohit Sharma

    Hi Antonio,
    I got my Eyezen today and I can feel the difference while reading on my phone.
    Thank you so much for your advice.
    I have another question though. I have read that there is no fog id on these lenses. Is there any way to verify if those are authentic?

  17. Rohit Sharma

    I can see below markings near the nose pad:

    1. Lambda sign
    2. A circle
    3. A sign for Eyezen 1 = a circle with 3 arcs on it.
    4. A circle on left and right side of left and right eye respectively.

    Do you know what these mean?

  18. Auldrich Delossantos

    Gooday sir/mam!

    Just want to ask about the fog i.d on my crizal prevencia lenses, just got it right now!
    There was a fog i.d on my lenses! It says CRIZAL!
    In other coments many says crizal prevencia has no fog i.d but mine has it. Im going crazy right now. I want crizal prevencia as it is!

    • Auldrich Delossantos

      And when i tried to focus it againts flashlight! Nothing happens! its so bright!
      Is it normal for my crizal prevencia? I am super sensitive into lights stressful at night because of the headlights and tailights!

      Anyone can i talk and send some picture to let you see if its original essilor lenses?

      Thank you!

    • Antonio Chirumbolo

      Hey Auldrich, you might have gotten the fog ID as an add on. That is just extra technology that should enhance your prevencia. The prevencia works great to block reflections. Where did you get the lenses? From your local doctor?

      • Auldrich Delossantos

        Oh thank God you answered!

        Im going crazy right now.

        Nothing happens into bright lights even a little bit! and has alot of scractches now.

        I am not satisfied in this kind of quality!!

        Whats wrong with this lens?? Is this fake? I tried to tell my optician about this problem,, but she said that its the original lens nothng to do about it.

        Pls help me ,, i feel like wastng my money!

        Based on my research about this lens is very good but when i wear it im disapointed!

        • Antonio Chirumbolo

          Hey Auldrich, I am fairly certain that these lenses come with a certificate of authenticity. I can’t imagine your optician would sell you a counterfeit product, but obviously, there’s no way I could know.

          It is possible that you might even benefit from a slight tint to your glasses or Transitions if your eyes are extremely sensitive to bright lights.

  19. BB Optician

    Hi Dr. Geller. I provide my patients with various blue light lens options. There is some confusion about how much blue light (or HEV blue light) is being filtered/reflected with AR lenses like this. First, Essilor states that Prevencia AR “protects” from 20% of HEV blue light. Essilor recently has said that all of their lenses will include Smart Blue Filter, so that means 30% HEV protection for the new, clear, non-transitions lenses, right? (example: Stock Polycarbonate Crizal Prevencia UV35)

    What part of the HEV blue light range do these lenses actually protect from in nanometers? 415 to 455nm (as stated in your post) is more like 50%. 30% seems to me to be way lower. Can you clarify this percentage versus EM range issue for me please? Thanks in advance!

  20. Oyee

    Hi, just got my eye glasses with Crizal Prevencia lenses two ago. How will i know if i have authentic lenses. I don’t see hologram of crizal for both lenses. The dealer did not give me any authenticity card nor crizal cloth. On my receipt showing Crizal Prevencia progressive, transition.
    Transition is working fine but im not sure if its progressive. How will i know it is progressive lenses?
    Thank you

    • Antonio Chirumbolo

      Hi there, typically, your glasses are usually dispensed with a crizal cloth and or card. Where did you happen to purchase your lenses? You will know if it is a progressive lens if you are able to see far, intermediate, and up close through the glasses.

  21. Angel

    How can i check if my essilor lenses has blue filter?

    • Antonio Chirumbolo

      Hi Angel, did you elect to have a crizal coating on your glasses? Do you have transitions lenses? Where did you purchase your glasses from? If you purchased them from your optometrist, he/she should be able to inform you.

      • Angel

        i dont have transition lenses. the customer rep told me that it has the smart blue filter which i cannot see it when i shine a light in the lenses. So I would like to know how to test if it really does have blue filter.

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