Everything to Know About Blue Light and Crizal Prevencia

This post is sponsored by Essilor of America, Inc.
14 min read

Crizal Prevencia is a lens from Essilor that blocks blue light from reaching the patient's eyes. Learn more about the science behind Crizal Prevencia with this handy guide.

Everything to Know About Blue Light and Crizal Prevencia
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.
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 filters 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 filtering out the narrow band of blue light from 415-455 nanometers (nm) which has been studied and understood to impact circadian rhythm and potentially impact the retina.
The Crizal Prevencia lens does not filter out 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 filter out 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

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⁾

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⁾

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.
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.

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
  1. Computer software engineers
  1. Web designers
  1. Call center staff
  1. Accountants
  1. Sales reps
  1. Patients who have undergone cataract surgery - without their old, yellow ocular lens, their retinas are especially susceptible to blue light
  1. Those spending time on the computer for greater than 4 hours / day
  1. Those having trouble with nighttime glare
  1. College students
  1. 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!
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
(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
Matt Geller, OD
About Matt Geller, OD

Matt Geller, OD is the co-founder and CEO of Eyes On Eyecare—the #1 provider of clinical and career education for the next generation of optometrists and ophthalmologists through our all-in-one digital content platform.

Matt Geller, OD
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