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Why the blue light laser pen doesn’t have all the answers

Harmful indoor blue light is an important topic, and many consumers are aware of the dangers it can pose, such as digital eye strain, which causes: 

  • Headaches
  • Tired or burning eyes
  • Slow focusing
  • Blurred vision at distance
  • Dry eyes
  • Neck, back or shoulder pain


Download this PDF for a condensed version you can refer to as needed. 


In our digitally-driven world, people have to face the screen to work, socialize, learn, and live daily — there’s no getting around it. Still, they shouldn’t have to simply live with the symptoms that come with this tech-enabled lifestyle. As an ECP, that is your top concern.


The good news is, most optical lens manufacturers today offer lenses and/or lens treatments that will filter blue light — so you can make sure your patients receive the solution that will improve their quality of life. 


The problem is, there is some confusion about which blue light filtering lenses to offer. And we’re here to help clear that up!


A closer look at indoor blue light lens solutions

Indoor blue light lens solutions — whether specialized substrate or lens treatment — are regularly offered to provide protection to those who work on digital devices for long periods of their workday. 


To help patients understand the blue light filtering properties behind the lenses or treatments, an ECP will cast a blue LED flashlight or blue laser through the product. The amount of blue light that does not pass through the product is a validation that the product is effective at filtering harmful indoor blue light.


This is where we experience a common misconception. 


Many treat the decrease of blue light passing through the lens as a validation that the lens is filtering the correct portion of the blue light protection. In reality, there is more information you need before making that assumption — and before offering a specific blue light solution.  



Establishing a blue light threshold

Each manufacturer designs their indoor blue light solution to filter a specific portion of the blue light spectrum. So, the first thing we need to understand is what portion of the electromagnetic spectrum comprises blue light — and more specifically, what portion of the blue light spectrum has been shown to cause damage or retinal insult:


  • Blue light is 380nm to 500nm
  • Blue light shown to cause retinal insult is 420nm to 460nm
  • Blue light below 420nm is associated with scatter and haze 
  • Blue light above 460nm is associated with circadian rhythm 


Next, we need to understand what range of light is being emitted from the flashlight or laser being cast through the product:


  • Many blue light LED flashlights are 395nm
  • Many blue light laser pens are 405nm


Important to note here: both types of demo lights emit light most associated with scatter and haze — not retinal insult. These lights also emit a limited band of blue, not the entire 120nm range of blue.


Now, as we look closer at each light in this context, we can find a ‘range’ that is emitted. 


  • Each manufacturer has a +/- range that should be accounted for.


What that means: the lights not only emit light in a range outside of what we are claiming to protect against, we also cannot guarantee that the light is emitting the actual light ray stated on the instrument. 


When a blue LED flashlight or laser pen is cast through a blue light solution product, what we are really demonstrating is how well that product filters light that causes scatter and haze. It’s not providing the full picture we need regarding retinal insult.



Next steps to providing the right blue light solution

If you are looking to provide protection against retinal insult, remember to ask how much light is filtered between 420nm and 460nm — the flashlight/laser demonstration will not provide this information. You must understand what each product will protect against and what your patient’s visual needs are. 


We understand that there is not a one-size-fits-all solution that will work for every situation. At HOYA, we have many options:




For more details on blue light please read our white paper “What We Know – And Don’t Know – About Blue Light.”

Want more information about our blue light filtering lens products? Contact your HOYA Territory Sales Manager for more information.

And if you found this content helpful, download this PDF for a condensed version you can refer to as needed.