Adding a Blue Light Coating to a Light-Reactive Lens? Here Are 3 Reasons Not To.

Everyone likes the idea of getting more. The concept of squeezing as much as possible into or out of anything appeals to the value seeker in us all. McDonald’s® figured this out decades ago when the concept of an ordinary value meal no longer satisfied the masses. “Supersize it” became an instinctive add-on to your order of a “number 3 with a Coke.” After all, a meal’s not a meal without 32 extra ounces of soda and enough fries to fill a Fiat, right?  

But other that an extra helping of calories and a massive sugar crash two hours later, what’ do you get out of adding and adding and adding?  Often, piling on more doesn’t yield much benefit, and can do more harm than good.
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Here’s the point where we connect a value meal to a light-reactive lens.  

On the surface, the idea of layering on an extra helping of blue light defense on a light-reactive lens sounds like a no-brainer. After all, a photochromic already offers outstanding blue light filtration. So, adding a blue-light coating must supersize the amount of defense, right? Well, not really.

In fact, adding a blue-filtering enhancement to a light-reactive lens only offers a minimal increase in defense. And just like ingesting a supersized meal, the consequences could far outweigh the perceived value.
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With that in mind, let’s take a look at three reasons not to put a blue light coating on a light-reactive lens:

1. It's Unnecessary

As previously stated, light-reactive lenses offer outstanding blue light filtration in both clear and dark states. Looking at the spectral transmittance graphs for SunSync Elite below, you can see it provides excellent defense across the blue light spectrum, with up to 98% filtration in the 400-430nm range where digital eye strain occurs. 

Since you can’t surpass 100%, adding a blue-light coating would only yield an extra 2% of reduction at best (SunSync Elite filters approximately 98% at 400nm, leaving only 2% to reach 100% filtration). Not really the cost-benefit result that one might be hoping for when doubling down on blue light defense.  

2. It Can Negatively Impact Performance

Extra-active, light-reactive lenses work by exposure to UV light and natural visible light. Blue light is part of the visible light range. When you combine a product designed to reduce blue light exposure with a product that works best with full exposure to that light, you’re going to have a problem.
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Perhaps the biggest advantage an extra-active photochromic offers over their traditional counterpart is their ability to retain color in the car. While car windows may filter out UV, they still allow natural light, including blue light, to pass through the window. That natural light is what enables an extra-active to retain some color in the car. When a blue light coating reflects blue light away from the lens, that’s less available light to darken the lens in the vehicle.

3. It Changes the Appearance

Adding a blue light coating to a light reactive lens creates an unintentional, and sometimes undesirable, mirror effect on the lens. So, a patient expects their lenses to look one way, and they end up looking entirely different. This creates a potential for a complaint or redo request. 

Wrapping It up to Go

Referring back to our supersized value meal comparison, more doesn’t always mean better…or necessary. When considering blue light filtration, it may seem like adding a blue-filtering coating to a light-reactive lens serves up a full course of defense, but doing so can result in more bellyaches than benefits.      

Related Content: How Much Blue Light Are those Lenses Really Reducing?