Reviews Looking Ahead: New Advancements In Eye Protection & Enhancement Rob Curtis January 13, 2023 Join the Conversation NEXT-GENERATION EYEPRO GIVES YOU THE EDGE You’re leaving shooting performance on the table if you’re using old-school lens tints. Next-generation eyepro lens tint technology has vision-enhancing benefits that leave old-school monochromatic base tints in the dust. These new tints combine recent advances in our understanding of human vision with new dye development technologies. The result is eyepro that enhances contrast and color perception in ways that improve your ability to observe and react. Don’t take our word for it, we’re hearing that the U.S. Army wants to modernize its eyepro program and is currently asking folks in the eyewear industry for their ideas on performance-enhancing lens tints that it can use as an alternative to its current-issue smoke and clear lenses. The Army currently only fields clear and smoke-tinted lenses because these provide the most color-accurate view of the battlefield. But advances in tint technology in mil-spec ballistic eyepro has the Army evaluating the benefits of higher contrast lenses afforded by more modern lens tints. After some explaining of what we’re dealing with, we’ll take a look at the three biggest brands in the military eyepro space (Oakley Standard Issue, Revision Military, and Smith Optics Elite) that are deploying next-gen lens tint technology in their mil-spec offerings. LEGACY EYEWEAR When they were invented in the 19th Century, sunglasses were only used to shield people’s eyes from the bright sunlight that caused them to squint. While this idea of glare protection remains a key function of modern eyewear, science has heavily added to the list of features we expect from a modern set of shades. Color response of the eye.jpg This chart shows how intensely the human eye perceives different wavelengths of light. The taller the line, the more intense our perception of light at that wavelength, or color. At the most basic level, modern sunglasses prevent eye damage and disease by protecting our eyes from the harmful ultraviolet (UVA and UVB) spectrum of light that exists below the range of our vision. Monochromatic tints are added as adulterates to the lens material to alter the way we see the world, and polarizing technology can be included to reduce further particularly harsh glare that comes from reflective surfaces. As lens materials progressed from glass to more durable polycarbonates, lenses now protect our eyes from debris and penetrating objects. And, with the addition of surface coatings, lenses can resist scratching and fogging. Curtis Shooting Modern lens tints present a higher contrast view and make key colors in the landscape stand out, making it easier to notice and judge changes in terrain. Despite all this technological progress surrounding sunglasses, little changed in the way we used lens tints until about ten years ago. Before then, lensmakers could apply colors to lenses and filter broad parts of the spectrum, making gross changes to the way we see the world. The idea was that removing our ability to see a certain color made the adjacent colors in the spectrum stand out more. This results in increased visual contrast. (This principle of the tinting concept is valid and is still used today, but in a much more refined manner… more on this later.) Looking at traditional, monochromatic tint technology now, we can see some obvious drawbacks. First, last-generation dyes cast a wide filter over a large chunk of the spectrum. When a wavelength of light (color) is filtered, that color becomes faded and harder to see. Additionally, broad-colored lens tints shift the colors we see and reduce our ability to evaluate color accurately. In turn, this also forces our brain to correct colors back to how we expect them to appear, causing eye fatigue and increasing the cognitive load on the brain. To summarize, our vermilion Ray-Bans make everything orange, slow down our reaction time (slightly), and make our eyes and brain tired. Generic Orange Color Volume Chart: This color volume chart shows how a vermilion (orange) tint emphasizes certain colors while sacrificing the ability to see others. The vermilion lens shows the colors in the green circle while the naked eye sees the area of color in the black circle. MILITARY BALLISTIC EYEPRO This adherence to color-neutrality (or color accuracy) is why the U.S. Army has, for decades, put only smoke (a.k.a. gray) or clear lenses on the faces of soldiers. Smoke tint is color-neutral and has no effect on the colors we see while it still reduces the amount of glare-producing visibly transmitted light (VLT) that would otherwise cause us to squint. Since accurate and timely observation is a basic soldier task, it’s not hard to figure out why the Army brass has stuck with neutral-colored lenses and been reluctant to issue rose-colored glasses to soldiers. Generic Grey Color Volume Chart: This color volume chart shows how a smoke (gray) tint faithfully represents colors to the human eye. The smoke lens shows the colors in the green circle while the naked eye sees the area of color in the black circle. Taking a step away from tint for a second, let’s look at what makes eyewear “eyepro.” In order for the military to issue protective eyewear, it’s gotta meet certain criteria laid out in its MIL-PRF-32432A specifications. MIL-PRF (for short) is a rubric of testing that certifies a set of eyewear will protect our eyes from the hazards of the battlefield. It assumes the eyewear has already met the commercial ANSI Z87.1 standards of protection that pertain to the kind of protective eyewear for sale at Home Depot. To get from ANSI Z87.1 (including Z87+) to MIL-PRF the military adds a few, more stringent tests. For this article, we’ll oversimplify things and point out that MIL-PRF-rated eyewear has to be color-neutral and absorb about 50% more impact energy than ANSI Z87.1 eyewear. Additionally, MIL-PRF testing uses a more aggressive projectile in its high velocity projectile test that’s sharper and meant to simulate explosive fragments instead of the smooth steel ball used in ANSI’s high velocity testing. So, when shopping for eyepro, be aware that Z87.1 (and Z87+) gear will do the job in most situations, but the MIL-PRF rating offers a higher level of impact protection required by the U.S. military. Traditional Tint Technology Monochromatic tints that are becoming outdated because of the performance-enhancing benefits of next-generation lens tints: Clear – UVA and UVB protection. Color-neutral. Negligible VLT reduction. Smoke/Gray – Color neutral. Reduces VLT without color shift. Amber/Brown tints – Increases contrast. Warms landscape. Causes color distortion. Blue – Makes orange targets stand out. Causes strong color distortion. Vermilion (Orange) – Increases contrast more. Causes color distortion. Yellow – Blocks all blue light. Thought to be good for snow and water scenes. Causes heavy color distortion making ability to judge color very difficult. Rose Copper – The first old-school “advanced” high contrast tint. Warmer with more contrast. Causes color distortion. To be fair, over the years, there have been valuable advancements in lens tint tech that gave folks a performance edge in certain situations. In a competition where we knew there was a single, critical color that was the key to success—like an orange clay in sporting clays, or a white-painted steel target in PRS shooting—we could use a traditionally tinted lens that made those key colors stand out. But these tints have a drastic effect on the way we see the other colors in these situations, and nobody likes looking at the world through a weird colored lens for long. The tradeoff might be worth it in some situations, but it’s not ideal. That’s what lead to the creation of the next-gen tints we’re talking about in this article. EARLY ADVANCEMENTS IN TINT TECHNOLOGY For a long time, the heart of the eyewear industry was (and probably still is) fashion. But, as companies in a crowded market sought to differentiate themselves from the competition, one of the things they did was dedicate resources to the scientific development of performance-enhancing lens tints. From left, Revision Verso, Oakley Prizm TR22, Smith ChromaPop Black tinted MIL-PRF-rated lenses. This meant combining timely advancements in vision and color science, dye formulation, athletic physiology, and environmental analysis in ways their predecessors and competitors hadn’t. A major step forward in this regard came when lens designers figured out how to gain granular control of the wavelengths of the light they filter. Instead of using a dye that filters a single, broad area of the spectrum, big brains in the R&D departments of some eyewear companies figured out ways to analyze and combine dyes in novel ways. These dye packages give lens designers fine control over the wavelengths they filter and the number of places along the spectrum they can apply these filters… meaning they can make large changes to multiple, small areas of the light spectrum that reaches the eye. This Chart shows the spectral transmission of light after it’s been filtered by each of four tints. Notice the flat curves of the traditional tints as compared to the more complex curve made by advanced dyes used in more modern tints as represented by the “Generic Color Enhancing Lens” line. To understand this concept, think of the spectrum of light as audio coming from a stereo and a lens as controlling the bass and treble frequencies. Old dye tech is like having two or three sliders, or just a bass and a treble knob, while new dye tech is like having a full-on frequency equalizer… you know, the old-school stereo component with a dozen sliders on it. In our analogy, the sliders control the amount of light that’s visible at certain point on the spectrum–all the sliders at the top simulate a clear lens and moving the sliders down filters light. The more sliders, the finer the control we have over the output. This breakthrough in dye formulation piggybacks on the understanding of the relationship between color and contrast; namely that absorbing the color of light that sits on either side of the spectrum from a color that color brighter. (That's the definition of contrast.) Combine granular spectral filtering with this concept of contrast enhancement and we have a way for tints to affect contrast with great precision. OAKLEY PRIZM TINTS To make the most of this control, Oakley’s Senior VP of Advanced Product Development Ryan Saylor says he figured out that color perception had an environmental component. He and his team used a hyperspectral camera to capture scenes, like a golf course, a shooting range, or a hiking trail, that would then be rendered as a huge table of color data. The white line is the volume of color seen by the naked eye, the outer circular line shows the expanded volume of colors visible through a Prizm TR22 tinted lens. With this data, Saylor says, “we could reverse engineer every color in that spectrum and understand what it does. Knowing what colors were in this environment, what colors were most important to the user, and what colors the human eye are most sensitive to, we took those three reference points and created a dye formulation that dictated what colors we wanted to let through the lens (or which colors we want to magnify) and which colors we were willing to get rid of to create that magnification.” Oakley Standard Issue’s Prizm TR22 tint in an M-Frame Alpha frame. Oakley used these tenants of precision dye formulation, spectral analysis, and vision science to make lens tints that increase contrast for specific uses and branded the resulting product “Prizm” technology. Using these principals, Oakley developed its Prizm TR22 (VLT 22, for bright sunlight) and Prizm TR45 (VLT 45, for low light) performance shooting tints with guidance and feedback from the U.S. Army Marksmanship Unit. The concept was also applied to develop tints that help golfers, maritime users, and even Formula 1 drivers perceive more contrast and perform better in their respective environs. Looking at Oakley’s website, they actually offer some 25-plus versions of the Prizm tints, each one optimized for an activity or environment. SMITH OPTICS CHROMAPOP FAMILY OF TINTS Smith Optics uses the principles of advanced dye-making in a simpler way than Oakley. Where Oakley’s Prizm shooting lenses filter light from three places on the spectrum and create a bespoke tint for specific uses, Smith’s ChomaPop tech filters it at two places and results in a more general-purpose tint tech. Smith uses advanced dyes to precisely place filters along the spectrum where the wavelengths of blue and green light meet and where red and green light meet. This graphic from Smith shows where ChromaPop tint filters light in the two places of the spectrum where human eyes are the most sensitive to color shifts, at the crossover points of blue, green, and red. The human eye has the hardest time discerning colors at these crossover points, says Smith Optics eyewear Category Manager Allison Flake, “so filtering that part of the light spectrum out makes those other colors that are adjacent on the spectrum actually more vibrant, more poppy, and more obvious to human eyes.” Smith’s ChromaPop Black tint in Arena Elite frame. At press time, Smith is still offering MIL-PRF-rated eyepro featuring ChromaPop tints under its “Smith Optic Elite” brand, but it’s phasing out its use of MIL-PRF testing as it sunsets its military eyewear division. Once dealers sell out of existing Elite products, ChromaPop equipped eyewear will only be available with ANSI Z87.1 levels of protection. REVISION MILITARY’S I-VIS TECHNOLOGY Revision Military’s I-VIS branded technology is the latest offering in high-performance MIL-PRF lens tints. Like the next generation Prizm and ChromaPop tints, I-VIS uses an advanced library of dyes to make fine adjustments to the spectrum of light reaching our eyes. This color volume chart shows the expanded area of color that Revision’s I-VIS Verso tint (green circle) offers over the naked eye (black circle). Where its approach primarily differs is in the method it uses to determine what wavelengths to filter and in the amount of data is draws upon to determine the ideal combination of filters to apply. Revision Military’s Verso tint in a Stingerhawk frame. Instead of using a slow, iterative development process of producing prototype lenses and testing them with users to see how well they work, Revision partnered with a company called Hue A.I. that uses artificial intelligence to develop its dye formulation. Instead of making a dye formula and then seeing how well it compares to the ideal performance characteristics it wants, A.I. allows Revision to define the performance characteristics it wants from the outset and let a supercomputer essentially reverse engineer the perfect dye formula that does its job without unwanted side effects. This results in tints that don’t impart a tiring color cast or prevent the transmission of colors that are important. While it’s hard to explain, it also results in tints that actually expand the range of colors that our eyes can see by applying a range of microfiltering nodes in many places across the spectrum. The second way I-VIS technology differs from its competitors is in the amount of data it draws on to determine how to filter light in each environment. Instead of using data from a spectral image to evaluate the most prevalent and important colors in a scene, Revision draws upon on a much larger dataset derived from NOAA weather and NASA satellites. Revision Military’s Senior Director of Product Sid Mitchell says, “comparing the level of data we use to make our lens tints to what our competitors use is like comparing the level of data in a framegrab to what we can do with the data from an entire video.” Rather than being designed to perform in a specific role, I-VIS tints are optimized according to the colors of a landscape, namely desert, jungle, alpine, overcast snow, bluebird snow, and urban scenes. CONCLUSION The best way to see the world is a massively subjective topic. But the way we measure the benefits of enhanced vision is objective. With the right eyepro, we can see and recognize more threats, see them faster, and react faster. Traditional, monochromatic lens tints served their purpose, but recent advances in vision science and computing have led us to a place where we can do far better than rose-colored glasses. If you take anything from this article, it’s that technical explanations and charts should show that there’s a difference in the next generation of eyepro tints but the only way to be truly convinced of what you’re missing is to try these tints yourself. Explore RECOILweb:Get RECOIL on Your Smartphone or Tablet[WATCH] RECOILtv All Access: Century Arms Draco NAK9The Controversial AR 15 Charging HandleTactical Distributors March Gear Girl (Pics+Video) NEXT STEP: Download Your Free Target Pack from RECOILFor years, RECOIL magazine has treated its readers to a full-size (sometimes full color!) shooting target tucked into each big issue. Now we've compiled over 50 of our most popular targets into this one digital PDF download. From handgun drills to AR-15 practice, these 50+ targets have you covered. Print off as many as you like (ammo not included). Get your pack of 50 Print-at-Home targets when you subscribe to the RECOIL email newsletter. 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