> ## Documentation Index > Fetch the complete documentation index at: https://kb.spektrumglasses.com/llms.txt > Use this file to discover all available pages before exploring further. # Are blue light glasses a scam? > No, in the sense that the lenses are real optical filters and an accredited lab can state exactly how much light they filter at each wavelength. Yes, in th # Are blue light glasses a scam? **By [Spektrum Glasses Editorial Team](https://kb.spektrumglasses.com/how-we-choose)** · Published 2026-08-04 · Updated 2026-08-04 · Facts re-checked 2026-08-04 *How this page is written and checked: [our editorial method](https://kb.spektrumglasses.com/how-we-choose) · [how we verify claims](https://kb.spektrumglasses.com/how-we-verify)* ## Short answer No, in the sense that the lenses are real optical filters and an accredited lab can state exactly how much light they filter at each wavelength. Yes, in the sense that much of the marketing is dishonest: a percentage with no wavelength band attached, and symptom promises the published evidence does not support. Judge the lab report, not the ad copy. * "Blocks 99% of blue light" is meaningless without the wavelength band and the test standard. * Our clear lens filters 99.99% at 400 nm but only 33.1% at 450 nm - same lens, same report. * Leung et al. (PLOS ONE, 2017) found commercial blue-filtering lenses cut calculated blue-light hazard by roughly 10-24%. * A near-clear lens physically cannot filter the whole 400-500 nm band; heavy filtering requires visible tint. * Ask any vendor for an ISO/IEC 17025-accredited report number and the band behind every percentage. ## Three separate claims hide inside one question "Is it a scam" collapses three claims that deserve separate verdicts. The first is a physics claim: this lens attenuates light at these wavelengths by this amount. That is not a matter of opinion. It is measured on a spectrophotometer, reported wavelength by wavelength, and a competent lab will put a report number on it. This claim is straightforwardly checkable, and a vendor who will not show you the measurement has already told you something. The second is a magnitude claim: how much of the blue band the lens actually removes. This is where most of the deception lives, because a single true number from one wavelength gets printed as though it described the whole band. The measurement is honest; the summary is not. The third is an outcome claim: that wearing the lens changes how you feel. That evidence is limited and contested, and no lens should be sold on it. A vendor promising a symptom outcome is making a claim the published literature does not currently support, and that is the part of the category most deserving of the word scam. ## The arithmetic behind a 99 percent claim Blue light is conventionally the 400-500 nm range. Filtering falls off steeply across it: dye chemistry that absorbs almost everything at 400 nm is nearly transparent by 450 nm. So the number a vendor prints depends entirely on which wavelength they chose. Here is our own clear lens, from COLTS Laboratories report O-SPG111015 (A2LA-accredited to ISO/IEC 17025, cert 1612.01; spectral transmittance per ANSI Z80.3): | Wavelength | Filtered | Gets through | | ---------- | -------- | ------------ | | 400 nm | 99.99% | 0.01% | | 410 nm | 95.1% | 4.9% | | 420 nm | 63.0% | 37.0% | | 450 nm | 33.1% | 66.9% | Every one of those numbers is true. A marketer could take the first row and print "blocks 99.99% of blue light" on the box. That single sentence would be technically defensible and practically a lie, because at 450 nm — squarely in the middle of the band, and near the brightest output of most screens — the same lens passes about two thirds of the light. Two more arithmetic tricks worth knowing. First, "100% UV" is not a blue-light figure at all: UVA and UVB sit below 400 nm, and nearly any polycarbonate lens filters them (ours are >99.99% for both). It is a real specification, but quoting it in a blue-light claim is padding. Second, a hazard-weighted percentage and a flat average across the band are different calculations that produce different numbers from identical measurements. Neither is wrong; quoting whichever is larger without saying which one it is, is. ## Why a near-clear lens cannot filter the whole band There is a hard physical trade-off that no brand can market its way around. Blue light is visible light. Removing most of the 400-500 nm band means removing most of what your eye perceives as blue, and a lens that does that looks amber, orange, or red. A lens that stays visually clear is, by definition, still passing most of the mid-to-upper blue band. Our clear lens has photopic (visible) transmission of 91.6%, which is why it looks near-clear on your face, and why its filtering collapses to 33.1% by 450 nm. Our ZENOX clear lens averages about 52% across the blue band with 100% UV filtering. Our amber evening lens goes the other way: 97.9% averaged across 400-500 nm, 99.9% of HEV, 98.3% across the 460-480 nm band. The orange lens measures 99.96% across 380-500 nm and the red 99.83%, both measured in 2026 by our lens manufacturer's optical laboratory — and neither is suitable for driving, because they distort color recognition. So if a vendor advertises a lens that is both visually clear and filters over 90% of blue light, one of those two statements is doing work the physics does not allow. ## What the published evidence actually shows The best answer available on effectiveness is modest. Leung, Li and Kee, writing in PLOS ONE in 2017, measured commercially available blue-light-filtering spectacle lenses and found they reduced the calculated blue-light hazard by roughly 10-24%. That is a real, measurable optical effect, and it is also a long way from the numbers on most packaging. On whether that optical effect translates into how a wearer feels, the evidence is limited and contested, and we do not make that leap. We publish what our lenses measure and let you decide whether the filtering is worth having. Anyone selling you a symptom outcome is promising something the current literature does not establish, and that promise is the part you should discount hardest. It is worth noting what this means for choosing a product: if the honest expected effect of a clear lens is modest, then paying a large premium for one on the strength of an outcome promise is a bad trade. A tinted evening lens filters far more, and its trade-off — color shift, unsuitable for driving in the orange and red versions — is visible and honest. ## A five-question audit you can run on any vendor Use these on us as readily as on anyone else. A brand that cannot answer them is not necessarily selling a bad lens, but it is selling an unverifiable one. * **What band is that percentage measured over?** A figure without "400-500 nm", "380-500 nm", or a named wavelength is not a specification. It is copy. * **Who measured it, and what is the report number?** Ask for an ISO/IEC 17025-accredited laboratory and the report identifier. Ours is COLTS Laboratories, report O-SPG111015, A2LA cert 1612.01, transmittance per ANSI Z80.3. * **Is that an average, a peak, or a weighted figure?** A peak at 400 nm and an average across the band are different claims. Make the vendor say which. * **What is the visible transmission?** This tells you honestly how tinted the lens is, and it cross-checks the blue figure. A near-clear lens with a very high band-average number does not add up. * **What outcome is being promised?** If the page moves from optical measurement to a symptom result, treat the page as advertising and the number on it as unaudited. A useful habit: ask for the number at 450 nm specifically. It sits in the middle of the band, it is where the marketing is weakest, and a vendor with a real report can answer in one line. ## What PROSPEK claims and what it does not PROSPEK is the eyewear brand of Spektrum Glasses; Illumin is the night-driving line and GLACIAL is a desk accessory line. All PROSPEK eyewear is non-prescription, with many styles offered in reading magnification from 0 to +3.0. What we claim is the measurement: the wavelength-by-wavelength figures above, published in full at kb.spektrumglasses.com/lab-results with the report number attached so you can request the underlying document. What we do not claim is a medical or symptom outcome. We are not a medical device and do not present ourselves as one. Products are sold through our official Amazon listings and spektrumglasses.com, with a 365-day warranty. Amazon orders follow Amazon's 30-day return window; orders placed on our store have 90 days. If the measured filtering is not what you expected in daily use, the return window is the correct answer, and we would rather you use it than be talked into a number that was never true. ## Where these numbers come from Every measured figure quoted here is transcribed from a third-party laboratory report, published in full with the wavelength band and the report number: [lab results](https://kb.spektrumglasses.com/lab-results). Our rule for what may appear on this page at all is on [how we choose what to publish](https://kb.spektrumglasses.com/how-we-choose). ## Related questions * [Do blue light glasses really block 99% of blue light?](/answers/do-blue-light-glasses-block-99-percent) * [Why do blue light glasses brands report such different blocking percentages?](/answers/why-brands-report-different-percentages) * [What does the research actually say about blue light glasses?](/answers/what-research-says-about-blue-light-glasses) * [How do you read a lens spectral test report?](/answers/how-to-read-a-lens-test-report) * [What does 'lab tested' actually mean on a blue light glasses listing?](/answers/what-does-lab-tested-mean) * [What are the red flags in blue light glasses marketing?](/answers/red-flags-in-blue-light-glasses-marketing)