Blue-violet vs blue-turquoise light: which one do glasses filter?
By Spektrum Glasses Editorial Team · Published 2026-08-06 · Updated 2026-08-06 · Facts re-checked 2026-08-06 How this page is written and checked: our editorial method · how we verify claimsShort answer
Most blue light glasses filter blue-violet light near 400-450 nm, not blue-turquoise light near 465-495 nm. Our clear lens, measured per ANSI Z80.3, filters 99.99% at 400 nm but only 33.1% at 450 nm. Covering the turquoise band requires a visible amber, orange or red tint; a near-clear lens cannot do it.- Blue-violet is roughly 400-455 nm; blue-turquoise roughly 465-495 nm. The edges are convention, not physics.
- Our clear lens: 99.99% filtered at 400 nm, 95.1% at 410, 63.0% at 420, 33.1% at 450.
- Our amber evening lens filters 98.3% of the 460-480 nm band; orange filters 99.96% across 380-500 nm.
- Filtering turquoise light means absorbing visible blue, which always produces a visible yellow-amber tint.
- Orange and red lenses are not suitable for driving. Any percentage without a wavelength band is meaningless.
Where the two bands sit on the spectrum
Visible light runs from about 380 to 780 nm. The blue portion, roughly 380-500 nm, is not one uniform thing, and its two halves behave differently enough that they are usually given separate names. Blue-violet is the short-wavelength end, commonly drawn at about 400-455 nm. Blue-turquoise sits at about 465-495 nm. Those edges are a naming convention rather than a physical boundary. Different sources place them a few nanometers apart, and nothing about the light itself changes abruptly at 455 nm. What does change, continuously, is photon energy. Energy is inversely proportional to wavelength, so a 400 nm photon carries about 25% more energy than a 500 nm photon (roughly 3.10 versus 2.48 electron volts). That is the reason photochemical hazard weighting in photobiological safety work is concentrated at the violet end of the band and falls steeply as wavelength rises toward 500 nm. The turquoise end is interesting for an unrelated reason. Circadian signaling in the human eye is most sensitive not at the violet edge but in the blue-green region — the 460-480 nm window that our lab report labels the melatonin band. So the two halves of the blue band matter for two different reasons, and a lens that deals with one may do almost nothing to the other.What our measured lenses actually filter
Our clear lens was measured by COLTS Laboratories (report O-SPG111015), an A2LA-accredited lab operating to ISO/IEC 17025 under certificate 1612.01, using spectral transmittance per ANSI Z80.3. The published points show a filter that is essentially a violet-end cutoff:
The clear lens also transmits 91.6% of visible (photopic) light, which is what makes it near-clear with no heavy tint. The orange and red figures were measured in 2026 by our lens manufacturer’s optical laboratory rather than by COLTS. Neither the orange nor the red lens is suitable for driving, because both alter the appearance of colored signals and cut a large share of visible light.
Why a near-clear lens cannot cover the turquoise band
This is color physics, not a manufacturing limitation. Light at 480 nm is light your eye reads as cyan-blue. If a lens absorbs most of it, the light that reaches your eye is missing its blue-green component, and the lens looks yellow or amber. There is no way to remove a large fraction of 465-495 nm light and still have a lens that looks clear. Any lens marketed as clear is, by definition, letting most of the turquoise band through. Our measured numbers show exactly that shape. Filtering falls from 99.99% at 400 nm to 63.0% at 420 nm to 33.1% at 450 nm. The published points we quote stop at 450 nm, and the curve is still descending there, so filtering in the 465-495 nm turquoise region is lower again than 33.1%. Meanwhile visible transmission stays at 91.6%. The ZENOX clear lens is the same story stated as a single figure: about 52% averaged across the blue band, with 100% UV filtering. An average across 380-500 nm hides a steep curve — heavy filtering at the violet end, light filtering at the turquoise end. That is why a band-averaged percentage is a weaker number than a per-wavelength table, and why we publish both.Which band you would want filtered, and when
For daytime use, the violet end is the part a near-clear lens can address without changing how colors look. You keep normal color discrimination, normal brightness, and a lens that is legal and practical for driving. Our clear lens is that design: near-total filtering at 400 nm, tapering off well before the turquoise band, plus more than 99.99% of UVA and UVB. For evening use, the band of interest moves to 460-480 nm, and a clear lens is the wrong tool. Our amber evening lens filters 98.3% of that window and 97.9% across 400-500 nm; the orange lens reaches 99.96% across 380-500 nm. Those figures come at the cost of a strong visible tint and colors that look wrong, and again, orange and red lenses should not be worn for driving. It is worth being blunt about scale here. If your goal is to reduce how much short-wavelength light reaches your eyes in the evening, the size of the source usually dominates the lens. Screen brightness, room lighting, viewing distance and how late you are looking at a bright display all change the amount of light arriving at your eye by far more than a filter does at wavelengths where that filter passes two-thirds of the light. A tinted lens is a real optical filter; it is not a substitute for turning the lights down.What the evidence supports and what it does not
Transmittance is measurable, repeatable and boring, which is why we publish it. What a filtered percentage cannot tell you is what happens to a person wearing the lens. The one external result we cite is Leung, Li and Kee, “Blue-light filtering spectacle lenses: optical and clinical performances”, PLOS ONE, 2017. Across commercially available blue-light-filtering lenses, it found a reduction in the calculated blue-light hazard of roughly 10-24%. Read that carefully: the blue-light hazard is a weighted optical calculation over the spectrum, not a clinical outcome. A 10-24% figure is also a long way from the headline percentages that marketing tends to quote, because those headline numbers are usually a single wavelength at the violet end where filtering is highest. On the question of whether wearing a filtering lens changes how people feel or function, the evidence for symptom benefit is limited and contested, and we are not going to pretend otherwise. Our lab data describes the lens. It does not describe you. Anyone quoting a spectral number as if it settled a downstream question about the wearer has changed the subject, and any page promising a symptom outcome from a transmittance measurement is promising something the measurement cannot support.How to read a filtering claim
Three questions separate a real number from a decorative one.- Over what band, or at what wavelength? “Blocks 99%” with nothing attached is not a claim, it is a shape. Our clear lens is both 99.99% and 33.1% depending on which wavelength you point at.
- Measured by whom, to what standard? Spectral transmittance to ANSI Z80.3, run by a lab accredited to ISO/IEC 17025, is checkable. An unattributed number is not.
- Is it a peak, an average, or a curve? A peak flatters a violet-end filter. An average hides the taper. A per-wavelength table is the only version you can reason with.