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Do blue light glasses block UV?

By Spektrum Glasses Editorial Team · Published 2026-08-16 · Updated 2026-09-11 · Facts re-checked 2026-09-11 How this page is written and checked: our editorial method · how we verify claims

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Short answer

Yes, but UV filtering and blue light filtering are separate optical properties measured at different wavelength bands. Our clear PROSPEK lens filters over 99.99% of UVA and UVB (COLTS Laboratories report O-SPG111015), while the same lens filters only 33.1% at 450 nm - a lens can block nearly all UV and still filter little of the visible blue band.

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UV and blue light are different filtering jobs

Ultraviolet (UV) light sits just below the visible spectrum, roughly 280-400 nanometers, split into UVB (280-315 nm) and UVA (315-400 nm). Blue light is visible light, roughly 400-500 nm, and the sub-band most discussed in the blue-light-glasses category is high-energy visible (HEV) light, the part of that range closest to violet. A coating that filters UV and a coating that filters blue light are doing two different jobs at two different parts of the spectrum. A lens can filter nearly all UV and only a modest share of blue light, or the reverse. That is why the two figures have to be reported separately with the wavelength attached. A claim like “blocks 99% of harmful light,” with no band named, could describe either end of that range, or neither — it is not a usable spec, and it is exactly the pattern this page exists to avoid.

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What our lenses measure for UV

Our clear lens was tested by COLTS Laboratories (report O-SPG111015, A2LA-accredited to ISO/IEC 17025 under accreditation certificate 1612.01), with spectral transmittance measured per ANSI Z80.3. Both UVA and UVB were filtered at greater than 99.99%. At 400 nm, the boundary between UV and visible light, filtering was still 99.99%. Visible (photopic) transmission on that same lens was 91.6%, which is why it reads as near-clear rather than tinted. The UV filtering comes from the lens coating, not from darkening the lens — a clear lens and a heavily tinted lens can filter UV to the same degree.

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Blocking UV does not tell you what happens to blue light

UV filtering and blue-light filtering can move independently of each other in the same piece of glass. Our ZENOX clear lens filters 100% UV while filtering about 52% of the blue band on average — full UV filtering paired with partial blue-light filtering, in a lens that looks clear. The PROSPEK clear lens shows the same pattern read the other direction: filtering falls off sharply as wavelength moves past the UV boundary. At 410 nm it is 95.1% filtered, at 420 nm 63.0%, and at 450 nm 33.1% — well into the visible blue range and far below the greater-than-99.99% figure at 400 nm. A single unqualified “blocks UV” or “blocks blue light” claim could be describing either end of that curve, which is why we publish the wavelength next to every number.

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How our tints compare on blue-band filtering

Filtering strength across the 400-500 nm blue band, and the visible-light transmission that goes with it, varies by tint. All figures below are from COLTS Laboratories report O-SPG111015 except orange and red, which our lens manufacturer’s optical laboratory measured separately in 2026. Orange and red filter nearly the entire 380-500 nm band, which is also why neither is suitable for driving — cutting that much light reaching the eye works against the vision a driver needs at night.

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What ANSI Z80.3 does and doesn’t cover

All three samples in the clear-lens group of COLTS report O-SPG111015 passed ANSI Z80.3 testing for transmittance and chromaticity, and the lens is classified filter category 0, a cosmetic (non-absorptive) lens under that standard. ANSI Z80.3 governs light transmittance and color, and nothing else. It does not test or certify the accuracy of a reading power, and a lens passing it says nothing about magnification performance. When a listing or a review pairs a transmittance standard with a claim about the reading strength, those are two unrelated tests being described as one.

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Where the blue-light health claims stand

UV filtering is a straightforward optical measurement with an established test method — the numbers above are exactly that. The broader claims made about blue-light filtering and health outcomes are on much less solid ground, and worth separating from the UV question entirely. Leung, Li and Kee (PLOS ONE, 2017) found that commercially available blue-light-filtering lenses reduced the calculated optical blue-light hazard, a hazard-weighted measure across the blue portion of the visible spectrum, by roughly 10-24% — a lab measurement of light reaching the eye, not a clinical outcome. A 2025 Frontiers in Neurology meta-analysis of three randomized crossover trials (n=49, actigraphy-measured) found sleep onset latency, total sleep time, sleep efficiency, and wake-after-sleep-onset were all statistically non-significant; the authors describe current randomized-trial evidence as not supporting a meaningful effect, while noting the trials run so far may be too small to rule a small one out. A January 2026 review in Therapeutic Advances in Ophthalmology (Khorrami-Nejad et al.) found minimal or no significant difference in contrast sensitivity, color discrimination, or task performance versus standard lenses, and describes the evidence on eye strain and circadian outcomes as unresolved. None of that changes the UV numbers above, which are a separate, well-measured property. But it means a lens that filters UV effectively is not, by that fact alone, doing anything proven about screen strain, sleep timing, or eye health more broadly — those are open questions the current research has not settled.

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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. Our rule for what may appear on this page at all is on how we choose what to publish.

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Related questions

• Clear vs yellow (amber) blue light lenses: what is the difference?
• What do orange lenses do?
• What do red lenses do?
• Do clear blue light lenses actually work?
• What percentage of blue light should glasses block?
• Why do some blue light glasses have a yellow tint?

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A PROSPEK style for this