The European Committee for Standardization (CEN) published the revised EN 166 standard for personal eye protection in early 2025. While the 2001 version served industry for nearly a quarter century, the 2025 update reflects major advances in materials science, occupational health research, and worker feedback from thousands of incidents logged across Europe.
For B2B buyers and procurement teams, the practical question is: what changes on January 1, 2027 — when the 2025 revision becomes mandatory — and which product lines should you standardize on?
1. Stricter optical clarity (Class 1 enhancement)
The 2025 revision tightens optical class requirements. Where the 2001 standard allowed spherical power up to ±0.06 diopters in Class 1, the new standard reduces this to ±0.04 diopters. For workers wearing prescription glasses underneath — known as "over-spec" use — this delivers noticeably clearer peripheral vision and reduces eye fatigue over full shifts.
2. New lateral / side-impact test
EN 166:2025 introduces a mandatory side-impact test using a 6 mm steel ball at 45 m/s, simulating projectile strikes from oblique angles. Previously this was optional; it is now required for all "mechanical strength" markings S, F, B, and A. Importantly, marking "T" (for extreme temperature performance, −5°C to +55°C) is updated to include the new test sequence.
"The new EN 166 narrows the gap between European and ANSI Z87.1+ side-impact requirements — a positive development for global procurement teams standardizing on a single specification."
3. Field-of-view measurement standardized
For the first time, EN 166:2025 codifies a quantitative field-of-view (FOV) measurement. Eyewear must provide a minimum 70° horizontal binocular FOV. This particularly affects wrap-around goggle designs — some current models fall below this threshold and will require re-engineering.
4. Enhanced anti-fog performance test
The 2025 revision introduces an anti-fog test based on a 30-second steam exposure at 50°C ± 2°C. Lenses must retain ≥80% visible-light transmission post-exposure. Our internal testing already exceeds this — Safeworks SE-201 retains 87% post-steam — but the new test will disqualify many current budget goggles.
5. Updated marking & documentation requirements
Manufacturers must include a permanent QR code on the packaging linking to the EU Declaration of Conformity. CE marks must be at least 5 mm high. And every shipment must include a digital product passport accessible via the QR code.
How Safeworks is preparing
Our SE-201 Anti-Fog Safety Goggles and SE-301 Auto-Darkening Welding Helmet have been re-tested against the EN 166:2025 protocol since Q2 2026. Both pass with margin — see the highlights:
- SE-201: Optical Class 1, ±0.03 diopters; passes new side-impact; FOV 78°; anti-fog retention 87%.
- SE-301: Optical Class 1, ±0.025 diopters; passes new side-impact; FOV 82°; shade switching unaffected.
All units shipped after September 1, 2026 include the new QR-coded Declaration of Conformity at no additional cost.
What B2B buyers should do now
If your current supply contracts run through 2026, you're covered. For new RFQs and 2027-onward contracts:
- Confirm your supplier has a transition plan with documented test reports against EN 166:2025.
- Ask for digital product passport availability and QR-coded packaging.
- For ANSI Z87.1+ dual-standard requirements, ensure both standards are explicitly covered.
- Review legacy inventory that may need phase-out before December 31, 2026.
Safeworks sales and engineering teams are ready to support your transition. Reach out to our compliance team for product-specific test reports or to schedule a technical briefing.
