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Sunglasses and blue-light lenses — what UV400 and lens coatings actually guarantee, checked against standards.

Dark sunglasses resting on a sunlit table

What UV400 Actually Guarantees on a Sunglasses Label

UV400, polarized, category 3 — the three numbers on a sunglasses label do very different jobs. What each one means, which one protects your eyes, and the cheap test that catches fake claims.

Sep 19, 2026 · Updated Sep 19, 2026