What Does UV400 Mean? (And Why It's on Every Pair)
Shopping for glasses — blue light, sunglasses, or both — you'll see "UV400" stamped on nearly every pair. It's one of the few specs on a lens that's genuinely worth caring about. Here's what it means.
UV400 in one sentence
UV400 means the lens blocks light up to a wavelength of 400 nanometers — which covers essentially all UVA and UVB rays. That's the full range of ultraviolet light that reaches your eyes from the sun.
The "400" is the cutoff point. UV light lives below 400 nm; visible light starts above it. A UV400 lens draws the line right at the edge of what you can see, blocking the invisible, higher-energy stuff while letting normal light through.
Why UV protection actually matters
This is the part that separates UV protection from the blue-light debate. The evidence that UV light can harm your eyes over time is solid and long-established. Cumulative UV exposure is linked to several eye conditions and to damage of the delicate skin around the eyes.
Unlike the murkier claims around screen blue light, blocking UV is straightforwardly good for your eyes — the same way UV protection matters for your skin. It's protection against a known risk, not a maybe.
UV400 vs. "blue light blocking"
These are two different things, and it's worth keeping them straight:
UV400 blocks invisible ultraviolet light — the genuinely protective, daylight-relevant part. It's most important outdoors.
Blue light filtering reduces some of the visible high-energy blue light from screens and LEDs — more of a comfort-and-sleep feature, most relevant indoors and in the evening.
A good pair can do both. The point is that UV400 isn't marketing fluff — it's the spec doing the real protective work when you're out in the sun.
The BHG standard
Every single pair in our lineup is UV400 — blue light glasses and sunglasses alike. We treat full UV protection as a baseline, not an upgrade, because it's the part of the lens that's actually defending your eyes against a known hazard.
See the full range in the Glasses Collection — pick by the look and tint you want, knowing the UV protection is handled on every pair.