UV400 Sunglasses: What OEM & Wholesale Buyers Must Spec
Almost every buyer I quote asks whether the lenses are polarized. Far fewer ask whether they are UV400 — and only one of those two questions is about the wearer's health. Here is what UV400 actually means, why it is the line between a legitimate product and a liability, and how to verify it before you commit to a container.
UV400 for Buyers at a Glance
$0.15–$0.25 per pair
UV400 add-on cost
400 nm
Standard cut-off
Category 3 (8–18%)
General daylight category
under $100
UV transmission meter
What UV400 Actually Means
UV400 is a number, and the number is the whole point. Ultraviolet radiation runs in wavelengths below the visible spectrum — UVB from about 280–315 nanometres, UVA from 315–400. A lens rated UV400 blocks everything up to 400nm, which means it filters effectively all the UVB and UVA that reaches the eye. That is the highest practical protection rating in the trade; there is nothing meaningfully above it.
The critical thing for a buyer to internalise is that UV400 is a protection standard, not a tint. It says nothing about how dark the lens looks. A perfectly clear lens can be UV400, and a very dark lens can carry no UV rating at all. This is why judging sunglasses by darkness is a mistake — protection is a coating and material property, not a shade of grey.
That distinction is not academic. It means the cheap, dark, unrated lenses you will inevitably be offered can be actively worse than nothing. Behind a dark tint, the pupil dilates to let in more light; if the lens blocks no UV, the eye absorbs more ultraviolet than it would with no sunglasses at all. A UV400 rating is what turns a tinted lens from a hazard into a product.
UV400 vs Polarized: Why Buyers Conflate Them
In every quote conversation, the word that comes up first is polarized. Buyers ask for it because consumers ask for it, and it has become a proxy for quality. But polarized and UV400 answer two completely different questions, and confusing them is how brands end up selling a health product that does not protect.
Pros of UV400 (protection)
- ✓Blocks UVA and UVB up to 400nm — the health spec
- ✓Adds only $0.15–$0.25 per pair at wholesale
- ✓Independent of tint darkness — a clear lens can be UV400
- ✓Verifiable in seconds with a cheap meter
Cons of UV400 (protection)
- ✕Does not cut glare or reflected light
- ✕Cannot be visually verified by the wearer
Pros of Polarized (glare reduction)
- ✓Cuts glare off water, roads and snow — the comfort spec
- ✓A premium feature consumers recognise and pay for
- ✓Pairs naturally with UV400 in a full-spec lens
Cons of Polarized (glare reduction)
- ✕Adds roughly $0.80–$2.00 per pair at wholesale
- ✕Provides no UV protection on its own
- ✕Heavily mislabelled in the low-cost tier
The correct framing for an order is: UV400 is the floor, polarization is the upgrade. Specify UV400 on every lens without exception, then decide per SKU whether to add polarization. Do not let a supplier substitute one for the other, and do not assume that a lens sold as "polarized" is automatically UV-protective — in the cheaper tiers, it frequently is not.
There is also a colour-filter distinction worth knowing: polarized lenses reduce horizontal reflected glare, while the brown or grey tint of a lens changes how colours appear and how much visible light passes through. Tint darkness is captured by the lens category (Category 1–4), which is separate again from both UV400 and polarization. Our polarized vs UV400 breakdown goes deeper on the consumer-facing side.
How to Verify UV400 Before You Order
Spec sheets lie — not always maliciously, but often. Resin batches change, suppliers relabel, and a buying agent may pass on a specification it never independently checked. For a spec this important, verification is not optional, and it is cheap.
Use a UV transmission meter. These handheld devices shine UV through the lens and display the transmittance percentage. They cost well under $100, take seconds per lens, and give you a hard number instead of a claim. A genuine UV400 lens will read at or very near zero UV transmittance. Buy one, learn it, and test every new lens type and every new supplier.
Test samples and production runs separately. A sample can be perfect while a mass-production lens drifts. Ask for a random pair from the production run, or arrange third-party testing, before final payment.
Request the test report. For US-bound orders, UV transmission testing sits alongside FDA impact-resistance requirements. For Europe, EN ISO 12312-1 governs UV transmittance and lens categories. A real factory can supply current test reports; a trading company usually cannot.
What to Write in Your OEM Spec
The gap between a protected lens and a decorative one closes with one document: your specification. Every UV400 order should carry these lines explicitly, because the factory builds to the sheet, not the intention.
Protection: "UV400 — blocks 100% of UVA/UVB up to 400nm," stated as a requirement, not a hope. Do not accept "UV protection" as a substitute; it is vague enough to mean 380nm.
Lens category: Category 3 (8–18% light transmission) for general daylight use in most markets. Category 4 (3–8%) only for high-altitude or open-water use, and note it is illegal for driving in the EU and many other regions.
Polarization: specify yes or no per SKU, with the added cost acknowledged.
Testing: request UV transmission test results and, for the US, FDA impact-resistance compliance. Ask for the report with the shipment.
Labelling: confirm the country of manufacture declaration and any required marking for the destination market, so customs clearance is smooth.
Get those five lines right and UV400 stops being a line item you confirm at the end and becomes the credibility your brand is built on. It costs a fraction of a cent per pair more than the alternative, and it is the difference between sunglasses you can sell with confidence and sunglasses you hope nobody tests.
Frequently Asked Questions
What does UV400 actually mean on sunglasses?
UV400 means the lens blocks light wavelengths up to 400 nanometres, which covers the entire UVA range plus UVB. In practice it means virtually all the ultraviolet radiation that reaches the eye is filtered out. It is a protection standard and is completely independent of how dark the lens looks — a clear lens can be UV400.
Is UV400 the same as polarized?
No, and this is the most common confusion in the trade. UV400 describes UV protection; polarized describes glare reduction from reflected light. They are separate technologies and neither implies the other. Many cheap lenses advertised as polarized carry no UV400 rating, and many good UV400 lenses are not polarized. A proper order specifies both explicitly.
How do I verify UV400 on a bulk order?
Use a UV transmission meter on samples. These devices cost under $100, take seconds per lens, and give a numeric reading of UV transmittance. Relying on a spec sheet alone is risky because mislabelling is common in the lower tiers of the market. Spot-check every new supplier and every new lens type before you commit to volume.
Should every wholesale order include UV400?
Yes, if you are selling into any market with meaningful sunlight. UV400 adds only $0.15–$0.25 per pair at wholesale, and shipping tinted lenses without it is genuinely harmful to the wearer — a dark lens with no UV filter makes the pupil dilate and admits more UV than wearing nothing. Treat UV400 as a baseline, not an upsell.
Does UV400 sunglasses need to be polarized?
Not necessarily, but most buyers add polarization for outdoor and sport ranges because it cuts glare off water, roads and snow. Polarization adds roughly $0.80–$2.00 per pair at wholesale. The essential spec is UV400; polarization is the premium upgrade on top of it.
Sourcing UV400 Lenses for Your Brand?
Send us your spec — frame, lens category, quantity — and we'll quote UV400 sunglasses at factory pricing, with test reports included.
Request a Quote