LENS GUIDE

What does UV400 mean on sunglasses?

UV400 is commonly used to describe lenses intended to block ultraviolet light up to wavelengths of 400 nanometers, covering UVA and UVB ranges. It is a lens-protection claim, not a description of how dark the lens looks.

UV and visible light are different

The tint you see controls visible light. UV filtering concerns wavelengths outside most visible light. That is why a very dark lens is not automatically more protective than a lighter lens.

UV400 and polarization are not the same feature

Polarization targets reflected glare. UV400 refers to ultraviolet filtering. They can coexist, but one label does not automatically imply the other.

Why verified specifications matter

Eyewear marketplaces often contain broad marketing language. We prefer to surface claims conservatively. If a supplier specification does not clearly support a feature, we do not treat that feature as established just because a similar-looking product may offer it.

What to check before buying

Look for clearly stated UV specifications, lens type, polarization status when relevant, frame dimensions, and any testing or certification information supplied with the product. For eye-health concerns or specialized protection, consult an optician or eye-care professional rather than relying only on fashion-product labeling.