01 · VISIBLE LIGHT
A darker lens transmits less visible light
As tint density increases, less visible light reaches the eye.
That is why the scene appears darker.
A dark lens primarily means that less visible light reaches the eye. Ultraviolet radiation lies outside the visible spectrum at shorter wavelengths, so visible darkness and UV attenuation do not have to change together. A nearly clear lens can still provide high UV attenuation through its material or added absorbers.
02 · ULTRAVIOLET
UV is a different wavelength region from visible light
UV performance depends on how much ultraviolet radiation the lens material and treatments absorb or block.
A clear appearance does not mean UV protection is absent.
UV performance is determined by measuring how much radiation the lens transmits across the relevant ultraviolet wavelengths. A visible tint percentage or colour cannot be converted directly into UV protection. Reliable products should provide performance information tied to an applicable sunglass standard or manufacturer test method.
03 · UV400
UV400 generally refers to protection extending to about 400 nm
The term is commonly used for products designed to block ultraviolet wavelengths up to roughly 400 nm.
Labelling and test standards can vary by market and product, so verified UV transmittance or a trustworthy test specification is more informative than a sticker alone.
UV400 is widely used in the market to describe protection extending to about 400 nm, but the label itself is not a single worldwide certification or test protocol. Compare the stated wavelength range, test basis and applicable standard rather than relying on a sticker alone. General-use sunglasses are covered by standards such as ISO 12312-1.
04 · DARK LENS
Darkness does not automatically guarantee UV protection
A lens can reduce visible light strongly while its UV performance still needs to be verified.
Visible-light filtering and UV absorption are separate optical characteristics.
A very dark lens can be useful for reducing visible glare, but darkness itself is not evidence of UV protection. This is why an unverified dark lens should not be assumed to be protective simply because the world looks dimmer through it. Visible-light attenuation and UV attenuation must be verified separately.
05 · CLEAR LENS
Clear spectacle lenses can also block UV
Lens material itself or an added UV absorber can reduce UV transmission.
The protected wavelength range varies by material and product, so check the specification.
Clear ophthalmic lenses can also attenuate substantial amounts of UV depending on the substrate, index and UV-absorbing technology used. The range is product-dependent, so not every clear lens should be assumed to provide identical protection. Transparency is not a visual test of UV performance.
SOLUTION GUIDE
When checking UV protection
Use it to judge visible brightness and glare control.
Verify it separately.
Check their actual UV-transmission specification.
GLANOS LENS CHECK
Separate tint density from UV protection
If both functions matter, verify both rather than assuming one from the other.
CAUTION
Do not assume a black or very dark sunglass lens automatically provides adequate UV protection
Use reliable product specifications or testing information.
GLANOS EYEWEAR
There is a reason glasses feel uncomfortable.
UV400 · UV protection · sunglasses · clear lenses · ultraviolet · spectacle lenses