Frequently asked questions

Can I buy something called UV+420cut™ lenses?

No. UV+420cut™ is the brand name of a particular technology. Mitsui Chemicals supplies lens manufacturers with the material that forms the basis of that technology as well as ophthalmic lens materials.


Are "computer glasses" the same as glasses made with UV+420cut™ technology?

No, they are not. Typical computer glasses are made to block the blue light emitted by computer monitors and smartphones. Lenses with UV+420cut™, on the other hand, block everything in the short wavelength part of the spectrum, from UV up to 420 nm, for protection of the eyes on a daily basis.


Would glasses with UV+420cut™ technology be considered sunglasses?

If we define sunglasses as eyewear that reduces glare through the use of colored lenses, then the answer is no. With that said, glasses made with UV+420cut™ technology are a good choice for everyone from young children to seniors, because they just block UV and high energy blue light and won't make everything dark.


Do glasses with UV+420cut™ technology block blue light?

So-called "blue light" is high-energy visible light with wavelengths ranging from 400 nm to 500 nm, and UV+420cut™ technology does not block this part of the spectrum. UV+420cut™ does block that part of the spectrum with the highest energy, namely 400–420 nm light.
The peak wavelength of the blue light emitted by computer monitors and smartphones is around 460 nm. If you want to block this light, you can get lenses made with an additional blue light coating.


Should children have glasses made with UV+420cut™ too?

Young people normally show little clouding of the eyes and have transparent corneas and lenses. Light can pass through more easily, which means the retina is more susceptible to damage. It's important to protect the corneas, lenses and retinas from the sun's UV rays from a young age, and glasses made with UV+420cut™ can help.


Will glasses made with UV+420cut™ affect my circadian rhythms?

UV+420cut™ should have no effect on the circadian rhythms (body clock) because it does not block 488 nm light, which research has shown to wake the body up.


Does Mitsui Chemicals make actual lenses?

As our name implies, Mitsui Chemicals is a chemicals manufacturer. What we do is supply lens manufacturers with materials and technologies for making corrective lenses, as well as materials and technologies for making UV+420cut™ lenses. Our corrective lens materials have set the standard for high RI (refractive index) plastic lenses, which are sold worldwide under the MR™ brand.