Tokai Lutina and UV420 cut lens – new anti-blue light lenses

Tokai Optical Lutina & UV420 cut – new anti-blue light lenses

According to the wavelength of light, light is divided into ultraviolet, visible light, and infrared. The shorter the wavelength, the greater the energy. The wavelength of visible light is approximately between 400 and 700 nm . Within this range, the colors of light are arranged in the order from purple to red due to different wavelengths. Wavelengths thinner than 400nm are so-called ultraviolet rays. Short-term exposure to ultraviolet rays can cause keratitis, and long-term exposure to ultraviolet rays can cause cataracts.

Glasses wearer protected by glasses, it is rare for them have developed cataracts or UV related eye diseases when they get older.

However, visible light in the range of 400-420nm can also have a serious effect on the eyes. It can directly damage the cells of the retina and macula, causing macular degeneration. Damage to the retina and macula is irreversible. This high energy light can even penetrate some sunglasses and requires special technology to effectively block it. 

In recent years, Mitsui Chemicals, the world's largest supplier of lens raw materials, has developed UV420 cut lenses that can effectively absorb 94% of the high-energy violet-blue light in range of 400-420nm. 

The official website of Mitsui Chemicals UV420 has a very clean demonstration
http://uv420cut.com/performance/

For comparison of UV400 VS UV420 under high-energy purple-blue light, you can also refer to the following video

Tokai Optical Lutina - Artificial Lutein Lenses

Tokai Lutina is based on Mitsui Chemical 's UV420 cut material, and then adds its own technology for improvement.

The yellow spots on the retina have accumulated a large amount of lutein. Lutein helps protect the eyes from oxidation and high-energy light. It has the same function as UV420 cut, so Tokai named its UV420 cut lens Lutina (lutein lens).