hat
Tèm nan "UV 400" endike longèdonn anba a ki se limyè a iltravyolèt bloke pa vè a. Yon pè linèt ak sa a make filtre UV-A, UV-B ak UV-C reyon paske longèdonn yo se anba a 400 nanomètr. Vizib limyè gen yon longèdonn ki rive jiska 780 nanomèt e konsa pénétrer nan linèt solèy sa yo.
eng
The term "UV 400" indicates the wavelength below which the ultraviolet light is blocked by the glass. A pair of glasses with this mark filters UV-A, UV-B and UV-C rays because their wavelength is below 400 nanometers. Visible light has a wavelength of up to 780 nanometers and therefore penetrates through such sunglasses.