PERLA burgundy sunglasses

Like almost everything in the world, light is also a wave. The color our brain assigns to the waves detected by our eyes is determined by the wavelength of the light. The wavelength of visible light ranges from 400 to 700 nanometers – 700 nm is red, and 400 nm is violet. This is the range of the electromagnetic spectrum that we see as color. 

Waves above 700 nm are infrared. We cannot see infrared light, but we feel its warmth on our skin. Waves below 400 nm are ultraviolet (UV) light waves. UV light is divided into 3 categories: UV-A (315–400 nm), UV-B (280–315 nm), and UV-C (100–280 nm). The vast majority of UV-C light is blocked by the ozone layer as it enters the atmosphere.