UVA, UVB: beware of the sun!
UV rays
Ultraviolet rays (UV) are rays emitted by the sun. They are invisible to the naked eye and can cause sunburn without you feeling the slightest sensation of heat.
Ultraviolet rays may be divided into several types of rays: UVA, UVB and UVC rays.
- UVA rays, with the longest wavelengths, rapidly tan the skin but also cause skin ageing and wrinkles. UVA rays penetrate deeply into skin tissue and damage it.
- UVB rays, with medium wavelengths, are responsible for a gradual tan, sunburn, ageing of the skin and skin cancer. UVB rays are extremely harmful for the body but they are partly absorbed by the atmosphere.
- UVC rays, with the shortest wavelengths, are the most harmful. Luckily, these rays do not reach the surface of the Earth because they are absorbed by the atmosphere.
