Technical information : The solar radiation 

The solar spectrum consists of three wavelength families:

Ultraviolet rays or UV from 100 to 380 nanometers 

They are not perceptible by the eye. They are nevertheless the most harmful and are divided into 3 types:    

• UVA (315 to 380 Nm) are the principal cause of the eye ageing
• UVB (280 to 315 Nm), harmful, they are at the origin of sunburn
• UVC (100 to 280 Nm), are the most dangerous for the eye. They are luckily filtered through the ozone layer.

“UV400” appellation guarantees a 100 % protection against these radiations. However, the proportion of UV increases according to the solar intensity radiation. Altitude, light and reflection play a crucial role in choosing the appropriate lens.

The visible light from 380 to 780 nanometers 

It corresponds to different eye visible colours and breaks down as following: 

• 380 - 500 Nm: purple-blue
• 500 - 600 Nm: green-yellow
• 600 - 780 Nm: orange-red

Infra-reds between 780 and 2000 nanometers 

Imperceptible, they are responsible for a warming and drying phenomenon. Although not very dangerous, they can cause some damage to the eye, following a too intense sun exposure