Since 1995, European legislation guarantees their filtering capacity. You must therefore always choose CE marked sunglasses followed by a number from 0 to 4 indicating the degree of protection.
CE2 glasses are suitable to the country’s mention EC3 offers good protection but not enough for the high mountains, the sea, the Deep South or the tropics, EC4 that require protection and an infrared filter.
Degree of Protection (European Classification):
|Categories||Indication||Degree of protection|
|Class 0: Clear or very lightly tinted glass.
These are generally glasses “aesthetic comfort.” This filtration category is very light and does not effectively protect itself from ultraviolet radiation when exposed to strong sunlight.
|Indoor / scattered clouds||0 to 20%|
|Class 1: Slightly tinted glass.
This type of sunscreen is recommended for reduced sunlight situations, such as in winter or very gray time. This index is not recommended for massive exposure to strong sun rays.
|Solar luminosity attenuated||20-57%|
|Class 2: Medium tinted glass.
This sunscreen is effective in medium sunshine situations.
Class 3: Dark glass.
This sunscreen is effective in situations of high solar luminosity: the sea, the beach, or for winter sports.
The index 3 blocks 100% of UV.
|Strong solar luminosity||82 to 92%|
|Class 4: very dark glass.
This sunscreen is indicated in cases of extreme solar luminosity eg for climbing on glaciers or in the high mountains as the brightness is increased tenfold by the reflection on the ice and snow.
The index 4 protection is prohibited for driving because you will do nothing if you go through a tunnel.
|Exceptional solar luminosity / not to wear to drive||Over 92%|
Normally, the presence of the sun, the iris decreases the size of the pupil which has the effect of naturally protect our eyes from sun damage. Although the amount of light reaching the retina is reduced, natural filter is not enough for sunglasses. These are UV that are responsible for the burning of the eyes. UV come from all sides of the eye, left right but also above or below, you must choose which of glasses covering the eye.
Panoramic models or with side shields prevent UV from reaching the eyes through the sides, but they sometimes lead to the distortion.
The solar filter index of protection class sunglasses thus corresponding to the filtration capacity of the sun, it must be chosen according to your situation.