We wear sunglasses to protect our eyes from sunlight and not to have to use our hand as a shield.
The darker the lenses, the higher the protection.
The levels of protection are divided up into so-called filter categories.
The EU categories, which are usually indicated in five digits, Roman (I to V) or Arabic (0 to 4), are helpful here:
|Filter category||Weather conditions||Glass shade||Utilization|
|0||3 – 20%||It offers the least protection. Colorless or very light filter. Typically sport or protective glasses designed to protect against wind, dust or debris, but not against the sun.|
|1||20 – 57%||For partly cloudy days. Very lightly colored lenses, usually yellow or orange, suitable for weaker sun radiation or as wind or dust protection.|
|2||57 – 82%||Suitable for normal summer days. A medium-dark filter is suitable for medium sun radiation and casual wear. The tint is slightly lighter than usual. It can be used for spring and autumn walks on sunny days. They also come in handy while driving and frequently moving between shade and sun.|
|3||82 – 92%||It offers intensive protection. Recommended for holidays by the sea, in Southern Europe, and for mountain walks. Dark filter suitable for intensive sun radiation on the beach or in the city. This category is typical for most types of sunglasses. It is perfect for summer because it provides a higher degree of protection against sun radiation than the previous category.|
|4||92 – 97%||Particularly strong protection, which is suitable for high mountains and glaciers. Category 4 sunglasses are forbidden in road traffic. These are marked with the symbol of a crossed-out car. Very dark filter for very intensive sun radiation. Sunglasses for mountains or desserts and everywhere where the sunshine is not just extremely strong, but where it also reflects a lot.|
As good as the quality of the lenses is, up to 60% of the UV rays can penetrate from above or through the sides.
Therefore, large lenses and a wide temple can contribute to optimal protection. In addition, wearing a hat or cap can be helpful.