Different types of lenses
Granite eyewear is available with several different types of lenses. All of them block ultraviolet UVA and UVB rays. The material used in most of our lenses is shatterproof acrylic, but we also use unbreakable polycarbonate for some special purpose frames, particularly for use in sports activities. The most common types of lenses can be used in the following instances:
Yellow, orange, and amber lens
Gives better contrast in poor light, e.g. dusk, fog, and snowfall; a perfect lens for skiing, bicycling, and shooting. This lens is also suitable for driving in low visibility conditions.
Normal tinted lens
This lens (known as normal sunglass lens) reduces sunlight considerably and gives real color recognition. Available in grey, green, and brown.
Absorbs horizontal reflexes and glare from water surfaces, wet roads, and snow. Suitable for driving, skiing, or sailing. Mirror & flash lens A normal tinted lens, with a tinted reflective coating on the outside (mirror effect). Reduces sunlight, snow and water glare considerably. Several shades are available, but silver is the most common. The flash lens has a slight mirror effect, not as pronounced as an actual mirror lens.
Granite sunglasses comply with European standards: EN ISO 12312-1:2013. For technical documentation EU declaration of conformity please follow the link to https://www.fostergrant.co.uk/ppe The sunglasses are categorized according to different filters, depending on how much visible light is filtered (how dark the lens is). The table below indicates at which light strength a certain category of lens is suitable.
- Filter category 0 Dull
- Filter category 1 Weak sunlight
- Filter category 2 Average sunlight
- Filter category 3 Strong sunlight
- Filter category 4 Exceptionally strong sunlight (Not suitable for driving)
The frame item number and the lens filter category number are printed along the inside of the bow. This makes it easy to choose a frame for a specific need.