Bloc Billy Bloc Billy Brown Tortoiseshell
Bloc Billy Bloc Billy Brown Tortoiseshell
Bloc Billy Bloc Brown Graduated Cat 3 Lens

Bloc Billy

£35.00

Classic unisex shape for all uses. The distortion free, impact resistant XTR Karbon8 optical class one Category 3 lenses provide maximum protection against UVA, UVB and other harmful blue light up to 400nm.

Stock Codes and Packed Weights

Bloc Billy

Brown Tortoisehell
£35.00
3 In Stock

Classic unisex shape for all uses. The distortion free, impact resistant XTR Karbon8 optical class one Category 3 lenses provide maximum protection against UVA, UVB and other harmful blue light up to 400nm.

  • Category 3 18-8% light transmission.
  • Heavily tinted on a graduated brown base for general purpose to bright light conditions.
  • Silicon hypoallergenic non-slip nose pads.
  • XTR Karbon8 Lens.
  • MTX and Karbon TX injected temples.
  • Suitable for driving.
  • Sized for medium to large heads.

Tested to BS EN ISO 12312-1:201.

Category        Usage
0 Not really a category - transmits 100% of visible light. Protection against grit and ice only. 
1 43% - 80% visible light transmitted. Suitable for use in cloudy conditions with virtually no direct sunlight eg blizzards and whiteouts 
2 18% - 43% visible light transmitted. Suitable for use as general sunglasses and in cloudy conditions in the mountains, but not in direct sunlight in mountain areas where there will be a lot of reflection off snow and ice.
3 8% - 18% visible light transmitted. Suitable for Alpine and Himalayan mountaineering for most uses, but for prolonged exposure at high altitude Category 4 is recommended.
4 3% - 8% visible light transmitted. For prolonged exposure at high altitude and especially if you have weak eyes. Will be found too dark for everyday use and should not be used for driving a car.

*Categories 3 and 4 are the only categories suitable for Alpine and Greater Ranges mountaineering - however, just because the lenses are suitable does not mean that the design of the glasses is.

We have placed cookies on your device to help make this website better.

Your order contains no items