Lenses
 

Light filtration.   
Different lighting conditions demand varying degrees of light filtration.  The European Light Filtration Standard (EN 1836:1977) divides lenses into 5 categories of filtration (FC0-FC4) based on the percentage of visual light transmitted through the lens.  Numa lenses fall into categories FC0-FC3.  Refer to the Light Filtration Chart below to see which of our lenses are right for your intended usage.

Neither light filtration level nor tint affect the level of UV protection. All Numa Tactical lenses, including Clear, provide 100% protection from all UV light.

Light Filtration Chart

Protection Filter Class (FC)

Filter 0

Filter 1

Filter 2

Filter 3

Filter 4

Description

Clear,
slightly
tinted

Light tint

Medium Tint

Dark Tint

Very dark Tint

Visible Light transmitted

81 – 100%

44- 80 %

18 – 43 %

8 – 17%

3 – 7%

Numa Lenses

Clear, Reflective Clear

Low-light Orange, Yellow Polarized, Blue Fire

Smoke

Reflector lenses

 

Recommended
usage

Dawn, twilight,
cloudy weather, protection against wind and debris

Partly cloudy skies; as blue-blocker to increase visual acuity

General use sun protection. Partly sunny to sunny days.

Beach, mountains, sunny days

Glacier hiking, high mountaineering close to the sun, conditions of extreme light radiation

UV A / -B/ -C rays blocked

100%

100%

100%

100%

100%

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