Tough-Flex™ and Lite-Flex™ Swiss Frame Materials

All Numa frames are crafted from our patented Tough-Flex™ and Lite-Flex™ materials: dependably sturdy, yet also flexible and extremely lightweight fibers. The advanced characteristics of our materials, together with our dedication to the highest level of design and quality standards, place Numa Tactical on the cutting-edge of our field. We would have it no other way, for our customers depend on our gear under the most intense conditions and in the harshest climates.

Numa Material and Design System

Numa Tactical Eyewear strives to optimize performance, functionality, comfort, and style. We have met this challenge through a combination of material and design that bring together the state of the art in both optical engineering and ergonomic principles.

Key structural details of Numa frame engineering:

  • Composed of our unique Tough-Flex™ or Lite-Flex™, patented flexible and virtually unbreakable fibers
  • Reinforced at what are typically vulnerable points: hinges and bridge of nose
  • Rubberized at point of contact with face to prevent slippage (temple and/or nose pads)
  • Vented lens design on extreme-wrap models, to allow moisture escape and prevent fogging


What do we mean by “unbreakable eyewear”?
Numa warrants that under normal wear and tear, the frames will not break. (See our Limited Lifetime Warranty for full details.)
What is “normal wear and tear”?

“Normal wear and tear” includes but is not limited to: scaling a cliff face, downhill mountain biking or skiing, parachuting, hiking rugged terrain, dropping your Numas on a hard surface, accidentally stepping or sitting on them, and even letting your toddler play with them.

UV Protection Safety Standards

Your safety is very important to us at Numa Tactical. All of our models correspond to prescribed standards and offer 100% UV protection against light wavelengths up to 400nm, blocking 100% of harmful UV rays.

Quality Control

Our in-house quality standards require that each lens that leaves our lab is free of imperfections. We are continuously performing quality inspections and it is always our goal to provide top quality at a reasonable price.


Polycarbonate is preferred over glass for active sports because it is impact-resistant, shatter-resistant, scratch-resistant, lightweight and durable.  Unlike glass, polycarbonate is flexible and bends, rather than shatters, when struck.  Numa’s lenses were tested to European ballistic standards for high-impact resistance before they were adopted by the Swiss SWAT teams as their standard issue eyewear.

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



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


Reflector lenses


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






Color Filtration

While the primary purpose of brown or grey-tinted lenses is to block all colors of light, to lessen eye-strain in harsh lighting conditions, Orange and Yellow tinted lenses have a more specific purpose.  Those lens tints make one’s vision crisper and sharper by blocking blue light, which is the cause of haze.  For this reason, these lenses are often referred to as “blue-blockers” and are the preferred tint for shooting glasses, and for dawn, twilight or cloudy-day outdoor activities.


Polarized lenses are recommended for many outdoor activities, especially fishing, kayaking, boating or any other activity where you want to eliminate the glare from a reflective surface.

Glare results from light rays hitting your eye from several directions simultaneously, as when the sun’s rays are reflected off of a body of water.  While tinted lenses block a percentage of all light from reaching the eye, polarization fulfills a more specialized function, by specifically filtering out reflected light.
When light reflects off an object it usually changes its orientation, and is therefore not in sync with the primary light source.  Polarized lenses block the reflected rays by allowing only light traveling on one plane to pass through the lens.  What reaches your eye is the light from the primary light source.  The result of this is glare elimination that does not depend on the tint of the lens: Polarized lenses can eliminate reflected glare more effectively than regular lenses without having to be as dark.  The benefits of this will be explained below.
Polarized lenses are crucial to fisherman not just because they minimize eye fatigue by reducing glare, but also because they eliminate the “mirror effect,” transforming the water’s surface from a “mirror” that reflects light into a “pane of glass” which they can look through.  This allows the fisherman to see the fish and rocks beneath the surface.  To illustrate the above point, try looking at a body of water on a bright day, or at the windshield of a car in a parking lot.  The external light source naturally causes the surface of the water or window to act as mirror.  Now put on your Numa polarized eyewear, and that mirror becomes as translucent as a pane of glass.  Now you can see the rocks and fish beneath the water’s surface, or the inside of the car in the parking lot example.

Our Low-Light Yellow Polarized lenses were designed to filter out only a small percentage of visible light while still blocking out reflected light rays, thus allowing the user to see beneath the water’s surface even in poor-light conditions (i.e.- when it is too dark to use the Smoke polarized lenses).

Lens Packages

The Tactical Lens System contains Smoke, Low-Light Orange and Clear lenses, providing you with every lens type you will need in the field.  Smoke lenses reduce eye fatigue on bright sunny days.  Low-Light Orange is ideal for dusk, dawn or cloudy days; it is a blue-blocker, eliminating haze and bringing everything into sharp, crisp focus.  Clear is suitable protection against wind, debris and UV rays on dark stormy days or for general night use.

With the Extreme Lens System, you are ready with the perfect lens for any occasion.  Set contains: Polarized Smoke, Low-Light Orange, Clear and Fire or Ice.  The polarized is ideal for high-glare conditions such as boating, fishing, driving or alpine sports.  Fire or Ice lenses are very dark for extremely bright sunny days.  Low-Light Orange is ideal for dusk, dawn or cloudy days; it is a blue-blocker, eliminating haze and bringing everything into sharp, crisp focus.  Clear is suitable protection against wind, debris and UV rays on dark stormy days or for general night use.

The Electromagnetic Spectrum

Visible light represents just a narrow bandwidth of wavelengths in the electro-magnetic spectrum.  It is bound by ultraviolet (UV) light (invisible) on the higher energy side and infrared (also invisible) on the lower energy side.  Visible light is emitted by or reflected off of the objects around us, allowing us to sense those objects with our eyes.  Our eyes are very highly evolved, sensitive instruments.  Unprotected, with a lot of outdoor exposure, our eyes can be damaged by the ultraviolet light that is emitted from the sun.  UV light can damage the cornea, retina and lens.  Numa lenses are engineered of the finest quality polycarbonate, and laboratory-tested to block 100% of ultraviolet light, protecting the eye from that exposure.

Ultraviolet (UV)0 – 380 Nm
Visible Light380 – 780 Nm
Infrared (IR)780 – 2000 Nm

Light is divided into 3 wavelength ranges:

1 Nanometer (Nm) = 10-9 meters

Visible Light

Light waves range in wavelength and frequency, but always travel at the same speed (“the speed of light”). Visible light consists of light waves falling within the wavelength range of 380 to 780 Nm (nanometers).  Within that visible range, the intensity of light can affect a person’s visual perception.  As the eye reacts to intense light, there is an immediate degradation of vision – visual acuity, depth perception and color perception decrease dramatically.  For this reason, sunglasses that filter out some light can improve an individual’s sight in strong light conditions.  This is especially noticeable on bright sunny days, out on the water, or on a snowy or icy mountain.

UV Rays

All Numa Tactical lenses (including Clear) offer 100% protection against light wavelengths up to 400nm, thereby blocking 100% of all three classes of UV rays.  UV damage is cumulative over a person’s lifetime, which means you should begin protecting your eyes and your children’s eyes as soon as possible.
Ultraviolet (UV) light is constantly emitted by the sun.   Scientists subdivide the UV spectrum into 3 categories: UVA, UVB and UVC.   UVB is recognized as the dangerous part of the spectrum while UVA and UVC are most likely harmless.   UVB rays cause sunburn and can damage the eye’s cornea, retina and lens.  Combined with cold wind and snow, UVB also has the potential to cause snow blindness (photokeratitis), a temporary (1- to 4-day) but painful problem.   Also, there is some research that suggests that daily exposure to UVB in very bright sunlight over a period of many years may cause cataracts, a gradual clouding of the lens of the eye.
UVA rays are primarily absorbed within the lens of the human eye.   There are no documented cases of UVA causing eye disorders, though this remains a much debated and researched area.  UVC rays are the highest energy and most dangerous part of the UV spectrum, but most experts agree that they are of little concern as they are absorbed by the upper atmosphere and do not reach earth’s surface.

UV Light Classes, by wavelength

UV-A315 – 380 Nm
UV-B280 – 315 Nm
UV-C< 280 Nm

Interchangeable Lenses

Instructions for changing lenses on X-Frame model:


Instructions for changing lenses on the Rider and Shark models: