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NXT®/Trivex® Lens Core Material

Before NXT®/Trivex®

In the past, before NXT®/Trivex®, there were fragile sun lenses with excellent optical properties, or tough lenses with poor optical properties, so if choosing advanced sunglasses, the lens options were less than ideal. Therefore our research was focused on finding an enhanced lens material that solved these problems.

How NXT®/Trivex® lens technology changed everything!

NXT® was formulated in the early 1990s for the wind-shields of a new generation of battlefield helicopters.
The new material needed to be bulletproof, lightweight and optically superior.

After extensive research to optimise the technology, NXT®/Trivex® lenses became the next step in its evolution.

Learn About Why Next Generation Optical Properties Matter to You

All Bigatmo lenses are made from NXT®/Trivex® material.

We form our lenses in glass moulds with long, carefully controlled curing times. This exacting method produces lenses with very low internal stresses.
All Bigatmo lenses are made from NXT®/Trivex® material, because the result is a clear lens with advanced optical properties, you see more clearly because there’s virtually no chromatic aberration.

It’s easy to see the difference with NXT®/TrivexNXT® .

Polariscope images show internal stresses in lenses. Bigatmo NXT/Trivex® lens on the left, regular polycarbonate lens on the right.

Polariscope images show internal stresses in lenses. An NXT®/Trivex® lens is on the left, and a polycarbonate lens is on the right.

Low internal stresses are just one of the measures used to evaluate the optical quality of a lens.

Bigatmo NXT®/Trivex® lenses also have a much higher abbe number than polycarbonate. This improves the clarity of the lens, and gives you a crisp view.

Also, a refractive index that makes them ideal for both plano and RX applications.

As well as a low surface reflection which reduces glare and helps keep your eyes more comfortable.

Combined with the strength and toughness of NXT®, these elements result in a truly unbeatable lens.

Bigatmo Chromatic Aberration - NXT left, polycarbonate right

Images comparing chromatic aberration between a Bigatmo NXT®/Trivex® lens on the left, and a polycarbonate lens on the right.

More Strength and Protection Than Other Lens Materials

Let’s have a look at some of the physical characteristics of NXT®/Trivex® lenses including: impact resistance, stress cracking, UV radiation, chemical resistance and weight.

Impact Resistance

NXT® has been described as clear armour.  A sheet just 6mm thick will stop a .22 bullet.
The video shows an NXT® block stopping a 9mm round dead in its tracks:

Our lenses are less than 2mm thick and certainly aren’t bullet proof.
However, NXT®/Trivex® has by far the best impact resistance of any lens material on the market *.

It passes ANSI’s High-Velocity Impact Test

This is a stringent test where 1/4-inch steel spheres are fired at the lens at a velocity of 150 feet-per-second.

If an NXT® lens is hit, the material returns to its original shape with virtually no residual distortion.   In fact, it’s hard to see the impact point on the NXT® sample

* It’s worth noting that impact-resistant lenses cannot be classed as either shatterproof or unbreakable and that coatings may alter the impact resistance of any lens material.

Effect of impact on Bigatmo NXT® lens (left) vs. regular polycarbonate lens (right)

Effect of impact on a Bigatmo NXT®/Trivex® lens (left) vs. regular polycarbonate lens (right)

Stress Cracking

Many lens materials suffer from stress or hairline cracking over time but NXT®/Trivex® does not. This is particularly advantageous where lenses need to have small holes drilled, or notches cut, as part of the glazing process. (The result is extremely durable and long-lasting lenses).

UV Radiation

Ultra-violet (UV) radiation can have damaging short-term and long-term effects on essential parts of the eye, you may not be aware it’s happening.

Wavelengths in the ultra-violet band occur outside our visual spectrum and are all shorter than 400 nanometers.

When you choose Bigatmo sunglasses you are making the best choice to protect your eyes, you can relax and enjoy being outside, safe in the knowledge the technology is working to shield you.

NXT®/Trivex® lens material filters out harmful UV-A, UV-B (and UV-C) wavelengths naturally thereby providing 100% UV blockage up to 394nm.

This means that the lenses inherently absorb harmful UV wavelengths before even adding a sun-filter.

Chemical Resistance

NXT®/Trivex® features excellent resistance to common chemicals and solvents, such as ammonia or acetone (nail varnish remover) or even gasoline.

There is far less likelihood that innocent exposure to these chemicals will accidentally damage or destroy an otherwise perfectly good lens.

All Bigatmo lenses feature multi-coatings which might be less durable.

Lightweight Lens Material


With a specific gravity of 1.11 (g/cm³) NXT®/Trivex® is just about the lightest lens material available.

Our sunglasses are really comfortable to wear for long periods of time.  It’s easy to forget you’re wearing them.

For comparison, the most common materials used for sun lenses are Polycarbonate (sg 1.22), CR39 (sg 1.32) and crown glass (sg 2.53).

Alutra lens on the scales

Lightweight Alutra lens

Available in three different lens options

NXT®/Trivex® is the core material of all Bigatmo lenses.
There are three different lens options to suit your lifestyle.

Bigatmo Alutra lenses deliver a punchy view of the world, with excellent, vibrant colour acuity and high definition optics.

When you’re out and about the photochromic core is perfect for moving between sun and shade.
The lens tint lightens or darkens as necessary, allowing you to comfortably read instrument panels in high contrast environments, like the flight deck or when driving.

Bigatmo Zeolite lenses use advanced Light Management Technology to enhance colours by filtering out the wavelengths that fall between red, blue and green – the primary colours in which we see. Your eyes receive more specific colour information improving overall image sharpness and clarity.

Bigatmo Polarized lenses have the same colour enhancing technology as our Zeolite lenses, together with a polarizing filter which dramatically reduces glare from roads, snow, sea and sand, revealing all kinds of hidden details and textures in High Definition.