'It's not just the frame that's important but everything that comes with it too.'

I've heard myself uttering these words a lot over the last couple of years. I think it's because I feel like this consideration is too often brushed over. This expression has kept me motivated when designing products and it still does.

Making a better (more sustainable) product for me doesn't just mean improving one material and stopping there. I believe that everything else in a product's build and lifecycle should be considered too. That's part of my design process.

MONC Founder Freddie in our London Studio.

When designing for our Conscious Collection (which will soon be our only collection) I wasn't satisfied by only changing the frame material we use to bio-acetate, I became obsessed with looking for higher quality, more conscious materials for everything in the product lifecycle too.

I decided when launching the Conscious Collection that we would only be using mineral glass lenses in our non-prescription sunglasses from now on.

What you may be surprised to hear is that glass is rarely used in sunglasses these days mainly due to their cost. Plastic lenses crept in and took over from glass when they became easier and cheaper to manufacture. We discovered that unfortunately, recycling used plastic lenses is almost impossible and our over-reliance on petroleum based plastics is taking a huge toll on our planet.



You may have some concerns as to what happens if the glass lenses crack or break from an unplanned incident. Luckily for us, technological advancements in the glass hardening process mean the risk of smashing glass lenses is extremely low. But if you’re still concerned, worry not because we are committed to replacing and recycling any lenses that fall victim to being dropped and broken*. Read on below to see our thought process and how we came to deciding what lenses we'd be using from now on.

*This is exclusively for all purchases MONC sunglasses frames with mineral glass lenses and no prescription - costs may apply.

So, WHAT's the difference FOR YOU?


In order to decide which lenses to use we went back to basics. We created a pro's and con's list for the attributes that we believe are most important when looking for the highest quality sunglasses.



Mineral glass is very hard and extremely scratch resistant. Scratching glasslenses is a very difficult and an unlikely thing to do in general day to day use.Text

Plastic lenses scratch relatively easily due to their soft surface and require a little more care in handling.

2. OPTICAL Clarity

Mineral glass offers excellent optical quality and clarity. Looking through glass presents a superior experience when comparedto plastic.

Plastic lenses offer a lesser optical quality when compared with glass, but they are also less reflective. They come in a wide variety of colours and qualities.


Glass lenses are higher in index and so can be thinner than plasticlenses. That being said glass lenses weigh a little more and are only made in small quantities and variations of size.

Plastic lenses are lighter and fit in all types and sizes of frames. They can cater for all types of prescriptions and can easily be discarded and replaced.


During this process we learnt more about our capabilities with both materials. When considering which was better we are weighing up the quality of the lens for different reasons and types of user. We're also thinking about where it's been sourced, the processes and people involved in making it ready for use in frame production. There are so many factors it's very hard to define a real winner.

Our conclusion is that it's not one or the other, but using both for the most appropriate reasons:

For Sunglasses with no prescription - we've chosen to use high strength mineral glass. It's sourced and made in Europe, and manufactured from locally sourced minerals that are less scarce or harmful to our planet when used in our product lifecycle. Its superior quality and ability to be more easily recycled made it the desirable option for us.

For Sunglasses with prescription - we've chosen to use polycarbonate plastic lenses for the time being. The reason for this is that polycarbonate plastic lenses cater for the wide variety of prescriptions and are more readily available.

When we're capable to use glass (or a better alternative) in our prescription sunglasses we will, but until we are able to order the large quantities stock required for mineral glass prescription sunglasses we are sticking to the only option we have.

Photo of a London sunset taken through two types of mineral glass lens.



As you know, we wear sunglasses to protect our eyes from the sun...if unprotected eyes are exposed to the sun, a long and intensive irradiation can lead to inflammation of the conjunctiva and cornea. In the worst case, the eye can be damaged in the long term and the lens may become cataract. Therefore, the highest regard when looking for our mineral glass sunglasses lenses was finding a manufacturer with guaranteed UV protection and the technology to ensure that every lens is to the highest specifications.

For our glass lenses, we use UV400 Category 3 optical glass, protecting against 100% UVA and UVB sun rays. UV400 is the category which blocks all light rays with wavelengths up to 400 nanometers, which covers all of UVA and UVB rays. Our sunglasses reduce visible light, which makes being outside in the sun more pleasant.



It's no secret that using too much petroleum based plastic is causing extensive harm to our environment and as we mentioned previously - it's almost impossible to recycle plastic lenses. So, when choosing the right lens, we had to find a solution that we could recycle.

Over 70% of glass's chemical makeup is sand, which combines with a mixture of other mineral compounds to become mineral glass. Glass will bio-degrade slowly, but naturally if released into our natural environment. Glass is much easier to recycle compared to plastic, which is why we believe we're doing the right thing in using it.

Thankfully, our mineral glass lens supplier champions excellence in the optical glass lens sector. They have zero waste status for their manufacturing facilities, and are among the first companies to achieve UNI EN ISO 14001 Environmental Certification.

Do it for your eyes and for the environment.