Understanding sunglass lens materials
Sunglass lenses can look similar from the outside while being made from very different materials.
The material affects optical clarity, weight, impact resistance, thickness, coating compatibility and how the lens performs over time. It is separate from other features such as colour, UV protection and polarisation.
There is no single material that is best for every application. Each involves a different balance of qualities.
CR-39
CR-39 is an optical resin widely used in quality eyewear. It is valued for clear, natural vision and a comfortable weight. Compared with glass, it is lighter and less likely to shatter, while still providing strong optical performance.
CR-39 also accepts tints and surface treatments well, making it suitable for a wide range of sunglass lenses.
Its main limitation is that it does not offer the same level of impact resistance as polycarbonate or some nylon lenses. For everyday sunglasses, however, it provides a well-balanced combination of clarity, comfort and finish.
This is the material used across current VANDA sunglasses.
Nylon
Nylon lenses are lightweight, durable and particularly well suited to curved or wraparound frame designs.
The material can be formed into complex lens shapes while maintaining good visual performance. It also offers strong impact resistance, which makes it useful for sport, performance and active eyewear.
Nylon can be more expensive to produce than some common lens materials, depending on its construction, coatings and optical requirements.
Its flexibility and durability make it highly capable, although those advantages may be unnecessary for a flatter everyday frame.
Polycarbonate
Polycarbonate is known for being lightweight and highly impact resistant.
It is commonly used in safety glasses, sports eyewear and situations where protection against impact is a priority. It can also be made thinner than some other materials.
The trade-off is that its optical performance can differ from CR-39 and glass, particularly toward the edges of larger or more strongly curved lenses. Surface coatings are also important because untreated polycarbonate can scratch relatively easily.
It remains an excellent material when impact resistance matters most.
Glass
Glass has traditionally been valued for its clarity and strong resistance to surface scratching.
It can provide an exceptionally crisp view, but it is heavier than the other common lens materials and can break under impact. That added weight is particularly noticeable in larger sunglass frames or during extended wear.
For these reasons, glass is now less common in everyday lifestyle sunglasses, although it remains an option for brands and customers who prioritise its particular optical qualities.
The material is only the foundation
Lens material does not determine everything about a pair of sunglasses.
A finished lens may also include UV protection, visible-light tint, polarisation, scratch-resistant treatment, anti-reflective treatment, hydrophobic and oleophobic coatings. Each performs a different function.
For example, a CR-39 lens can be polarised or non-polarised. A polycarbonate lens can be dark without necessarily being polarised. UV protection depends on the completed lens specification, not simply the base material.
Which material is best? The right material depends on how the sunglasses are intended to be used.
- CR-39: well suited to clear, comfortable everyday eyewear
- Nylon: useful for curved, active and performance-focused designs
- Polycarbonate: ideal where lightweight impact resistance is the priority
- Glass: suited to those who value its clarity and scratch resistance and accept the additional weight.
Rather than asking which material is universally best, it is more useful to ask which qualities matter most for the frame and its intended environment.
Why VANDA uses CR-39
VANDA uses CR-39 because it provides the balance we want for everyday sunglasses: optical clarity, comfortable weight and reliable performance.
Our current frames are not highly wrapped sports designs, nor are they intended to function as safety eyewear. They are designed for daily use, driving, travel and time outdoors.
The material forms the optical foundation, while UV400 protection, Category 3 tinting and selected surface treatments complete the lens specification.
