When you pick up a pair of sunglasses, it is easy to see them as a simple single object, but they are actually a carefully coordinated assembly of several different components. The process of making eyewear involves a blend of industrial manufacturing and detailed assembly work. While high-end luxury brands often lean into the exclusivity of their production, the reality for most reliable and affordable sunglasses, like those found at iPOP, is a streamlined process focused on durability and effective protection. Understanding how these pieces come together gives a much better appreciation for the value they provide in the harsh New Zealand sun.
The journey of a pair of sunglasses usually begins with the frame. For most accessible eyewear, the primary material is either a high-quality plastic or a metal alloy. In the world of plastic frames, there are two main ways they are created. The first is through injection moulding, where melted plastic is forced into a precisely shaped cavity. This is an efficient way to create lightweight and flexible frames that can take on almost any shape. The second method involves cutting frames from solid sheets of acetate. Acetate is a plant-based plastic that allows for deeper colours and more complex patterns, such as the classic tortoiseshell look. These sheets are carved by machines and then tumbled in barrels of small wooden chips and polishing paste for several days to achieve a smooth, glossy finish.
Metal frames follow a different path. They are often made from Monel, nickel, or stainless steel. The process starts with a long reel of wire that is fed into a machine to be shaped into the eye wires that hold the lenses. These components are then soldered together using high heat to create the bridge and the various attachments for the arms and nose pads. Once the basic structure is formed, the frames are plated or painted to give them their final colour. This could be a classic gold or silver finish or a more modern matte black. The goal is always to create a frame that is strong enough to hold its shape but light enough to sit comfortably on the nose for hours at a time.
Why TR90 Stands Out in Eyewear Frames
TR90 glasses frames are made from a thermoplastic known as Tough Resin 90. In the world of modern eyewear, it’s a material that quietly stands out. One of the first things people notice about TR90 frames is how little they weigh.
Flexible but Built to Last
TR90 has a subtle elasticity that allows it to bend rather than snap. That flexibility gives the frames a level of resilience that suits busy, active routines. Accidental drops, a bit of twisting, or being tossed into a bag are far less likely to leave them misshapen. It’s a practical advantage that extends the lifespan of everyday eyewear.
A part of the sunglasses that often goes unnoticed until it fails is the hinge. This small mechanism is the only moving part of the eyewear and is responsible for the folding action of the arms. There are a few different types of hinges used in the industry. Standard barrel hinges are the most common, consisting of interlocking metal loops held together by a tiny screw. These are incredibly sturdy and easy to repair if the screw happens to work itself loose over time. Another popular option, especially for those who lead an active lifestyle, is the spring hinge. These have a small internal spring that allows the arms to flex outwards beyond ninety degrees. This extra "give" provides a more forgiving fit for different head sizes and helps prevent the frames from snapping if they are bent slightly during daily use.
Then we have the lenses, which are arguably the most important functional component of the entire assembly. For affordable sunglasses, lenses are typically made from polycarbonate or acrylic rather than glass. Polycarbonate is a standout material because it is incredibly impact-resistant and lightweight. It is the same material used for bulletproof glass, which makes it ideal for protecting your eyes from flying grit or accidental drops. During manufacturing, the lenses are cut from larger "blanks" to fit the specific frame shape. Before they are popped into the frames, they are treated with various coatings. The most critical of these is the UV400 filter, which ensures that the eyes are shielded from 100 percent of harmful ultraviolet rays. All of the sunglasses available have UV400 protection including our polarised frames.
Lenses can also be enhanced with different finishes depending on their intended use. For example, mirror coatings, like the Revo finishes often seen on sporty styles, are created by applying thin layers of metallic oxides to the surface of the lens. This doesn't just look good; it actually reflects a significant amount of light away from the eye, which is great for very bright conditions like a day out on the water. Other lenses might have a gradient tint, where the colour is darker at the top and lighter at the bottom. This is a practical design for driving, as it blocks the overhead sun while still allowing you to see the dashboard clearly.
While many components of a pair of sunglasses are purely functional or aesthetic, the inner core wire is the hidden "skeleton" that defines the quality and longevity of a frame. If you have ever owned a pair of plastic sunglasses that felt "springy" or eventually lost their shape, they likely lacked this internal reinforcement.
At iPOP, we incorporate inner core wire into many of our frames to ensure they stand up to the rigours of the New Zealand lifestyle. This feature is particularly prominent in our Sunpro sunglasses. By embedding a thin stainless steel rod inside the acetate or polycarbonate arms, we provide the frames with "shape memory." This means the arms won't warp in the heat of a parked car or become loose after a few months of use.
The presence of a wire core also allows for minor manual adjustments.
Once the frames are polished and the lenses are ready, the assembly process begins. This is often done by hand, especially when it comes to inserting the lenses and tightening the hinge screws. In a metal frame, a small screw in the eye wire is loosened so the lens can be tucked into a groove, then tightened back up. For plastic frames, the frames are often gently heated to make them slightly more pliable, allowing the lenses to be snapped into place. This ensures a tight fit so the lenses don't rattle or pop out unexpectedly.
The final stage of the creation process is the branding. This is where the eyewear gets its identity. Historically, in the 1960s and earlier, branding was quite subtle, often tucked away on the inside of the arms where only the wearer would see it. As fashion evolved, logos moved to more prominent locations. On sunglasses, you will typically find the brand name or logo in three key places: the outside of the temples, the top corner of the right lens, and the inside of the arms. iPOP adds their logo to the outside of the left temple.
Branding can be added in several ways. For affordable frames, pad printing is common, where a silicone pad transfers ink onto the frame. For a more durable finish, logos can be laser-engraved or even inlaid with small metal plaques. On the inside of the arms, you will also usually see a series of numbers and letters. These aren't just random; they tell you the frame measurements, the colour code, and often the filter category of the lens. This information is vital for ensuring the sunglasses meet New Zealand’s safety standards.
The concept of branding also changed how people viewed sunglasses. In the past, they were simply seen as tools for vision. Over time, they became an "affordable luxury." While a designer handbag or a high-end suit might be out of reach for many, a pair of branded sunglasses allowed people to tap into a certain style or aesthetic at a much lower price point. However, at iPOP, the focus remains on the fact that you don't need a luxury logo to get high-quality components. Whether a frame is produced by a giant fashion house or a dedicated eyewear specialist, the basic mechanics—the hinges, the UV protection, and the frame construction—remain the primary factors in how well the glasses perform.
Quality control is the final hurdle every pair must clear. This involves checking that the frames sit level, that the hinges move smoothly without being too loose, and that the lenses are free from any distortions or scratches. In New Zealand, because our sun is so intense, the UV protection levels is particularly important. A pair of sunglasses might look great, but if the components haven't been assembled correctly or the lens quality isn't up to scratch, they won't do their job.
When you look at the total process, from the raw plastic pellets or metal wire to the final polished product, it is clear that making sunglasses is a balance of chemistry, engineering, and a bit of hand-finishing. Every component, no matter how small, plays a role in the longevity of the pair. A strong hinge keeps the arms from wobbling, a well-made frame ensures they don't pinch your head, and a high-quality lens protects your sight. By focusing on these core components rather than just the brand name on the side, iPOP eyewear that is both affordable and perfectly suited to the conditions we face every day. Check all our iPOP blogs.
