Modern eyeglasses are made from a combination of plastic or glass lenses, frames built from acetate, metal, or nylon, and smaller components like silicone nose pads and steel screws. Nearly every pair on the market today uses plastic lenses rather than actual glass, and the frame material varies widely depending on style, budget, and durability needs.
Lens Materials
Glass lenses were the original standard, but plastic has almost entirely replaced them. The most common lens material is CR-39, a plastic polymer first developed in the 1940s. It’s lightweight, produces clear optics, and costs less than alternatives. CR-39 has a refractive index of 1.499 and an Abbe value of 58, which is a measure of optical clarity. The higher that number, the less color fringing you see around objects, so CR-39 delivers some of the sharpest vision of any lens material.
Polycarbonate lenses became popular in the 1980s and are now the default choice for children’s glasses, safety eyewear, and sports frames. They’re significantly more impact-resistant than CR-39, thinner, lighter, and block ultraviolet light without needing an extra coating. The tradeoff is optical clarity: polycarbonate has an Abbe value of only 30, meaning it produces more color distortion, especially in stronger prescriptions. Most people won’t notice this, but those sensitive to visual quality sometimes do.
Trivex is a newer alternative that combines the impact resistance of polycarbonate with better optical clarity and even lighter weight. It has a low specific gravity, meaning it feels noticeably lighter on your face, and produces minimal chromatic aberration. Trivex tends to cost a bit more, but it’s a strong option if you want both durability and sharp vision.
High-index plastics (1.67 and 1.74 refractive index) are designed for stronger prescriptions. The higher the refractive index, the more the material can bend light in a thinner profile. If your prescription is above roughly +/- 4.00, high-index lenses can make a visible difference in how thick your lenses look. They do tend to have lower Abbe values, so some color fringing is possible, but lens design and coatings help minimize that.
Lens Coatings
The raw lens is only part of the picture. Most modern lenses come with several coatings layered on top. Anti-reflective coatings reduce glare from screens and oncoming headlights by using ultra-thin layers of metal oxides deposited on the lens surface. Scratch-resistant coatings add a hard shell to protect softer plastic lenses from everyday wear. UV coatings block ultraviolet radiation, though polycarbonate and Trivex already do this inherently.
Blue-light-filtering coatings have become a common add-on, designed to reduce the amount of high-energy visible light reaching your eyes from digital screens. Some lenses also receive hydrophobic and oleophobic treatments that repel water and fingerprints, making them easier to clean.
Plastic Frame Materials
The most popular frame material worldwide is cellulose acetate, often just called “acetate.” It’s a plant-derived plastic made from cotton fibers or wood pulp, mixed with a plasticizer to make it flexible. Acetate is inexpensive, lightweight, and available in virtually any color or pattern. It’s also easy for an optician to heat and adjust to fit your face. When you see bold, colorful frames at an optical shop, they’re almost certainly acetate.
Cellulose acetate propionate is a nylon-based variation that’s hypoallergenic, making it a good choice if your skin reacts to certain materials. It’s slightly softer than standard acetate. Blended nylon frames are stronger and more flexible, which is why they’re commonly used for sports and safety glasses. Nylon molds easily into wraparound shapes that stay put during activity.
Optyl is a brand-name epoxy resin that becomes extremely moldable when heated. Opticians can reshape it precisely to the contours of your face, and it returns to that custom shape even after being bent. It’s lighter than acetate and holds its fit well over time.
Bio-acetate is a newer entry aimed at sustainability. It’s derived from wood pulp and natural cotton fibers, using plant-based plasticizers instead of petroleum-based ones. Bio-acetate is biodegradable under industrial composting conditions, hypoallergenic, and durable enough for daily wear. Several eyewear brands now offer frames made entirely from bio-acetate or recycled materials.
Metal Frame Materials
Metal frames offer a thinner, more minimalist look than plastic. The most common metal used is Monel, a nickel-copper alloy that’s inexpensive and easy to shape. It’s found in a huge portion of budget and mid-range metal frames. The downside is that Monel contains nickel, which can cause skin irritation in people with nickel allergies. Most Monel frames are plated to create a barrier, but the plating can wear off over time.
Titanium is the premium metal option. It’s roughly 40% lighter than steel, highly resistant to corrosion, and hypoallergenic. Titanium frames flex without breaking and hold their shape well. Beta-titanium is a specific alloy that’s even more flexible, often used for temples and bridge pieces that need spring-like give.
Stainless steel frames sit between Monel and titanium in both price and performance. They resist corrosion better than Monel, accept color finishes well, and offer a slim profile. Aluminum frames are another lightweight option, sometimes anodized in bright colors for a modern look.
Specialty and Luxury Materials
At the high end, frames can be made from buffalo horn, wood, carbon fiber, or even precious metals. Buffalo horn frames are handcrafted, with each pair showing unique natural patterns. They’re lightweight, hypoallergenic, and warm to the touch, but they require more careful maintenance than plastic or metal. Some luxury brands combine horn with titanium or sterling silver for structural reinforcement.
Wood frames, typically bamboo, ebony, or walnut, appeal to people looking for a natural aesthetic. Carbon fiber frames borrow from aerospace engineering, delivering extreme strength at very low weight. Gold-plated or solid gold frames exist in the luxury market, though they’re rare and primarily decorative.
The Small Parts
Beyond lenses and frames, glasses contain a handful of smaller components that affect comfort. Nose pads are typically made from silicone, which is soft, flexible, and resists slipping against skin. Some frames use acetate or hard plastic nose pads instead, or have the nose bridge molded directly into the frame with no separate pad at all.
The tiny screws holding your glasses together are usually stainless steel, chosen for its strength and resistance to rust. Spring hinges, which allow the temples to flex outward without breaking, use small steel or nickel-silver mechanisms tucked inside the hinge barrel. Temple tips, the part that hooks behind your ear, are commonly made from acetate or rubber-like thermoplastic for grip and comfort.