Two material decisions shape every pair of glasses: the frame, and the lenses inside it. This guide walks through the lens and frame materials we use at Nerdy Frames, and what each one is best for.
When you buy glasses, you’re really choosing two things: lens and frame materials. The first is the frame — what holds the lenses to your face, what determines how they feel after eight hours, what determines whether they survive a year or five. The second is the lens — what determines how thin, how light, how clear, and how durable.
Both decisions matter, and the right answer depends on your prescription, your face, and how you live with your glasses. This guide walks through each material so you understand what you’re paying for.
Acetate is plant-based, made from cotton and wood pulp. It’s the material almost every premium frame uses, and for good reason. It can be layered in sheets to create depth and tortoise patterns that injection plastic can never replicate. It’s hypoallergenic. It can be heated and reshaped by an optician, which means a good acetate frame can be adjusted to your face indefinitely.
Not all acetate is equal. Higher-grade acetate is denser, holds saturated colors more deeply, and ages more gracefully than lower-grade material. We use Japanese acetate at Nerdy Frames because the difference is visible — and because we negotiate the cost ourselves.
Injection plastic is melted, poured into a mold, and dyed on the surface. It’s cheap, mass-produced, and tends to lose color and become brittle over time. It can’t be reshaped without warping. Some big chain retailers blur the line by calling injection plastic frames “acetate-style.” They’re not.
The difference matters because acetate ages well — a good frame becomes a kept frame — and injection plastic ages badly. If you want a pair you’ll still be wearing in five years, this is one of the simpler decisions to get right.
“The cost of a real pair of frames isn’t in the materials. It’s in caring enough to specify them.”
Pure titanium is roughly half the weight of common metal frame materials like monel, doesn’t corrode, and is fully hypoallergenic when truly pure — meaning no nickel, no copper, no sensitivity. After eight hours of wear, you stop noticing a titanium frame is on your face. After eight hours in a heavy frame, you notice nothing else.
One important caveat: not every frame marketed as “titanium” is pure. The Vision Council certifies a frame as 100% titanium only when it contains at least 90% titanium and zero nickel; many “titanium” frames are alloys that may include other metals. Beta-titanium is an alloy designed to flex without taking a permanent bend, most commonly used in temples where flex matters. Memory titanium (also marketed as Flexon or Nitinol) is a nickel-titanium alloy that returns to shape after deformation — useful for kids’ frames or anyone hard on glasses, but worth knowing about if you have a nickel allergy.
Monel is a copper-nickel alloy and the most common material in mid-tier metal eyewear. It’s affordable, easy to plate, and holds shape well. The downside is that roughly one in seven adults has some degree of nickel sensitivity, and over time the plating can wear at contact points.
Stainless steel is more rigid than monel and significantly more corrosion-resistant. It’s a good choice if you want a metal frame at a fair price and you don’t have a nickel sensitivity. Neither is wrong, neither is fancy — they do the job.
Polycarbonate is the most impact-resistant common lens material — the standard for kids’ eyewear, sports, sunglasses, and any rimless or semi-rimless frame where the lens is screwed in. It’s lightweight and shatter-resistant, with a refractive index of 1.586. It also blocks 100% of UV naturally, without needing an additional coating.
Polycarbonate’s main optical drawback is a low Abbe value of about 30, which can mean some chromatic aberration at the edges of the lens. For most active wearers and for anyone who needs safety-rated optics, that trade-off is worth it. For everyday wearers without sport or rimless needs, hi-index is usually the better choice.
Hi-index 1.67 is the workhorse premium lens material. For prescriptions in the -4.00 to -7.00 range, it makes a real visible difference — your lenses are noticeably thinner, your eyes don’t appear shrunken behind the lens, and the frame sits lighter on your face. It also takes anti-glare coating beautifully, which is essential at this index because higher-index lenses naturally reflect more light.
Hi-index 1.74 is one of the thinnest lens materials commonly available. The cost premium over 1.67 is real, and the practical threshold is generally a prescription stronger than ±7.00 to ±8.00, or a thin metal or semi-rimless frame where the edge thickness of the lens is exposed and visible. Outside those conditions, the difference is often minor relative to the price.
Anti-glare coating is the one universal recommendation. It eliminates the reflections you see in your lenses, reduces eye strain at night and on screens, and makes the lens essentially disappear in photos. It’s especially important on hi-index lenses, which reflect more light than standard plastic.
Blue light filter is genuinely useful for heavy screen users — the science is debated but many people who try it report less end-of-day eye fatigue. Photochromic lenses (we use the Transitions brand) darken outdoors and are excellent if you want one pair instead of two; just be aware that standard Transitions don’t activate behind a car windshield because windshields block most UV light, while Transitions XTRActive is engineered to react to visible light and does darken moderately in the car. Polarized lenses are tinted by nature, so they belong in sunglasses. Mirror coatings, scratch-resistant coatings, and most other branded add-ons should be considered case by case rather than added by default.
Unfortunately, we don't have any direct partnerships with vision insurance providers, but we can assist you in getting a reimbursement for your purchase after you have paid in full at the time of purchase. In order to be reimbursed, you will first need to fill out a form from your insurance provider. After you fill out their reimbursement form, you will need to provide an itemized receipt, which we can provide you with once you have completed your purchase. We've provided some links below of popular vision insurance providers to help you get started.
Please contact your vision insurance for more information on how to file for a reimbursement.
If you have any question or you need an itemized receipt, please email us at info@nerdyframes.com
We accept both FSA and HSA payments, as long as they are in the form of a credit or debit card. After you have had completed a purchase with your FSA/HSA, you can then file for a reimbursement with your vision insurance provider.
