Before configuring your new lenses, it helps to know your frame’s exact measurements. It’s not required — our opticians double-check everything once your frame arrives — but knowing them helps you pick the right lens type (say, if your frame is heavily curved or oversized) and settle any questions before you order.
Good news: almost every frame already has its measurements stamped on it. You just need to know where to look.
Where to Find Your Frame’s Measurements
Open the temple arms of your glasses and look at the inside of the arm (the part that goes behind your ear) or the inside of the bridge (the section between the two lenses, over your nose). You’ll usually find a set of numbers stamped there in this format:
52 □ 18-140
Each number means something different:
Lens width (the first number — e.g. 52)
The horizontal width of the lens in millimeters, measured at its widest point. The bigger the number, the bigger the lens.
Bridge (the number between the □ symbol and the dash — e.g. 18)
The distance in millimeters between the two lenses, right where the frame rests on your nose. A narrow bridge (14-16mm) tends to sit higher on the nose; a wider bridge (20mm+) sits lower.
Temple length (the number after the dash — e.g. 140)
The full length of the temple arm, from the hinge to the tip, in millimeters. The standard measurement is usually around 135-145mm.
What If My Frame Has No Stamped Numbers?
This happens with some vintage, handmade, or very slim frames. In that case, you can measure it yourself with a ruler:
- Lens width: measure a lens from inner edge to inner edge, at its widest point.
- Bridge: measure the shortest distance between the two lenses.
- Temple: measure the full temple arm, from the hinge to the tip (including the curved part behind the ear).
You don’t need millimeter-perfect precision: a 1-2mm margin won’t affect the result. And if you’re unsure, our opticians check your frame as soon as it arrives, so any small inaccuracy gets corrected before your lenses are fitted.
Why Do These Measurements Matter for Our Process?
- Choosing the right lens type: heavily curved frames (sport, wraparound styles) need different handling than a classic flat frame.
- Anticipating whether your prescription will fit comfortably: for higher prescriptions, a frame with a large lens width may need a thinner index to avoid a bulky finish.
- Answering questions before you pay: if you’re unsure whether your frame is compatible with a particular treatment, our opticians can confirm it using these numbers, with no obligation.
Frequently Asked Questions
Do I need to know these measurements to configure my lenses?
No, it’s not required. Our configurator doesn’t ask for them to give you a quote — you only need your prescription. These measurements are useful if you have specific questions or want to check with our opticians before ordering.
What if I measure something wrong?
No problem. As soon as we receive your frame at the lab, our opticians measure it precisely before cutting your lenses. This guide is just to give you a heads-up beforehand.
My frame has no stamped numbers at all — is that an issue?
Not at all. It just means it’s a frame without visible markings (common with handmade or older pieces). You can measure it yourself with a ruler following the steps above, or simply send it to us — we’ll measure it at no extra cost.
Does the bridge measurement affect the price of my new lenses?
No. Pricing depends on the lens type, index and treatments you choose, not your frame’s measurements.