What Are Those 3 Numbers On My Glasses?

Last Updated on May 16, 2023 by amy

Not many people give much thought to the frame size of your eyeglasses. After all, you don’t often hear people ask at the shop, “Do you have glasses in this glasses frame size with these dimensions?” Questions about the frame styles, product material, and production method are always asked. Yet as consumers’ desires for good quality glasses increases, glasses frame size plays a vital role in contributing to what is considered ”good quality.“

When you’ve worn glasses for the majority of your life, you might not take much notice of the details on your glasses. If you’re wearing them now, look at your glasses’ inside arm or bridge. What do you see? Most likely a sequence of incomprehensible numbers. Maybe a “China” or an “Italy” adorns the area, depending on where your glasses were made.

So what exactly are these numbers? You might assume they’re a product ID or model number, which would be a pretty good assumption. But no – they’re on the glasses’ frame size. However, this question remains: why do eyeglass frame sizes matter? As long as they fit pretty well and correct your bad eyesight, it’s good, right? Perhaps. But as mentioned earlier, there’s more demand for better quality and well-fitting glasses, and glasses frame size fits right into one of those crucial factors that can make or break the whole glasses experience.

Now it wouldn’t be sufficient to leave our understanding of the numbers as a general and vague concept of glasses frame size. To delve into what these numbers mean, there are usually three numbers in sequence, for example, 50-19-145.

The first number, which comprises the first part of the glasses frame size, accounts for the lens width — sometimes called the eye size. As the name suggests, lens width describes the length of the glasses lens. The lens width is usually between 40 and 60mm, excluding the frame. It’s the factor of the glasses’ frame size that can influence how well the glasses fit you. You don’t want to get glasses with an eye size disproportionate to your face.

The other two numbers in the glasses’ frame size are usually put together, separated with a dash, or sometimes by a small box between the numbers. The second number is the distance across the bridge on the glasses frame, sometimes called DBL, or the distance between lenses. The typical bridge size ranges anywhere between 14 and 24mm. And despite its seemingly minimal role in the glasses frame size, the DBL can be important because it dictates several things like how high or how low the glasses rest on the face, if the fit for the nose is too small, or the distance from the eye to the lens is too far or too close.

Perhaps what would be referred to as the “arm” of your glasses, the last number in the glasses frame size describes the temple length and is the measure of that long piece of your glasses that rests on the side of your head and behind your ear. And like the other glasses’ frame size numbers, the temple length also plays a vital role in the fit of your glasses. While manufacturers generally aim for between 120 and 150mm for the temple length, a long length will make the fit too loose, and one too short will make the fit too tight.

Now you know the three numbers are the glasses’ frame size. But maybe you’re saying to yourself, “Who cares? My glasses’ frame size doesn’t heavily impact my life. I can still go to the shop, try a pair, and buy them.” True. Simple head knowledge that the numbers compose the glasses’ frame size isn’t too helpful. We can’t argue about how glasses frame size impacts your life personally, but we can investigate why it’s still relevant.

As world trade increasingly moves to the online realm, glasses frame size plays a significant role. Anyone who shops online will understand that it’s essential to know your clothing size to make the best purchase—otherwise, there will be a lot of returns, exchanges, and shipping fees involved.

In a sense, the same applies to glasses and their frame size. In the past, when shops and companies utilized fewer online services and when ecommerce was not as big, going to an optometrist and then a shop was appropriate and completely necessary to get new glasses. But as more consumers purchase online, companies have moved more of their products and services online.

If you’re going to shop for glasses online, it’s obvious that you can’t just buy a pair of frames on a whim. Doing so would be like buying shoes without paying particular attention to the size. No, you know your shoe size and which size fits you comfortably. Likewise, frame size should fit the same role as you shop online for glasses.

Glasses are no longer strictly about utility. They’re about correcting vision, but they’re also about style, fashion, and how people express themselves. And because of this shift in the functionality of glasses, people don’t necessarily want to go through the whole process of seeing an eye doctor, getting the prescription, and then going to the shop and browsing through the millions of frames, which, not to mention, is time-consuming.

This is precisely why knowing your glasses’ frame size can save you time. And assuming that time equals money, knowing your glasses’ frame size will save you money.

A lot of conveniences come from knowing your glasses’ frame size. As mentioned earlier, you don’t have to go to the eye doctor every time you want a new pair of glasses, and you can save time going to the shop and browsing through a collection of frames that don’t appeal to you.

Glasses are specialized items and are much more specialized on a grander scale than in the past; there are a whole variety of glasses to choose from online and are not limited to just a physical shop.

Just imagine you find a beautiful pair of glasses while browsing the web. But where is this company’s shop? Amêdî, Kurdistan. Interesting. Well, you know you can’t just take a trip to get these glasses unless you are that zealous about these frames. But what’s this? They offer to ship worldwide! That certainly is good news for you. You look to the right of the screen and see a “glasses frame size chart guide” with numbers you don’t understand. As stunning as these frames are, the dark abyss of not knowing how the frames will fit hinders you from clicking that Add to Cart button.

Now that you know your glasses’ frame size, you can confidently press that same button and complete your transaction.

Good question. If you already wear glasses, you’re ahead in determining what a good glasses frame size is for you. Look at the inside of the arm of your glasses and look for those three sequential numbers we discussed earlier.

If you’ve been wearing these glasses for a while and feel that they’ve served you pretty well, then you know you have a pretty good glasses frame size to work with and one that you can use for future purchases.

With some frames, the glasses’ frame size may not be indicated anywhere on the frames. The simplest thing to do would be to take a trip to the pros at a shop to see what your glasses’ frame size is. Otherwise, you can always conduct a DIY measurement with a millimeter ruler or cloth measuring tape, but some parts may get technical.

For the bridge, you can measure horizontally at the top from the edge of one of the lenses to the end of the other. The lens width should be measured horizontally at the widest point, excluding the frame. With lens width, you need to consider your pupillary distance—something you might want to look into further should you pursue this DIY measurement.

As for the temple length, you should measure from the hinge—the point at which the arm connects to the front, where the arm begins to bend and wrap around the ear. Then you should measure the top of the bend to the bottom and add it together for a complete temple length.

Now those three numbers don’t seem so obscure, do they? Frame size is a relatively simple concept, but most people don’t pay much attention to them because they’ve never really had a reason to. However, knowing your glasses’ frame size is ultimately to your benefit. It’s not entirely necessary, but as more people opt to purchase glasses online and avoid the hassle associated with getting new glasses, it can make using and purchasing glasses more comfortable and convenient.