If you want to know what size you need, the easiest way is to look at the three numbers that are usually engraved on the temple, such as 52-18-140. Those numbers indicate the width of the glass, the bridge and how long the temple is, but be careful, you can also measure your face and the distance between pupils if you want a perfect fit.
Why it matters so much to choose the right size of eyeglasses
Choosing the right frame is not just about looking good, the truth is that it affects the health of your eyes and your daily routine. When glasses are not the right size, the center of the lens does not align well with the pupil, and that's where eyestrain, dizziness or constant headaches appear.
And then there's the issue of comfort. A frame that is too tight will bother your temples and nose, leaving red marks and irritating your skin. But if they're too big, they'll slip all the time and you'll have to pull them up every so often, which is annoying and distracting. That's why, before you start shopping, it is essential to make sure you know the size of the glasses and see how to know which glasses fit your face so you don't have these problems.
And if you already know you want an iconic model, it's best to take a look at the right Ray-Ban eyewear sizes to fit your face perfectly.
How to understand the measurements of the glasses you already have
To know your size quickly, the easiest way is to look at the glasses you already wear, of course, as long as they are comfortable and do not slip. Most brands put the technical measurements on the inside of a temple, although sometimes they also appear on the bridge.
These numbers are in millimeters and follow a standard format worldwide. No matter the brand, the sequence always reads the same, so you can compare models without having to physically try them all on.
What do the three numbers on the pin mean?
The first number (52): is basically the width of the crystal, which is what they call the caliber.
The second number (18) is the size of the bridge, which is nothing more than the distance between the two crystals.
The third number (140): is the length of the entire rod, from the hinge to where it rests behind the ear.
Caliber, bridge and rod length: what do they really mean?
So that you don't make the wrong choice, it's good to understand these concepts a little better:
The Caliper: is the horizontal measurement of the lens at its widest part. It is the most important data to know if the glasses are "small", "medium" or "large", because if you fail here, your eyes may be too centered or too far out of the glass. Also, if you have a prominent nose, take a look at these guidelines on how to choose glasses for big noses, so the bridge won't bother you.
The Length of the Rod: This is what makes the glasses stay fixed on the head without disturbing. If they are too short, they will not go around the ear well, and if they are too long, they will be too long at the back and the glasses will be moving all the time.
Step by step: How to measure your face to buy eyeglasses online
Sometimes it's a bit scary to buy glasses online, but if you follow a few easy steps you won't go wrong. If you are looking for the perfect style, we recommend you to consult tips to get your glasses right. You only need a millimeter ruler or a tape measure, although if you have a mirror at hand, much better.
Before we start, I recommend you take a look at our guide to choosing glasses according to your face, because it's not all about the size, it's about making sure the design fits your face. For example, if you're looking for shades that highlight your light hair or you prefer the trendy rimless glasses trend, style is key.
The total width is basically the width from temple to temple. To measure it properly, place the ruler horizontally just above the eyebrows, cross it from one side of the face to the other and note how much it measures in millimeters.
How to measure interpupillary distance (IPD) without failure
The interpupillary distance is basically the space between the center of one pupil and the other. This is key, especially if you need prescription lenses, as it centers the power of the glass right where you need to look.
If you dare to measure it yourself at home, do this:
Stand in front of the mirror and stand up straight.
Rest a millimeter ruler right on the bridge of the nose.
Close the right eye and place the zero of the ruler right in the center of the left pupil.
Now, without moving the ruler, close the left eye and open the right eye, see what measure marks the center of the right pupil and write it down.
If you want to switch to multifocal lenses, you can take a look at these steps to get progressive glasses and do it correctly. Also, before making any changes, I recommend that you get an eye exam to see if you need glasses and check that everything is okay with your vision.
How do you know if your glasses fit you well? The golden rules
Beyond the numbers, there are some aesthetic and functional guidelines that tell you if a frame suits you. It's no use if the size is right if the glasses don't look natural on your face, in the end it's a matter of harmony.
To balance size with style, the ideal is to look at how the volumes of the face are distributed.
Where should the eyes be in the glass?
It is best if the eye is centered horizontally on the lens. If you notice that it is very close to the bridge, the glasses are probably too big, but if it goes too far out, the frame is small. On the vertical part, the eye has to be in the upper half, so you avoid the eyebrow disappearing or being too high.
How they should fit on the nose and temples
If the bridge is well adjusted, the glasses rest smoothly and do not leave ugly marks on your skin. If you feel that the bridge "bites" your nose, you need a wider size. At the temples, the temples should not press too much; they should not squeeze your head until it hurts, but they should not be so loose that the glasses move every time you turn your head.
Take advantage now to take a look at the trends in modern frames, because they mix comfort with modern designs very well.
How to prevent eyelashes from rubbing against the frame
Many people forget to look at the depth of the frame when choosing a size. If you see your eyelashes rubbing against the glass or the rim when you blink, chances are the frame is too deep for your face or the angle is off. It's a hassle, and it also soils the glass fast, so you end up seeing worse; if this happens, remember to follow a guide to clean your glasses properly.
How frame material and type of frame influence
Depending on the material of the glasses, the sensation when wearing them changes a lot, and it also influences whether they can be adjusted afterwards. Remember that, in addition to the frame, it is essential to know which shade of glass suits you best to improve your vision.
Metal frames: They usually weigh less and, best of all, they are adjustable. You can adapt the bridge to your nose with the nose pads, and the temples can be bent a bit so they don't bother your ear. If you're looking for something lightweight and durable, go for these; for example, there are solid reasons to choose titanium glasses because they hold up well and don't cause allergies.
Paste (Acetate) frames: These are more rigid and do not move as much. Therefore, the size has to be perfect from the first moment, since there is almost no margin for retouching anything. And well, if you want something more discreet, open frames look very elegant and are super minimalist.
Tips for daily care and maintenance
If you want to see well and your glasses to last much longer, you need to take good care of them. In addition to regular cleaning, you can follow these basic steps:
First, wash your hands thoroughly before touching them, so you don't transfer grease and dirt to the glass.
Use warm water to rinse them, this serves to remove the dust that sometimes makes scratches if you rub directly.
Put a drop of neutral soap on them and carefully rub both sides of the lenses.
To dry them, use a clean, microfiber cloth for glasses, not paper or scratchy cloths.
Common doubts about spectacle sizes
Here are the answers to the most common questions we get asked when measuring and choosing a frame. If you don't know which size to choose between two options, keep in mind that a lot depends on the material:
In metal: I'd say go a little bigger. Since they can be adjusted, the optician can reduce the width without hassle, but trying to enlarge a frame that is too small for you is simply impossible.
In paste: here it is the shape of your face that rules. If you have a wide face, go for the larger size, but if it is narrow, choose the smaller size so that they don't slip all the time.
Does my face shape influence the size I have to choose?
Of course. The technical size is the starting point, but the shape is what makes everything fit well. For example, if you have a round face, rectangular frames tend to suit you better because they give more structure, and if it's square, oval frames help soften your features. It is also key to look at the nose, because if it is more prominent you need a wide bridge so that the glasses are not too high.
How can I tell if an eyeglass is too big or too small?
There are several signs that tell you this:
Too big: If you tilt your head a little and the glasses slip, or if you notice that your eyes are too close to the bridge, it is not your size. It also happens if the temples do not grip the ear well.
Too small: You notice quickly if they squeeze your temples, leave red marks on your nose or if the bottom rim touches your cheekbones every time you smile.
How do I know if the model I buy is authentic?
When you're looking for premium brands, it's normal to be concerned about authenticity, especially if you're shopping online. There are some basic safety details you can check; for example, take a look at these tips to find out if your Prada glasses are genuine and avoid imitations.
