How to Choose the Correct Frame Size
How to Choose the Correct Frame Size
Many of us have seen a frame that we though would look nice on us, but the dealbreaker came when we actually tried it on. Too narrow, too wide, maybe the arms are too long or too short. Just because glasses look nice, doesn't mean they will fit nice.
Just because glasses look nice, doesn't mean they will fit nice.
If only there were an easier way... well there is! On every pair of glasses, there's numbers that will actually act as a guide as to their size. This of course, doesn't guarantee a perfect fit every time, just like having a pair of shoes that are a certain size in one brand doesn't necessarily mean another pair of shoes from a different company, but the same size won't guarantee an exact match; but it at least can act as a guide so you're not starting from scratch each time.
What the Numbers Mean
At one time or another, you've probably noticed the small numbers printed on the inside of your frame. They are usually printed on the inside of one of the arms or the bridge (the part that goes over the nose), and sometimes they are too small to see without your glasses on!
In the photo above, we are given the model number of this particular Eddie Bauer frame, "EB32009" and the "BK" in the middle stands for "Black". This is already very helpful because if I needed to replace this frame or wanted to shop around for the best price, this is number needed to find them in searches.
The next three sets of numbers, "49, 20, and 140" are our size reference. These are the numbers to look up to get an idea of the size of the frame you have, or the size to compare when shopping around.
The Horizontal Measurement
The first number, "49" means each lens is about 49 millimeters measured horizontally; like in the picture below:
I removed the lens from the frame and placed it on this ruler and you can see that it measures about 49 millimeters. I say "about" because these are actually values assigned to the frame to make organizing them easier. This lens might actually be 49.58 millimeters, but it’s easier to sort and organize frames by "49", and the other measurements are the same way.
The Bridge Measurement
The second number, "19" is what's called the "Bridge" of the frame, the part of the frame that attaches each lens to another and sits just above our nose, like a little bridge. In the photo below, you'll see that it appears to measure 20 millimeters, and I'll explain why below:
The lens isn't flush with the inside of the frame otherwise it would pop out all of the time, so the frame is grooved and the lenses are made with what's called a, "bevel" which brings the edge of the lens to a point making it fit perfectly into the groove of the frame and securely holding it in place. This adds to the size of the lens because part of the lens is actually inside the frame, so even though there appears to be a 20 millimeter space from lens to lens (measured from the closest points inside the frame), its actually about half a millimeter closer on each side. This is why it's customary for Opticians to subtract 1 millimeter from the bridge size ("DBL") when measuring frames for customers.
These first two numbers are what mostly makes us the overall width of the frame, and is referred to as the, "Frame PD".
These first two numbers are what mostly makes us the overall width of the frame, and is referred to as the, "Frame PD". In our example, we have a frame PD of 68 millimeters (49 + 19). So other frames that have a similar frame PD will have about the same width. This is also helpful when selecting frames for the first time - especially for strong prescriptions - because if there's a large difference between the frame PD and the patients' PD, the lenses will be even thicker then when they are closer together. I'll explain this more in another article, but suffice it to say to try and look for a frame with a frame PD within 10 millimeters of your own PD, especially if you have a strong prescription.
...but suffice it to say to try and look for a frame with a frame PD within 10 millimeters of your own PD, especially if you have a strong prescription.
The third number listed is what's properly referred to as the, "Temple length;" or "arm length" as most people call it. This includes the entire length of the arm from where it attaches to the front of the frame, to the end of the tip that curves around the ear (measured in millimeters also). This frame has a temple length of 140 millimeters:
It's important to note that this is the length before the arm is bent, and sometimes it can appear shorter, especially if there's a strong bend.
That's All There Is To It!
You see? That's not too difficult after all! Now you can shop mens frames and womens frames with confidence! This is a simple way to get an idea of your ideal frame. Try on a frame that's a little small? Look for one with a larger frame PD! If it fits a little too big, try one with a smaller frame PD. How about the temples that go along side your head? Too long or too short? Usually just adding 5 to 10 millimeters either way will make all the difference in the world.
What about if the frame measurements have worn off, or just can't find them? Well at least now you know how to come up with the measurements yourself - happy shopping!
Comments are welcome below!