Buying glasses online may be a problem for some, but there’s
no need to worry! It’s easy to find your frame measurements
to ensure you’re getting the right fit. Inside the arm of your
eyeglasses will be three important numbers. They look
something like: 54-18-140, which reads as 54 mm lens width,
18 mm bridge width and 140 mm temple arm length.
The most important dimension— the frame width—will not be
printed. You can get the frame width by doubling the lens
width and adding the bridge width. For 54-18-140, the frame
width will be 54 mm * 2 + 18 mm, which equals 126 mm.