Ever wonder what the three numbers printed on the inside of the left temple arms of your glasses mean? We'll tell you: these indicate the frame measures. Most eyewear brands print those numbers in a similar spot, so it more or less means the same thing across-the-board. See below for what they mean.
Lens width (mm) from one end to the other
Nose bridge witdth (mm) from one lens to the other
Arm length (mm) from the screw to the end of the arm
The proper fit will do wonder for your frames and face.