The Ashbury Griffin sunglasses are a legit pair of shades that feature Carl Zeiss CR-39 lenses, and in case you aren't into camera or optical lenses, just know that Carl is the king of optics.
These measurements include the width of the lens, the width of the bridge, and the length of the arms measured in millimeters.
For example, a 56-17-144 frame:
1) Lens Width - 56mm
2) Bridge Width - 17mm
3) Arm Length - 144mm