Most, if not all eyeglasses include the frame measurements inside the temple arm. Frame sizes are described in three parts. The first number is the lens width, the second number the bridge width and the third number is the temple length. These numbers are in mm (millimeters).
1. Lens Width
The horizontal diameter of one lens.
2. Bridge Width
The width of the bridge section.
2. Temple Length
The length of the temple arm, from the front of the frame to the tip.
Visual Guide
| Frame Size |  |  |  |
|---|---|---|---|
| Size | Lens Width | Bridge Width | Temple Length |
| Average | 54 | 17 | 145 |