- A common three-number marking is written as lens width – bridge width – temple length.
- Lens width is the horizontal boxed dimension of one lens; bridge width describes the distance between lenses under the selected measuring system.
- Temple length is measured along the side from its reference point to the end.
- The sum of two lens widths and the bridge is not necessarily the full outside frame width because endpieces can add width.
- Use the dimensions to compare frames, not to guarantee visual appearance or comfort.
Reference basis
This page describes a measurement procedure. It does not certify the fit of a specific product.