Measurement System (ISO8624)

 ISO 8624 specifies a measuring system for spectacle frames and related terminology. It is applicable to fronts which are intended to be symmetrical.

 - A, B, DBL, E, TL,□ 

A – Horizontal boxed lens size.

B – Vertical boxed lens size.

DBL – Distance between lenses.

E – Distance between noses.

TL – Temple length.

– Box symbol.

For example:

Printing size:  A     DBL-TL