Tiffany

LENS HEIGHT 

The maximum height of the lens size in the frame which is measured from the tip to the bottom of the lens aperture of the frame. This measurement is especially important for bifocal lenses or progressive lenses.

BRIDGE WIDTH

Bridge width is the gap above your nose between the lenses. It is the shortest distance between the lenses, typically ranges from 14mm to 24mm. If you have a narrow bridge or your eyes are a close set, you will want this number lower (15mm to 18mm) and if you have a wider bridge or a wide set eyes, you will like to have a higher number (18mm to 22mm).