The dimensions of each model are listed in the description/bullet points, both in mm and in inches. In general use the following guide when deciding fit. (This may not apply to sports styles which "wrap around")
Narrow (small faces) = 40-48 lens width
Medium (average) = 49-54mm lend Width
Wide (large) = 55-58mm
For RX-able Models
the "optical standard" measurement is given. This number is also inscribed on the inner temples of the glasses. There are three sets of numbers:
1. The first number listed gives the width of each of the lenses.
2. The second is the bridge, which is the distance between the lenses.
3. The third is the length of the temple arms.
Progressive glasses also take into account PD, or "pupillary distance" which is the distance between the left and right pupils. The average distance for most people is 63mm. Our progressives are set to this average. If your PD is + or - 3mm or more these glasses may not suit you. You can check your pupillary distance easily by looking in a mirror using the folding method: