Frame Size Guide

Understanding Frame Measurements


If you look on the inside of your glasses, you'll find a number that looks like 50 [] 18 135. This information shows you the size of your glasses; the lens diameter, the bridge width and the side length, all measured in millimetres.


The lens diameter is the width of the lens (in mm), measured from the bridge. It can be a matter of personal choice, but it's also determined by your frame style.


The bridge width is the gap above your nose between the lenses. It's important that this is comfortable - too tight, and the glasses could pinch your nose; too loose and the glasses won't be stable on your face.


The length of the side is usually one of three standards – 135, 140 or 145mm. The side should be long enough to sit comfortably over your ears. Glasses with straight sides don't always have this measurement indicated.

Reading your frame size



Lens diameter


Lens eye size

This is the horizontal width of each lens at its widest point. It typically ranges from 40mm to 60mm.

 
frame bridge width

Bridge Width


frame bridge width number

This is the distance between your two lenses. In short, the bridge width is the space where your frames fit against your nose. The size of this piece ranges from 14mm to 24mm.

 

Side length



This is the length of the temple from each screw to its temple tip, including the bend that sits on your ear. The temple is typically 120mm to 150mm long.

 
Lens height

Lens height


This is the vertical height of your eyeglass lenses at the widest point of the lens within the frame. The lens height is important when measuring bifocals or progressive lenses.

 

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