A Guide to Frame Measurements
On your existing pair of eyeglasses you may have noticed certain numbers on the arm. These indicate the dimensions of your eyeglasses frame and are commonly visible on eyeglass frames.
The numbers of interest to us in the example above are 49 – 21 – 140
49 (mm) is the Lens Diameter
21 (mm) is the Bridge Width
140 (mm) is the Arm Length
Understanding Frame Measurements
Frames generally have five different sizing measurements. In addition to the three mentioned already there are another two.
Frame Width – which is the width of the glasses across the face and is used to indicate whether frames are Narrow, Medium or Wide
Narrow - Narrow (Small) Frame – Frame Width < 119mm
Medium - Medium Frame – Frame Width is between 120mm and 125mm
Wide - Wide (Large) Frame – Frame Width is over 125mm
However it's only an indication so if the PD Range corresponds to your measured PD and the TRY ON frame tool looks good then you should be ok.
The other measurement Frame Depth is used to determine whether a frame is deep enough to be able to mount a bifocal or a progressive lens.
Frame Depth > 28mm then the frame is suitable for bifocal and progressive lenses
Frame Depth <= 28mm then the frame is only suitable for single vision lenses.
Choosing a Frame
If you're happy with your existing frames then choosing another pair with similar dimensions (eg +/- 2mm per measurement - it doesn't need to be exact) should ensure a good fit for your new frames.
By selecting the following filters on the shopby menu on the right hand side:
you only get the frames displayed which match those search criteria.