"Owain Lastname" wrote in message
...
On Tuesday, 11 May 2021 at 09:05:04 UTC+1, jon wrote:
I ordered some £30 prescription rimless reading glasses which were quite
well made, but because I could not get a 16mm nose bridge my eye pupils
were not in the centre of the 50mm wide lenses.

Glasses Direct you can put in the measurements from your existing glasses
and they will find frames that match

https://www.glassesdirect.co.uk/best...ridge_width=16

What you actually need, regardless of frame fitting, is pupillary
distance.

GD can measure your pupillary distance from a photo
https://www.glassesdirect.co.uk/pupillary-distance/

Or there are online tool things
https://www.specsavers.co.uk/glasses...llary-distance

I just used a ruler and a mirror