Measure your pupillary distance (PD)
The pupillary distance is the distance between the pupil centres of the two eyes. It is usually measured in millimetres, and is important to ensure that the centre of each lens lines up with the centre of each eye when making glasses.
You can use this tool to measure your own PD (unfortunately it is not available on our mobile site at present).
Before you get started you will need:
Webcam | Any card with magnetic strip | Well-lit space