Your PD, or pupillary distance, is important when ordering your glasses online, as it is the distance between your pupils, measured in millimetres.
This measurement is important to help us deliver the clearest possible vision in your new glasses.
Your PD is usually written as one value ( e.g. 64) but can be written as 32/32 if your eyes are a equal distance from the bridge of your nose, or written 31/34, if one eye is slightly further away than the other.
Average PD measurements for women are 62 with men at 64.