Pupillary Distance (PD) is the distance between your pupils.
This is measured from the middle of the left eye to the middle of the right eye.
You can ask a friend or relative to measure using a ruler or you can try it yourself using a washable marker pen, in front of a mirror. Dot each pupil in the mirror then measure with a ruler.
The average PD is 63. If you are unsure then please select this.