Tag Archives | pd ruler

How to Measure Your Pupillary Distance

Do you know your PD? For glasses wearers, knowing your pupillary distance (or PD) is very important. Your PD is the distance between the center of each pupil and it serves an important purpose. With a correct PD, you can ensure that your lenses will be correctly positioned in their frame. At 39DollarGlasses.com we offer [...]

Read full story Comments { 0 }