To measure your Pupillary Distance (PD)

[Matthew Glasses]

To measure your Pupillary Distance (PD):

Place a regular ruler on the bridge of your nose. Have a friend face you about arms length away. Have your friend measure the distance between the center of your pupils (the black dots in the middle of your eyes). Or you can do it yourself simply by looking in the mirror. If you need your glasses on to do this, you can draw dots on the lenses where your pupils are (using a magic marker or highlighter); then take the glasses off and measure the distance between them.

It's simple -- like playing connect the dots!

Remember, PD number is in millimeter.

As a guideline: http://www.cheapglasses123.com/about-pd

Most adults' PD's are between 55-65. Most kids' PD's are between 42-54.