The pupillary distance (PD) measurement is a requirement for people who want to purchase eyeglasses. Here, find out how to measure your PD using a mirror and a ruler. Share on Pinterest Some eyewear ...

Since the scale line of a general ruler has a width, many people have had the experience of trying to draw a line of the correct length with a ruler and wondering 'how far should I draw this scale ...

All Debra Monck wanted was a tool that would help her students learn the difficult subject of measuring. Conventional rulers just didn't work, the Pohatcong Township, N.J., woman learned during her 22 ...