PD Ruler, Pupillometers for Measuring Pupillary Distance, Essential Tool for Single PD or Dual PD On-line Order Eyewear

The PD ruler can help you when you want to buy glasses online.Put the notch of the PD ruler over your nose, as close to your eyes as you can, then find the middle of your pupil in a mirror, read the line closest to the middle of the pupils./br Measure pupil distance, It is a very good promotional item and perfect for hospital, pharmaceutical or medical supplies./br Measurement Range: 0-150mm./br Note that this does not come with any instructions, so if you don't know how to take a PD measurement, you will need to look that up on the internet.