PD(pupillary distance) is very important for accurately fitting your lenses to achieve vision acuity. Generally speaking, the PD number for adults stays the same. Average PD for adults is 55-70 mm. For kids, it's about 50-70 mm. A difference of 2-3 mm is allowable.
We highly recommend checking with your doctor. You can also measure it this way.
Step 1. Stand about 25cm away from a mirror. Hold the ruler over your eyes.
Step 2. Close your right eye and use your left eye to look straight at the mirror. Keep the ruler's "0" measurement exactly in line with the center of your left pupil.
Step 3. Close your left eye and open your right eye while looking straight. And the number right directly over your right pupil is your PD.
Step 4. Repeat this a few times to make it is accurate.
1. For bifocal or progressive lenses, we strongly recommend you get this information from your optician to ensure accuracy.
2. The average PD for adults is 55-70 mm. If your DIY PD number is out of this range, be sure to confirm with your optician.