Pupillary Distance
Pupillary distance (PD) is the distance between the pupils of your two eyes. It is an essential measurement when buying a new pair of eyeglasses or prescription sunglasses.
Without a correct measurement, the prescription power of your lenses will be off-center from your eyes and you won’t be able to see out of your glasses, even if your prescription is otherwise 100% correct. 100% correct.
How to Measure Your Pupillary Distance (PD)
1
Stand about 30cm away from a mirror, Looking at yourself, hold a ruler up against your eyebrows.
2
Close your right eye, then line up the ruler so that 0mm is in line with the middle your left pupil.
3
Look straight ahead again and then open your right eye and close your left.
4
Your pupillary distance measurement will be the figure that lines up with the centre of your right pupil.
PD measurement: Alternate method
1
Wearing your glasses, stand in front of a mirror (about 12 inches away) and close your right eye
2
Using just your left eye, put a small mark on the left lens of your glasses, directly in front of your pupil.
3
Without moving your head, close your left eye and open your right eye.
4
Using just your right eye, put a small mark on the right lens of your glasses, directly in front of that pupil.