Measuring the pupillary distance or PD

The pupillary distance (PD) is the distance between the centers of the pupils of the eyes, measured in millimeters. It is different for each person.

The best option is to see a specialist who can measure it. However, if you do not have this option, you can choose one of the following possibilities to measure the pupillary distance.

1. How do you measure the pupillary distance on your own?

  • Firstly, you will need a ruler.
  • Look at the mirror, which should be on a distance of 20 cm. You will see the mirror image of the numbers on the ruler.
  • Hold the ruler at eye level. Imagine, you are looking into the infinity. This way, eyes will not move inwards.
  • Direct your nose straight to the mirror. Close your left eye to avoid mistakes.
  • Set number 0 straight at the center of the right pupil, which is a black spot in the middle of an eye.
  • Now close the right eye and open the left one without moving the ruler.
  • Carefully read the number in the center of the left pupil. The face must be flushed with the mirror.
  • Repeat the procedure a few times to confirm measured values.

2. How does someone else measure your pupillary distance?

  • Firstly, you will need a ruler.
  • The best way to do this accurately is to sit straight looking at each other. The distance between both persons should be 45 cm or the length of a stretched arm.
  • The person who is having PD measured (patient) must have both eyes open and always look at the open eye of the person, who is measuring.
  • This person should cover alternately left, and right eye since eyes of both persons must be in the straight line when reading the value.
  • The ruler must be aligned at the center of the pupil of one eye while reading the value at the other eye.
  • Repeat the procedure two or three times to confirm measured values.

3. You can use our ruler for the measurement of the pupillary distance.

  • Here you can find our ruler, which you can print out, but be careful to choose the »actual size« before printing.
  • Cut out the ruler and fold it in half.
  • Check again if the ruler is printed in its actual size. You can do this by comparing it to the actual ruler. You can also compare the marked empty space on the paper to your bank card – they should be the same size.
  • Repeat the procedure as written in 1st and 2nd item.