How to Measure Your Pupillary Distance

Measuring pupillary distance (PD) is easier than some opticians might lead you to believe.

The dark middle part of your eye is called the pupil. The number of millimeters between those points on your eyes is a measurement you need to order glasses online. More people than ever before are enjoying the dollars they save by using the internet to purchase glasses. Armed with the prescription from your annual exam at the optician, the PD is usually the only other number you need to place an order online.

Here are simple instructions on how to measure your own pupillary distance at home.

1. Put on a pair of glasses and looking at your eyes in the mirror, mark a dot at the center of each pupil with a non-permanent marker.
2. Take off your glasses and with your ruler, measure the number of millimeters between the two dots.
3. That's all there is to it. Simple, wasn't it?
4. If you measured inches, you can convert to millimeters by multiplying inches times 25.4. As an
5. Find a millimeter ruler (PD is always given in millimeters). If you don't have one, measure with inches and convert to millimeters.
6. example, 2 1/2 inches times 25.4 equals 64 millimeters. You can also Google for a conversion calculator from inches to millimeters to make it even easier.

To know if your PD is in the ballpark, here are the usual numbers: 55-65 is the range for most adults and 42-54 for children.

If you are unsure of doing it yourself, you can have a friend help you.

1. Simply put a ruler on the nose.
2. With your friend at a distance of a couple feet get the distance between your pupils.

Using these easy instructions, you can determine your own pupillary distance at home and save money on on your next glasses purchase.