- How it Works
May 24, 2019
Your pupillary distance, also known as PD, refers to the distance between your pupils, measured in millimeters (mm). It’s important to know how to measure pupillary distance if you want to order eyeglasses online. The eyeglasses manufacturer use this number to make the best-fitting lenses for you to see as clearly as possible.
Normally, measuring pupillary distance does not take place during a typical eye exam. If you plan to purchase eyeglasses after the exam, you will get measured for pupillary distance. This is along with vertex, wrap, and pantoscopic tilt, all of which affect the position of your eyeglasses.
There are several methodologies that may be used to take this measurement, including the use of a tool called a pupillometer, through photographic analysis, or even with a regular ruler.
You can measure your pupillary distance at home through one of two options:
Ruler: As we mentioned before, you can use a ruler as many opticians use in their office. Just be sure your ruler can offer measurements in millimeters (mm), as this is the standard unit of measurement eyeglass retailers use. If you don’t own a ruler with millimeters, the retailer you wish to use to purchase your eyeglasses most likely offers a printable ruler on their website. Set your printer to print the actual size of the page, instead of using a “fit to page” or another setting, and this will work just as well.
If you use a ruler, be sure to get the help of a friend or family member when you measure pupillary distance, because they will be able to get a more accurate reading than you can in the mirror by yourself. It’s extremely important to have an accurate PD measurement because this dictates how your eyeglasses manufacturer will position the lenses.
Some people mark their eyeglasses and measure the two dots on their lenses with a ruler to find their PD.
EyeQue PDCheck: You can use EyeQue’s PDCheck to capture your PD instantly by taking a picture or selfie. The patented frames and pupillary measure app are accurate and fast! You can store results in your free EyeQue membership account and retake your PD in case your PD changes.
With the VisionCheck you can test your vision from home and use the results to order glasses online. Updating your glasses has never been easier!Buy Now