Accurate Pupillary Distance Measurement: Why Does It Matter?

Your doctor might measure your pupillary distance (PD) during your eye exam. This measurement refers to the distance between your eyes. If not measured right, you could end up with the wrong prescription, resulting in discomfort, eye strain and headaches. 

Keep reading to learn why having an accurate pupillary distance measurement matters. 

How Do Eye Doctors Measure Pupillary Distance?

Only trained eye care professionals can perform pupillary distance measurements. They might use a pupillometer, digital PD meter or special ruler to measure your PD. PD is measured in millimeters, and even the littlest error can lead to several eye problems and vision issues.

Your optometrist uses PD to determine the ideal size of glasses for you. They might use it as a reference to assess your vision and eye function. However, it doesn’t usually impact your vision correction, which is why you won’t find it in your eye prescription. 

Why Does It Matter?

You’ll see clearly and comfortably if the lenses of your glasses sit directly in front of your pupil. The middle of the lens is the clearest part of your prescription. Besides seeing clearly, lining the center of the lenses with your pupil reduces the likelihood of eye strain. 

PD says a lot about your depth perception. Eye doctors use it to learn more about your stereo acuity. Each of your eyes receives different images, but your brain combines them to create a three-dimensional image. With PD, eye care professionals can further understand vision differences between the left and right eyes. 

Whether you need new eyeglasses or contact lenses, Northern Virginia Doctors of Optometry is more than happy to help. We have friendly doctors and staff who will ensure your comfort during your visit. Call us at (703) 413-1400 (Crystal City) or (703) 522-7676 (Clarendon). You may also fill out our online form to schedule an appointment.