<div class="_help_font_site selected-art-author"> <p><strong>What is PD?</strong></p> <p>PD stands for Pupillary Distance, which is the distance between your pupils in millimeters. PD is very important for accurately fitting your lenses to achieve visual acuity.</p> <p>Generally, PD numbers do not change for adults. The average PD range for adults is 55-75 mm and for kids is about 42-55 mm. A difference of 2-3 mm is acceptable.</p> <p>&nbsp;</p> <p><strong>How to measure PD?</strong></p> <p><iframe height="315" src="https://www.youtube.com/embed/KpcN94kf5j0" width="500"></iframe></p> <p>We highly recommend checking your PD with your doctor, especially for bifocal or progressive lenses.&nbsp;</p> <p>You can also measure the PD by yourself.</p> <p><strong>Download a printable PD ruler and check how to measure the PD <a href="https://www.firmoo.com/images/PD%20Ruler.pdf">HERE</a>.&nbsp;</strong></p> <p>&nbsp;</p> <p><strong>How to read PD?</strong></p> <div id="intact_31"> <p>Your PD may be written in three ways:<br /> 1. PD (OU), written as &quot;64&quot;, means the Binocular PD which is for both eyes.</p> <p><img alt="" src="https://df5apg8r0m634.cloudfront.net/images/2019/0322/fBdfyaqAZu.jpg" /></p> <p>2. PD (OD), means the Monocular PD for the right eye. PD (OS), means the Monocular PD for the left eye.<br /> A Monocular PD is written as two numbers, for example, &quot;32/32&quot;, the first one &quot;32&quot; represents the PD for the right eye, and the second one &quot;32&quot; represents the PD for the left eye.&nbsp;</p> <p><img alt="" src="https://df5apg8r0m634.cloudfront.net/images/2019/0322/iHqmaWSh5P.jpg" /></p> <p>3. Sometimes PD is written as &quot;62/59&quot; or they are labeled &quot;Far&quot; and &quot;Near&quot;. Your PD is usually measured for distance vision, which is &#39;Far PD&quot;, or &quot;62&quot; in this example. For reading glasses, doctors measure your &quot;Near PD&quot; or &quot;59&quot; in the example.<br /> Always enter your &quot;Far PD&quot; for distance vision eyeglasses and enter your &#39;Near PD&quot; for your reading glasses only. For most people, the difference between Far PD and Near PD is about 2-3mm.</p> </div> </div>
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