What is PD?

Your PD or 'pupillary distance' is the distance between the centre of your pupils (the black central area of each eye). As a general guide, most adult PD measurements fall between 50 and 70mm. A PD measurement is a crucial part of fitting and making your glasses and should not be overlooked.

A good optician will always take a measurement of your PD before making your glasses for you. An accurate measurement is needed to supply glasses and minimise any discomfort or distortion of vision to the wearer. We use an accurate machine to measure your PD and would not recommend accepting a PD measurement taken without the proper training and tools.

Since your eyes converge when looking at near objects, we modify the measurement if you require reading, rather than distance glasses. Sometimes an optician may specify 'monocular PD's' for your right and left eye individually. As most people's faces are not perfectly symetrical the PD measurement for one eye might be slightly higher for one eye than for the other. If this is the case we will take this into consideration when making and fitting your new glasses.

For many precriptions and particularly for varifocal and Bifocal glasses we also take other measurements to ensure the glasses lenses sit in an exact position to offer you the clarity of vision you require. This "fitting" of the frame is an essential part of making a good pair of glasses.