We work alongside What-Specs to offer you the right advise relating to your Spectacle Purchase. All Specsonweb customers who have purchased glasses and do not have a Pupillary Distance measurement, a link from What-Specs will be sent to take this measurement for no extra fee. Once you select 'I do not know your PD' option, the link will be manually emailed to you. This is to ensure, that your glasses are made using the appropriate measurements.