iPhone enables online buyers to measure PD

A new application for Apple's iPhone enables users to measure both their near and far pupillary distances (PD) in order to make online purchases of spectacles.

The programme's manufacturer, Sunmore Systems, tells customers that the 'easy to use' application allows them to take their own PD measurements 'with confidence', a service they are advised they will probably be charged for by an optician.

The instructions inform the user being measured to hold a bank card under their nose and take a photo. After the photo is taken, a box locks onto the strip and crosshairs appear, which the user centres in the middle of the pupil for each eye to give the PD. Sunmore claims the software, available from Apple's online iTunes store, is accurate to ±0.5mm, and that the soon-to-be-released iPad version, will be useful for the professional optometrist.