"It involves engraving the surface of a standard lens with a grid of 25 near-circular structures each 2 millimetres across and containing two concentric rings. The engraved rings are just a few hundred micrometres wide and a micrometre deep."

sounds like an improved "zone plate" design.

similar optic developed for unmagnified rifle sight:

http://bulletin.accurateshooter.com/2010/05/breakthrough-microsight-technology-improves-iron-sights/