Evolving Iron Sights

The Firearm Blog has a post about a new iron sight idea. The new system used a lens and "zone plates" and allows the user to focus on both the front sight and target at the same time.

It looks like an interested idea with certain applications for target shooting. I don't think I'd put such a device on my defensive firearms simply because if you break the lens I imagine the sighting system would be useless. But this thing looks cool regardless.