Their use could cause a delay in counting votes because they cannot be read by optical scanners.

WSJ: Sandy Prompts Shifts in Voting Procedures

Gov. Crist said he wants to get rid of all those touch-screen machines and replace them with optical scanning systems that would read paper ballots.

NPR: Florida Move Would Back Up Electronic Voting

Scout now pulls your vitals in ten seconds using just optical sensors, which enables it to read the vital signs of others -- as opposed to the prototype which utilized an EEG sensor and could only record the info of the person holding it.

ENGADGET

Nano bar codes are the molecular versions of traditional bar codes--metal nano-particles that have specific, recognizable chemical fingerprints that can be read by a machine, perhaps a UV lamp or optical microscope.

FORBES: Safer And Guilt-Free Nano Foods

The team is already thinking of applications for metamaterials as read-heads for future generations of hard-disk drives or optical modulators for communications.

ECONOMIST: MONITOR