I begin with a sight test, then Minshull takes a topography of my eye, photographing the curvature of my cornea to obtain the measurements needed to make the lenses.

These calculations might be based on visibility (whether the tag is in the sensor's line of sight), the signal strength, or the amount of time it takes the signal to travel from the tag to the sensor.

Luggage gets opened after it is out of sight; it takes just one dishonest bag handler to put your valuables at risk.