Convert from bicron to gnat's eye

Unit Definition (bicron)
The Bicron is an obsolete metric unit of distance, which was defined as 10e-12 meter or 10e-6 micron. This distance is now called a picometer or picometre (pm). The name is a reference to the double prefix "micro-micron".

Unit Definition (gnat's eye)
The gnat's eye is an idiomatic "unit" of distance; it's common to hear that something is "as small as a gnat's eye". In fact, the eyes of typical gnats tend to have diameters similar in size to a hair's breadth: roughly 100-150 micrometers (0.10-0.15 millimeters).