Convert from nanometer to gnat's eye

Unit Definition (nanometer)
Equal to 0.000000001 meters (formerly millimicron), or 0.03937 microinch.

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).