Convert from quarter to gnat's eye

Unit Definition (quarter)
The quarter is an informal unit of distance equal to 1/4 mile, 2 furlongs, or 402.336 meters. This unit is used in athletics and horse racing.

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).