Convert from cuadra [Argentina] to gnat's eye

Unit Definition (cuadra [Argentina])
In Argentina and Chile, the cuadra is equal to 150 varas (roughly 130 meters or 410 feet). Elsewhere in south and central america, the cuadra is equal to 100 varas.

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).