Convert from vershok to gnat's eye

Unit Definition (vershok)
Obsolete Russian weights and measures were used in Imperial Russia and after the Russian Revolution until they were replaced in the Soviet Union by a metric system in 1924.

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).