in the twinkling of an eye
In an instant, as in The breakup of Yugoslavia created many warring nations in the twinkling of an eye. This hyperbolic expression, which alludes to the very brief time it takes for an eye to blink, is heard less often today. [c. 1300]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.