1
general::
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]
American Heritage Idioms
2
general::
Phrase(s): in the twinkling of an eye [and] in the wink of an eye
Fig. very quickly. • In the twinkling of an eye, the deer had disappeared into the forest. • I gave Bill ten dollars and, in the twinkling of an eye, he spent it.
McGrawhill's American Idioms And Phrasal Verbs