In The Twinkling Of An Eye Meaning

(idiomatic) Immediately; instantaneously.

Example: circa 1598, William Shakespeare, "The Merchant Of Venice":
  I'll take my leave of the Jew in the twinkling of an eye.
2007 April 28, Hugh Muir, The Guardian:
  All my dreams for him have been cut short in the twinkling of an eye. Why was my son murdered?