깜빡깜빡

Etymology
A reduplication of.

Ideophone

 * 1)  while indeed repeatedly darkening and then brightening in quick succession
 * 2)  while indeed repeatedly brightening and then darkening in quick succession
 * 3) while indeed repeatedly blinking one's eyes
 * 4)  while repeatedly entering quite a muddled or confused state of consciousness

Usage notes
is more commonly used than the non-intensive form.