ETYM Old Eng. blink. Related to Blink.
A reflex that closes and opens the eyes rapidly; SYN. eye blink.

To briefly shut the eyes; SYN. wink, nictitate, nictate.
To flash on and off. Cursors, insertion points, menu choices, warning messages, and other displays on a computer screen that are intended to catch the eye are often made to blink. The rate of blinking in a graphical user interface can sometimes be controlled by the user.