saccade

A sudden jerking movement.

A rapid jerky movement of the eye (voluntary or involuntary) from one focus to another.

He added the bill with a single saccade of his pulsing eyes.

Then 130 milliseconds or thousandths of a second later, each made a "saccade" - an extremely fast eye movement - to roughly where the ball was likely to bounce.

The act of checking a horse quickly with a single strong pull of the reins.

The sounding of two violin strings together by using a sudden strong pressure of the bow.

To make a rapid jerking movement to focus elsewhere.