What it looks like
The cornea is positive relative to the retina. With a blink the globe rolls up (Bell's phenomenon), bringing that positivity to Fp1 and Fp2: a large, symmetric, frontopolar deflection that falls off steeply behind the forehead. 11
What it means at the bedside
In a comatose patient, rhythmic "blinks" can be nystagmus or eyelid myoclonia during a seizure. Look at the eyes and the video.