That’s Electrooculography!
The eye is a basically a dipole ( a separation of electric charges )
It was observed by Reymond in 1848 that the cornea of the eye is electrically positive relative to the back of the eye.This potential was surprisingly not dependent on the amount of light falling on the eye.
The cornea is the transparent front part of the eye
Dipoles and Eye Tracking
This means that as the eye moves from side to side, the dipole moves as well. To capture the movement of the dipole, one places two electrodes on both sides of the eye. ( like the one placed on this guy )
If the eye moves from the center position to the right, one of the electrodes becomes slightly positive and the other negative. This leads to a spike in the positive direction.
Source
And if the eye moves from the center position to the left, the polarity of the electrodes reverses. This leads to a spike in the negative direction.
That’s about it. That’s EOG for you all. I hope you guys enjoyed this post.
Have a great day!
Sources and Extras:
More about EOG
Gif source : The backyard brains