eog

EOG stands for electro-oculography. It is a technique for measuring the electrical potential between the front and back of the eye, produced by the cornea-retina potential. By placing electrodes on the skin around the eyes, changes in this potential are recorded as the eye moves, providing a measure of eye position and movement.

Typically, two or more surface electrodes are placed around the eyes. Horizontal eye movements produce voltage changes detected mainly by electrodes at or near the outer canthi, while vertical movements produce changes detected by electrodes above and below the eye. The recorded signal is proportional to gaze direction and amplitude. Signals are amplified and filtered to remove noise, and calibration procedures relate voltage to degrees of eye movement. Common challenges include baseline drift and variability in electrode impedance.

Applications of EOG include sleep research, where it helps identify REM sleep through characteristic eye movements; clinical neurology and ophthalmology, for assessing oculomotor function, nystagmus, and related disorders; and research and assistive technology, where EOG can be used for eye-tracking and, in combination with other signals such as EEG, in brain–computer interface workflows.

Beyond its scientific use, EOG can also refer to EOG Resources, a public oil and gas company traded on the New York Stock Exchange under the ticker symbol EOG. Context usually clarifies which meaning is intended.