The electro-oculography tracking technique is based on the fact that there exists an electrostatic field that rotates along with the eye. By recording quite small differences in the skin potential around the eye, the position of the eye can be detected; since this is done with electrodes placed on the skin around the eye, this technique does not require a clear view of the eye, which results in a large dynamic range of approximately ±70°
This technique is rather troublesome though, and is not well-suited for everyday use, since it requires the close contact of electrodes to the user. As Scott & Findlay (1993) note, this technique only satisfies requirements d, e and g.