This paper reports the efforts to determine the reliability and limitations of the use of the electro-ocular gram (EOG) for determining the angle of eye gaze for controlling a computer. Consideration has given to determine a general mathematical expression that is subject independent and could be applied to cover all test subjects and generate the required spatial control signals. The EOG signals of five test subjects were recorded while the subjects moved their eyes to view, and then fixate on, specific target points. The target points were effectively located on the shell of a sphere of known radius. Each target point was at a known vertical angle, and known transverse angle from the orthogonal planes that dissect the test subjects eyes in the horizontal plane and the test subjects nose in the vertical plane. The experiments were repeated for determining the EOG relationship for vertical eye movement. The results obtained are encouraging. The assessment of the data suggests that EOG can be successfully utilised for spatial control applications within some limitations. The study recommends the choice of bandwidth for the recording, inter and intra subject reliability, limitation to the angle of the gaze and difference between the vertical and horizontal movement control.