At present a number of studies have attempted to embed eye-tracking devices into closed-loop systems to augment the cognitive state of the human operator. It has been demonstrated that the pupil diameter and blinking frequency serve as such indicators. Although these two factors serve cognitive state analysis , other measures are required that explain the relation of objects in the world (e.g. tracks) and the operator's understanding of the state of these objects, specifically applied in an operational setting like command and control. Stated differently, the measurement of a number of these factors over time provide a performance indicator that explains how well the operator is capable of following the dynamics of the environment, which on its turn serves as a cognitive state assessment and as a measure of situation awareness. Next, this paper reports on a number of practical considerations and solutions on the usage of the eye tracking devices installed on a novel multi-monitor combat management workstation. Each eye-tracker suffers a certain measurement error but this error behaves non-linear due to its multi-monitor setup and its related large viewing range. Over time, this error becomes dynamic due to drifting issues. Both problems are addressed in a compensatory algorithm by combining explicit input (i.e. a mouse click) with eye-tracking data given the fact that motor control movement is initiated and guided by perception.