The present study explores the relationship between eye movement behaviour and control ability in the context of cognitive workload. The role of eye movement behaviour of radar controllers in the control process was analysed in the light of the actual work of the controllers. It is posited that controllers primarily utilise eye gaze and scanning behaviours to obtain flight information and monitor the flight operation situation in the sector, thereby ensuring the safety of the aircraft. The thesis thus undertakes a comparative and analytical investigation of the gaze and scanning behaviours exhibited by level 3, 4 and 5 controllers, with a view to ascertaining the disparities in their control abilities. Additionally, it explores the influence of accumulated workload on controllers’ control ability, by comparing the gaze and scanning behaviours of controllers of the same level before and after posting.