“Blind Spot” is a type of human error. Unlike other uses of the term, in air traffic control it refers to the failure to detect a problem (conflict) right in middle of the controller’s field of view.
Currently, controller blind spot is one of the ATM top 5 operational safety priorities identified by EUROCONTROL Operational Safety Group (SAFOPS). It has been identified as an initiator in many high severity en route incidents (see the Tableau dashboard for details).