The current push from the industry for Head-Mounted Display based wearable computers to the masses for everyday use suggests that academia's goals of a tight human and computer integration is achievable. Although promising, many interaction challenges remain to achieve a deep integration. Primarily that of active cognitive support in the form of focusing user attention. This thesis investigates to what degree a system can unobtrusively, perhaps even subliminally, guide attention of a user by directing their gaze from a current point to a selected point in a virtual environment. A subjective evaluation is made regarding the characteristics of visual sensory stimuli in order to possibly achieve an unobtrusive (or even subliminal) gaze guidance. The attention guidance system developed is deployed in a controlled experiment with 30 participants. Participants are asked to fire a longbow at targets in a virtual reality environment while their point of gaze is monitored with an eye-tracker. The experiment produced interesting results, but no conclusive evidence that the system was able actively guide a user's attention nor influence their choice could be observed. The conclusion of this thesis is that further development is needed towards a system that is capable of objectively calibrating the stimuli characteristics for each individual participant.