In the present study, we recorded the eye movements of 20 criterion-based selected trainee teachers in economics while they responded to 25 single choice (SC) items in an economic content knowledge (CK) test and rated their confidence for each response in a digital assessment. By using a multilevel modeling approach with crossed random effects, we confirmed prior findings from eye-tracking research on SC tests, which showed longer dwell time on the correct response options (attractor) and shorter dwell time on the distractors are positively linked to correct options. Furthermore, we identified an additional effect on dwell time on the attractor in a moderator model with participants who highly rated their confidence for correct response options. Thus, we identified a specific role of students' confidence in their CK on the gaze bias effect. We interpret these results in terms of students' actual understanding of test contents from assessments of their professional knowledge and draw implications for further research and teacher education.