The Restricted Focus Viewer (RFV) relates a small part of an otherwise blurred display to the focus of visual attention. A user controls which part of the screen is in focus by using a computer mouse. The RFV tool records these movements. Recently, some studies used the RFV to investigate the cognitive behavior of users and some others have even enhanced the tool for research of usability issues. We report on an eye-tracking study where the effects of RFV’s display blurring on the visual attention allocation of 18 novice and expert programmers were investigated. We replicated a previous RFV-based study and analyzed attention switching and fixation durations reported by an eye tracker. Our results indicate that the blurring interferes with the strategies possessed by experts and has an effect on fixation duration: however, we found that debugging performance was preserved. We discuss possible reasons and implications. Author Keywords Eye-movement tracking, visual attention, psycholog...