The present study aimed at examining the perceptual span, the visual field area for information extraction within a single fixation, during the reading of traditional Chinese sentences. Native traditional Chinese readers' eye-movements were recorded as they read sentences that were presented using a gaze-contingent technique, in which legible text was restricted within a window that moved in synchrony with the eyes, while characters outside the window were masked. Comparisons of the window conditions with a baseline condition in which no viewing constraint was applied showed that when the window revealed one previous character and three upcoming characters around the current fixation, reading speed and oculomotor activities reached peak performance. Compared to previous results with simplified Chinese reading, based on a similar set of materials, traditional Chinese exhibits a reduction of the perceptual span. We suggest that the visual complexity of a writing system likely influences the perceptual span during reading.