Pupillometric Assessment of the Readability of Two Video Screen Fonts

A passage of text was presented in either a normal type font or one of two unusual type fronts. While each of the 10 subjects was reading this passage, a phrase at a time, his pupil size was determined using a computer-based procedure that generated averaged response waveforms. Pupil size varied as a direct function of the cognitive load imposed by reading unusual type fonts. The average evoked waveforms showed that the pupil was consistently larger during reading in the more cognitively demanding type font.