The effect of font width on eye movements during reading.

Certain font features (e.g., letter width) can change the amount of space occupied by text in published works. Font styles/features are also known to affect reading eye movements (EM); however, few studies have examined these effects - and none used high-resolution displays. We examined the effects of font width on EMs by utilizing four fonts, from the Univers family, which varied in letter-width magnitude. Participants' (n = 25) reading speed, saccade velocity, and the duration/number of fixations and saccades were recorded. The Ultra Condensed font significantly influenced readability and yielded: fewer fixations and saccades; longer fixation durations than the Roman and Extended fonts; and shorter saccade durations, relative to the other fonts. Readers efficiently adjusted their EMs such that no reading-speed differences were observed. The eye-tracking metrics revealed two trade-off effects: (1) fewer and shorter EMs and (2) more and longer EMs, which were revealed by the font-width manipulation.