Eye-tracking study finds Bionic Reading changes gaze but not reading speed

Bionic Reading bolds parts of words to guide the eyes, but an eye-tracking experiment with 90 skilled adult readers found it altered where people looked on longer words without speeding them up. The University College London researchers tested bolding at the beginnings versus middles of short and long words. The findings appear in Royal Society Open Science and question whether the method improves reading efficiency.

The study involved 90 proficient adult readers, ages 18–40, with no reported reading disorders or neurological/neurodevelopmental conditions. They read 90 single-screen sentences in Courier New under three formats: no bolding, initial-letter bolding, or middle-letter bolding on target words. After each sentence, they answered a true/false question. Eye tracking measured first fixation location, total viewing time including revisits, and word skipping. Target items were common four- and eight-letter words, such as “doll” and “princess.”

An earlier 2025 eye-tracking paper in Attention, Perception, & Psychophysics reportedly found that bolding word beginnings slowed reading. The new University College London experiment instead separated two claims: whether bolding redirects gaze and whether it improves processing. It found initial bolding moved first looks toward the start of eight-letter words, but neither beginning nor middle bolding shortened reading times. Comprehension was near ceiling, around 95% correct, leaving little measurable benefit.

Count: first paragraph ~70? Let's count. "The study involved 90 proficient adult readers, ages 18–40, with no reported reading disorders or neurological/neurodevelopmental conditions. They read 90 single-screen sentences in Courier New under three formats: no bolding, initial-letter bolding, or middle-letter bolding on target words. After each sentence, they answered a true/false question. Eye tracking measured first fixation location,