Effect of different font sizes and of spaces between words on eye movement performance: An eye tracker study in dyslexic and non-dyslexic children

The aim of the present study was to explore the possible change in eye movement performance in a group of dyslexic and non-dyslexic children reading four lines of a text with different font sizes and spaces between the words. Fifteen dyslexic children from 7 to 12 years old and two groups of fifteen non-dyslexic children, respectively reading and chronological age-matched group, participated in this study. Horizontal eye movements from both eyes were recorded by a video-system (EyeBrain T2 (R)) while the children were reading a text. Three different texts were used with different font sizes and spaces between words. Results showed that increasing font size and character spacing significantly reduced duration of the fixation and increased the number and amplitude of prosaccades in all groups of children tested. Interestingly, while reading texts in which the letters were larger and more spaced (Texts 2 and 3), the duration of fixations in dyslexic and in non-dyslexic children groups decreased, becoming similar to those reported in the non-dyslexic children group. We suggest that large letter spacing between words could be employed in schools to help dyslexic children in order to ameliorate their reading performance.