Text Size Affects Eye Movement during Reading among Young Adults and Adults with Presbyopia

Abstract

Objective: Reading is an activity that indirectly informs a person’s visual capacity to distinguish letters and words. Reading begins with eye movements, then substantial cognitive processing and synthesis, before becoming voice reading. Therefore, text is a factor that could impact reading quality through its control of eye movements. This study examined the eye movements of young adults and adults with presbyopia using texts of different sizes. Materials and Methods: Twenty-five young adults and twenty-two adults with presbyopia and good vision were included in this study. Six text sizes of a passage were chosen as the reading stimuli. The eye movement of participants in saccades and fixation were captured, tracked, and analyzed using the Dikablis eye tracker glasses. Results: Eye movement of young adults differed significantly (p<0.05) when reading texts of different sizes. The eyes moved more and had a wider saccadic angle as the font size increased. An increase in fixations or stopping of the eyes were observed with larger texts. Adults with presbyopia had significantly different eye movement patterns than young adults (p<0.05), whereby these participants stopped more frequently at longer periods and had a narrower saccadic angle. Conclusion: Eye movements changed when reading texts of varied sizes and the movements differed between younger and older adults. These translate to altered visual searching and attention strategies with varied text readability, indicating that the oculomotor system adapts to the pattern, shape, and size of the presented reading material. This behavior could imply that cognitive processes have been altered to facilitate comprehension.

Keywords

• Reading
• fixations
• saccadic
• presbyopia
• readers