Simple adjustments to text contrast may offer more meaningful improvements in reading performance for patients with glaucoma than commonly recommended changes in font size or line spacing, according to a new eye-tracking study.
In research published in Scientific Reports, investigators used high-resolution eye tracking to examine how glaucoma affects reading dynamics – and whether specific visual interventions can mitigate these deficits. The study compared 57 patients with glaucoma to 54 age-matched controls, analyzing reading speed, saccades, and fixations under varying conditions of font size, line spacing, and contrast.
Reading difficulty is a well-recognized complaint among patients with glaucoma, even in those with relatively preserved central visual acuity. In this study, participants with glaucoma consistently read more slowly than controls across most conditions, reinforcing the functional impact of the disease beyond standard acuity measures.
Eye-tracking analysis provided insight into the underlying mechanisms. Compared with controls, glaucoma patients exhibited a higher number of saccades and fixations – markers of inefficient visual search and processing – particularly at lower contrast levels. These abnormalities in eye movement behavior are thought to reflect disrupted visual input and compensatory scanning strategies.
Among the three interventions tested, contrast emerged as the most influential factor. Increasing contrast significantly improved reading speed in the glaucoma group and reduced both saccade and fixation frequency across multiple test conditions. At higher contrast levels, differences between glaucoma and control participants diminished, suggesting that contrast enhancement may partially normalize reading behavior.
In contrast, modifying font size and line spacing had a more limited impact. While smaller fonts were associated with increased saccadic activity and fixation counts in glaucoma patients, enlarging text did not consistently translate into faster reading speeds. Similarly, changes in line spacing produced minimal differences in reading performance or eye movement metrics between groups.
These findings challenge some conventional assumptions about low-vision reading aids. Although larger text is often recommended, the data suggest that contrast sensitivity – frequently impaired in glaucoma – may play a more critical role in functional reading ability. Indeed, reduced contrast sensitivity in the glaucoma cohort likely contributed to the pronounced improvements observed with higher-contrast text.
Therefore, optimizing contrast – through device settings, lighting, or digital display adjustments – may act as a simple, low-cost strategy to improve reading function in patients with glaucoma.
As digital reading becomes increasingly central to daily life, such “glaucoma-friendly” design considerations, the study authors note, could play an important role in preserving independence and quality of life for people living with glaucoma.
