A new study adds to a growing body of evidence highlighting the importance of changing the reading environment for patients with computer vision syndrome. Specifically, adjusting the lighting and reducing glare may help. And measuring a patient’s critical fusion frequency could help diagnose computer vision syndrome.

Researchers conducted a reflected glare experiment wherein participants performed a two‐hour visual task using a glossy, matte or glare‐free surface display in two visual environments (normal and glare). Additionally, subjects also took part in a visual field lighting experiment, where they performed the visual task in dim lighting, uneven supplementary lighting or uniform supplementary lighting.

Patients filled out a visual fatigue questionnaire before and after the tests, and investigators evaluated their visual function parameters, including critical fusion frequency, heterophoria, amplitude of accommodation and accommodative facility. They also analyzed visual performance and the variation of pupil size under different lighting conditions.

They found the critical fusion frequency was the only visual function parameter that decreased significantly after the visual task, and the questionnaire score was much higher in a glare environment and lower when the task was performed using a glare‐free display.

Additionally, visual performance was significantly worse in the glossy display group. The increment in the questionnaire score was smaller in the uniform supplementary lighting group, and visual performance was significantly worse in the dim lighting or uneven supplementary lighting group, but not in the uniform supplementary lighting group. Finally, investigators reported variation in pupil size was much greater in dim lighting conditions than in the supplementary lighting condition.

Lin CW, Yeh FM, Wu BW, et al. The effects of reflected glare and visual field lighting on computer vision syndrome. Clin Exp Optom. February 25, 2019. [Epub ahead of print].