The effect of central and peripheral luminance on visual acuity.

Context: Lighting conditions significantly influence visual acuity (VA), visual function, and quality of life. Previous research highlighted a correlation between luminance and VA but left a gap in understanding the impact of surrounding luminance. This study focused on investigating the effects of both central and peripheral luminance on VA.

Purpose: This study aimed to investigate the influence of both central and surrounding luminance on VA through distance VA measurements.

Settings And Design: A dual-component lighting system was utilized, comprising a self-illuminated ETDRS chart and a skyLED system for consistent surrounding illumination. Two experimental setups were conducted: the first varied the central luminance (25 ± 2-341 ± 10 cd/m²), while the second maintained a constant central luminance (150 ± 5 cd/m²) and varied the surrounding luminance (4 ± 2 cd/m² OFF-105 ± 10 cd/m² ON).

Methods: Sixty-six participants with refractive errors between 0.0 D and -2.75 D were tested under various lighting conditions. Both uncorrected refractive error (URE) and corrected refractive error (CRE) eyes were evaluated.

Statistical Analysis Used: Paired t-tests were used to evaluate the statistical significance of differences in VA scores.

Results: Experiment 1 demonstrated a significant increase in VA scores, with mean improvements of -0.120 LogMAR for URE eyes and -0.073 LogMAR for CRE eyes as chart luminance increased from 26 cd/m² to 153 cd/m². Experiment 2 further showed a notable improvement in VA scores under varied surrounding luminance conditions, with mean improvements of - 0.118 LogMAR for URE eyes and -0.073 LogMAR for CRE eyes as luminance increased from 4 cd/m² to 102 cd/m².

Conclusions: This study emphasizes the significant impact of both central and peripheral luminance on VA. The introduction of the skyLED lighting system underlines the importance of optimal lighting for visual performance.