Study of Dark Adaptation Phenomenon by Age and Illuminance Differences

Dark adaptation caused by rapid changes in illuminance poses potential risks. This study established illuminance conditions based on the KS A 3011 illuminance standard and Occupational Safety and Health Act to analyze the occurrence of dark adaptation and object recognition times across age groups. The experiment was conducted in an environment transitioning from bright illuminance (750, 300, 150, and 75 lx) to dark illuminance (0.5, 3, 6, and 10 lx), with participants aged between 20~29 years and 60~69 years. The participants' dark adaptation and object recognition times were measured. The results showed that participants in their 60~69 years had significantly longer dark adaptation and object recognition times than those in their 20~29 years. Specifically, under the transition from 750 lx to 0.5 lx, the average dark adaptation times were 28.17 s and 8.38 s for participants in their 60~69 years and 20~29 years, respectively. Two-way Analysis of Variance (ANOVA) revealed that both age (p < 0.05) and illuminance differences (p < 0.05) significantly affected dark adaptation and object recognition times. Additionally, setting the minimum dark illuminance to 10 lx prevents dark adaptation in most age groups, thereby reducing the risk of accidents caused by impaired vision. This study provides foundational data for improving work environments and developing safety measures tailored to aging societies.