April 7, 2022 OPTOMETRY TIMES ARTICLE Alex Delaney-Gesing, Senior Editor Sunlight in the classroom can be a protective measure against the development of myopia, researchers have found.
Investigators from the Korea University College of Medicine studying classroom daytime illuminance found that the level of light can be a factor in the deveolopment of myopia in children. Investigators in South Korea evaluating classroom illuminance during the day found that increasing light levels by allowing more sunlight can be a protective measure against the development of myopia. Young-Woo Suh, OD, Suk-Gyu Ha, OD, and Seung-Hyun Kim, OD, from the Department of Ophthalmology at the Korea University College of Medicine in Seoul, Korea, examined the daylight factor—the ratio of inside and outside light in 50 elementary schools, according to the study, which was published in the Korean Journal of Ophthalmology. Researchers selected 145 students in the first grade of the school with the lowest daylight factor (0.51%) and 147 students in the first grade of the school with the highest daylight factor (13.35%). A survey was then conducted among participants to evaluate three factors: parental myopia, the amount of close-up work, and outdoor activities. Investigators measured the axial length (AL) and refractive error at initial and after 6 months. Survey results, spherical equivalent (SE), an AL were compared between the 2 schools, according to the study. The mean AL of the emmetropic children was also obtained, and all subjects were placed into two groups: more and less than mean AL. Additionally, the changes in refractive errors and AL were also compared according to AL. Findings Investigators report that there was no change in the amount of SE and AL between the 2 schools following 6 months of observation. While there was a high initial prevalence of myopia in the first school, it became similar to that of the second school’s amount after 6 months. In total, the mean AL of 155 emmetropic children was 22.7±0.63 mm, while 185 children with AL ≥ 22.7 mm showed no difference in the AL change between the 2 schools, the study found. However, investigators stated that the change in AL in 107 children with AL < 22.7 mm was significantly larger in the lowest daylight factor school (0.19 mm) than that in the school with the highest daylight factor (0.15 mm) (P = 0.049). Additionally, parental myopia, near-work, and outdoor activities were not different between the two schools, the study found. Investigators concluded that high classroom illuminance during the daytime reduced axial elongation in children with a shorter AL in their eyes. Additionally, they stated that allowing more sunlight into the classroom can be a protective measure against myopia development.