Effect of Classroom Illuminance on the Development and Progression of Myopia in School Children |
Young-Woo Suh, Suk-Gyu Ha, Seung-Hyun Kim |
Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea |
Correspondence:
Seung-Hyun Kim, Tel: +82-2-920-5520, Fax: +82-2-920-5520, Email: ansaneye@hanmail.net |
Received: 28 October 2021 • Revised: 15 December 2021 • Accepted: 28 December 2021 |
Abstract |
Purpose To evaluate the effect of classroom illuminance on the development and progression of myopia in elementary school children.
Methods The daylight factor, a ratio of inside and outside illuminance, was obtained in 50 elementary schools. The first-grade students in the school with the lowest daylight factor (0.51%; LD school, 145 subjects) and with the highest daylight factor (13.35%; HD school, 147 subjects) were selected. A survey was conducted to evaluate parental myopia, the amount of near-work and outdoor activities. The refractive error and axial length (AL) were measured at initial and after 6 months. The spherical equivalent (SE), AL, and the survey results were compared between the two schools. The mean AL of the emmetropic children was obtained, and all subjects were divided into two groups, more and less than mean AL. Changes in refractive errors and AL were also compared according to AL.
Result s: The amount of change in SE and AL after 6 months were not different between the 2 schools. Initial prevalence of myopia was high in the school B. However, it became similar between the 2 schools after 6 months. The mean AL of 155 emmetropic children was 22.7±0.63 mm. In the 185 children with AL ≥ 22.7 mm, there was no difference in the AL change between the two schools. However, the change in AL in 107 children with AL < 22.7 mm was significantly larger in the LD school (0.19 mm) than that in the HD school (0.15 mm) (P = 0.049). Parental myopia, near-work and outdoor activities were not different between the two schools.
Conclusion High classroom illuminance during the day reduced axial elongation in eyes of children with a shorter AL. Increase in classroom light level by permitting more sunlight can be a protective measure against the development of myopia. |
Key Words:
child health, myopia, public health, vision |
|