Effect of Correlated Color Temperature of Organic Light-Emitting Diode Lighting on Near Work-Induced Transient Myopia and Accommodation Lag during Reading

Abstract

Abstract – Introduction: Correlated color temperature (CCT) is a commonly used index to quantify the spectral composition (wavelength) of light. Animal experiments have shown that compared with high-CCT lighting (4, 000 and 5, 000 K), low-CCT lighting (2, 700 and 3, 000 K) slowed the axial growth of young rhesus monkeys. Meanwhile, studies have affirmed the effectiveness of repeated low-level red light for myopia control in children and adolescents. This study aimed to evaluate the effect of different CCTs of organic light-emitting diode lighting on accommodative lag (LAG) and near work-induced transient myopia (NITM), providing a preliminary foundation in this field. Methods: The refractions of 31 young adults (11 males) were measured with an open-field autorefractor at 33 cm after 30 and 60 min of reading under 4, 274 K and 1, 877 K. The initial NITM and LAG were assessed objectively at baseline and every 30 min. The use of two CCTs was determined in the order of the random number table. Results: After reading under 30 min, the mean LAG for low-CCT lighting was slightly lower than the high-CCT lighting (−0.97 ± 0.53 D vs. −1.21 ± 0.50 D, p = 0.10); after reading for 60 min, the difference was significant (−1.09 ± 0.55 D vs. −1.36 ± 0.51 D, p = 0.048). When grouped according to the degree of myopia, both mild myopes (−1.11 ± 0.43 vs. −1.38 ± 0.60 after 30-min reading, p = 0.38; −1.34 ± 0.27 vs. −1.5 ± 0.54 after 60-min reading, p = 0.53) and moderate myopes (−0.90 ± 0.57 vs. −1.12 ± 0.42 after 30-min reading, p = 0.16; −0.96 ± 0.61 vs. −1.28 ± 0.50 after 60-min reading, p = 0.05) presented lower LAG magnitude under low-CCT lighting than high-CCT lighting, while the difference was not significant. As for NITM, no significant difference has been found between two CCTs in any group. Conclusion: Reading under low-CCT lighting (1, 877 K) had a lower LAG magnitude than reading under high-CCT lighting (4, 274 K), suggesting the potential usefulness of low-CCT lighting for reducing LAG magnitude during near work.