Table 4.

Potential effect of blue light irradiation on refractive development, human studies

Reference, year	Species (subject)	Light sources of irradiation, exposure times	Effect of blue light irradiation
He et al., 2015 [98]	Asian school-aged children, RCT	Additional 40 min class of outdoor activities for intervention group	The cumulative incidence of myopia was lower in the intervention group (with the addition of outdoor school activities)
Wu et al., 2020 [99]	Asian school-aged children	Outdoors for 120 min every day	Continuous decrease of the prevalence of reduced visual acuity after intervention implementation in school children
Jin et al., 2015 [100]	Chinese school-aged children	Additional 20 min class outside classroom	Incidence of myopia, changes in refractive error towards myopia, change in axial length were lower in the intervention group
French et al., 2013 [101]	Australian cohort of school-aged children and adolescents, prospective study	Time spent outdoor/daylight/sun exposure	Less time spent outdoor and greater levels of near work significantly associated with incident myopia
Wand et al., 2021 [102]	Chinese school-aged children, prospective cross-sectional study	Effect of restriction of time spent in outdoor activities due to COVID-19 confinement and time and increased screen time	Prevalence of myopia was higher after the confinement than the years before
Hu et al., 2021 [103]	Chinese school-aged children, prospective study	Effect of restriction of time spent in outdoor activities due to COVID-19 confinement and increased digital learning	Incidence of myopia and axial length elongation increased after the COVID-19 confinement period
Enthoven et al., 2020 [104]	Dutch school-aged teenagers, prospective study	Computer use, outdoor exposure, reading distance	Computer use was moderately associated with myopia development The effect of combined near work was decreased by outdoor exposure
Enthoven et al., 2021 [105]	Dutch school-aged children, cross-sectional study	Smartphone use, outdoor exposure	Myopic refractive errors were higher in teenagers with episodes of 20 min of continuous use of smartphone, particularly in those with low outdoor exposure

AL axial length, CCT correlated color temperatures, DNA deoxyribonucleic acid, K kelvin, LED light emitting diodes, nm nanometer, UV ultraviolet, ROS reactive oxygen species