<p>The Role of Time Exposed to Outdoor Light for Myopia Prevalence and Progression: A Literature Review</p>

Abstract

The development of myopia as a refractive disorder seems to hold multifactorial causes. Among others, increased time exposed to natural light outdoors is regarded as possible effective preventive measure against myopia development. The objective of this review is to analyse and summarize the evidence investigating the association between time outdoors and myopia prevalence and progression. Methods: A review, restricted to articles published in the last ten years, was conducted. The literature search for the included articles was performed in the following databases: PubMed, the Cochrane Library, Web of Science and Scopus. If predefined inclusion criteria were met, the studies were further categorized and data were summarized and individually evaluated. Results: Two cross-sectional studies, 7 prospective cohort studies and 3 intervention studies were reported in this review, representing the data of a total of 32,381 participants. The majority of the studies found an inverse association between myopia incidence/prevalence and increased time outdoors. The association between time outdoors and myopia progression on the other hand remains debatable; one recent randomized controlled trial indicating a protective value of increased time outdoors for further progression in myopic children. Conclusion: In summary, increasing time exposed to outdoor light seems to be a simple and effective preventive measure to decrease myopia prevalence. Also, contrasting previous review work, it may represent a potential strategy for myopia progression control. Future investigation is necessary to better define and quantify outdoor time and its effects on myopia.

Impact of COVID-19 Home Confinement in Children’s Refractive Errors

“…There is enough evidence about how children that spend more time outdoors [ 33 ] and less time doing near work activities [ 34 ] have less risk of developing myopia than those who do the opposite. The same conclusions have been found in previous studies in Spain [ 7 , 35 ].…”

IMI 2021 Reports and Digest – Reflections on the Implications for Clinical Practice

“…No interventions in decreasing nearwork have been validated in controlled trials. Strong evidence has been accumulated for time spent outdoors (principally lighting levels) decreasing the prevalence and progression of myopia, 16 – 19 possibly owing to dopamine release, decreasing the impact of other risk factors such as parental myopia 20 and higher levels of nearwork. 21 School-based intervention trials have shown that an increase in time outdoors of 40 to 80 minutes per day produces a significant decrease in the incidence of myopia.…”

“…Advising on maximizing time spent outdoors is good for all children's general mental health 35 as well as decreasing the incidence and progression of myopia, 16 – 19 especially in winter when myopic progression is greater. 36 However, as identified elsewhere in this article, this factor will have a limited effect on decreasing the incidence of myopia or its progression in those who are already myopic owing to societal factors.…”

Prevention strategies for refractive errors in users of electronic display screens: a systematic rapid review of the literature

“…Dentro de la gran mayoría de los artículos revisados, la medida de prevención que más aparecía era el incremento del tiempo al aire libre; el cual fue considerado como la mejor estrategia para la prevención y progresión de la miopía (11,19,28), no solo por su impacto en la miopía, sino que también va alineado con cambios en el estilo de vida de la población que resultan benéficos para la salud mental, cardiovascular, entre otras. En una revisión de literatura realizada en suiza (31) se halló que la mayoría de los estudios encotraron una asosiación inversa entre el tiempo al aire libre y la incidencia/prevalencia de la miopía. Esta información se puede corroborar con otros estudios, como aquel realizado en 1'060 925 estudiantes entre los 7 y 18 años de edad de 1305 escuelas primarias y secundarias en 11 distritos de ciudad de Wenzhou, provincia de Zhejiang, China (32), en donde se encontró que el tiempo que los estudiantes pasaban en línea estaba directamente relacionado con el incremento de la incidencia de la miopía (HR, 1.14; 95% CI, 1.07-1.22; P=3.39 x10-5 ) y su progresión ([SE]; B= 0.0188; P= 0.022), mientras que el tiempo al aire libre estaba asociado negativamente al incremento de la incidencia de miopía (HR, 0.91; 95% CI, 0.85-0.97; P= 0.021) y su progresión (SE; B=-0.0189; P=0.039).…”