Abstract Reduced time outdoors is an important factor promoting the development of myopia. The spatial frequency spectra of man-made indoor and outdoor environments, which are impoverished in high spatial frequencies (HSF), may be a contributor to human myopia development. This randomized clinical trial aimed to investigate whether HSF enhancing classroom-- outdoor scene classroom (OSC) can arrest myopia development in children. Here we showed the OSC was protective in slowing down myopic shift among children who were not myopic at baseline. The one-year change of spherical equivalent was 0.22D less among baseline hyperopic children, and 0.18D less among baseline emmetropic children in the OSC group compare to traditional classroom group. The protective effect of OSC is comparable to the time spent outdoors (Efficacy: OSC=37.1% vs. Outdoor=19.2%) and the 0.01% atropine (Efficacy: OSC=42.4% vs. 0.01% Atropine=30.9%). The study found that the OSC was protective in myopia prevention, especially in hyperopic children. Large implementation of OSC provides an alternative strategy to increased time outdoors in myopia prevention, and provides an approach that involves less disruption to school routines. Chinese Clinical Trial Registry identifier: ChiCTR2000040704.

The authors have declared no competing interest.

ChiCTR2000040704

This study was funded by the Science and Technology Innovation Program of Hunan Province, China (2023RC1079), the Ministry of Science and Techniques, China (2022YFE0124600), and the Internal funding from Guangzhou Aier Eye Hospital (GA2023001).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study adhered to the Declaration of Helsinki and had been approved by Human Subjects Ethics Committee of the Aier School of Ophthalmology, Central South University (AIER2021IRB02). The trial was registered in the Chinese Clinical Trial Registry ( https://www.chictr.org.cn; Registration Number: ChiCTR2000040704). Written informed consent were signed by both students and their guardians.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The data that support the findings of this study are not openly available due to reasons of confidentiality. Upon reasonable request, deidentified data can be accessed. Please contact corresponding author, Prof. Weizhong Lan (lanweizhong@aierchina.com).