1 Scientific RepoRts | 6:28531 | DOI: 10.1038/srep28531 www.nature.com/scientificreports Chinese eye exercises and Myopia Development in school Age Children: A Nested Case-control study Meng-tian Kang 1 , shi-Ming Li 1 , Xiaoxia peng 2 , Lei Li 1 , Anran Ran 1 , Bo Meng 1 , Yunyun sun 1 , Luo-Ru Liu 3 , He Li 3 , Michel Millodot 4 & Ningli Wang 1 Chinese eye exercises have been implemented in China as an intervention for controlling children’s myopia for over 50 years. This nested case-control study investigated Chinese eye exercises and their association with myopia development in junior middle school children. Outcome measures were the onset and progression of myopia over a two-year period. Cases were defned as 1. Myopia onset (cycloplegic spherical equivalent ≤ -0.5 diopter in non-myopic children). 2. Myopia progression (myopia shift of ≥1.0 diopter in those who were myopic at baseline). Two independent investigators assessed the quality of Chinese eye exercises performance at the end of the follow-up period. Of 260 children at baseline (mean age was 12.7 ± 0.5 years), 201 were eligible for this study. There was no association between eye exercises and the risk of myopia-onset (OR = 0.73, 95%CI: 0.24–2.21), nor myopia progression (OR = 0.79, 95%CI: 0.41–1.53). The group who performed high quality exercises had a slightly lower myopia progression of 0.15 D than the children who did not perform the exercise over a period of 2 years. However, the limited sample size, low dosage and performance quality of Chinese eye exercises in children did not result in statistical signifcance and require further studies. Myopia is a major health issue in East Asia, because of its increasingly high prevalence during the past few decades, and its sight-threatening pathologies associated with high myopia 1 . Te current status of myopia in China has also raised a great deal of attention due to the young age of myopia onset and an increasing prevalence of high myopia in children 2 . As we know, young children have a progressive nature of myopia development and are sen- sitive to environmental factors 3–5 . Although myopia tends to stabilize at approximately 16 years of age 6 , children with a younger age of myopia onset are prone to becoming highly myopic at an early stage of life and may sufer from complications. Terefore, it is important to fnd simple and easy-to-use interventions, not limited to current methods of eye drops 7 or lenses 8,9 , to prevent myopia onset or to slow myopia progression in young children. Chinese eye exercises have been implemented in China as an intervention for protecting vision and preventing myopia of children since 1963 10,11 . Children in primary and junior middle schools have been required to perform eye exercises once or twice a day. When the music starts during class break, all students sit in the classroom and perform 05-min exercises along with the rhythm. Te mechanism of eye exercises is believed to be based on the theory of Traditional Chinese Medicine (TCM). By precise massage on acupuncture acupoints, Qi can be motivated in meridians and collaterals, thereby relieving eye strain and recovering eye function 12,13 . From the perspective of modern medicine, massaging on the acupoints around the eyes will accelerate blood circulation and therefore will improve metabolism, relax eye muscles and eliminate eye fatigue 14 . In spite of the long history of their popularization, the elusive efect of Chinese eye exercises on myopia has attracted increasing attention during the last decade 15 . A retrospective study reported that Chinese eye exer- cises have a modest efect on relieving near vision symptoms but no remarkable efect on reducing myopia 16 . 1 Beijing tongren eye center, Beijing tongren Hospital, Beijing Ophthalmology Visual Science Key Lab, Beijing institute of Ophthalmology, capital Medi cal University, Beijing, china. 2 Department of epidemiology and Biostatistics, School of Public Health and family Medicine, capital Medical University, Beijing, china. 3 Anyang eye Hospital, Henan Province, china. 4 School of Optometry and Vision Sciences, Cardif University, Cardif, United Kingdom. Correspondence and requests for materials should be addressed to S.-M.L. (email: lishiming81@163.com) or N.W. (email: wningli@vip.163.com) received: 04 November 2015 Accepted: 06 June 2016 Published: 22 June 2016 OPEN