[Emphasizing the standardized use of cycloplegics in the epidemiological studies of myopia].

The prevalence of myopia in China is extraordinarily high, and much attention has been paid to the epidemiological studies related to myopia. Epidemiological investigations can be used to understand the incidence and prevalence of myopia, its epidemiological characteristics and the related risk factors. At present, there are many articlespublished in China on epidemiological surveys of myopia. However, the criteria for cycloplegic regimes are not uniform, the age limit is not definite, and cycloplegics are even not used in some researches. Lack of or insufficient cycloplegia is associated with overestimation of the prevalence of myopia and underestimation of hyperopia and leads to inaccurate assessment of risk factors. In this article, we propose standardized methods for cycloplegia in the epidemiological investigations of myopia in China by reviewing different types of cycloplegic regimes commonly used and the effects on different age groups. This will help to obtain the accurate incidence and prevalence of myopia, promote the interconnection and increase comparabilityof research data, improve the accuracy of assessing related risk factors and provide scientific evidence for the prevention and control of myopia. (Chin J Ophthalmol, 2019, 55: 561-564).