The Effect and Safety of Different Doses of Atropine on Myopic Progression of Highly Myopic Children: Multi-centered Randomized Clinical Trial

Inclusion Criteria: * The BCVA of distant vision is at least 0.5, near vision is at least 1.0, Titmus stereo vision is less than 80 seconds, far exotropia is less than 10 prism degrees, far esotropia is less than 6-8 prism degrees, and astigmatism is equal to or less than - 2.50 D; * Myopia progressed more than 0.5D in the past year; * Have normal thinking and language communication skills, and be able to actively cooperate with the treatment as required; * Written informed consent of guardian and child. Exclusion Criteria: * Diseases of the study eye: keratitis, keratoconus, congenital cataract, glaucoma, fundus diseases; present situation with anterior segment or posterior segment inflammation, such as acute conjunctivitis, iridocyclitis; * Systemic diseases affecting drug use: albinism, epilepsy, serious mental and neurological diseases, congenital heart disease, arrhythmia; * Atropine allergy; * Very low birth weight infants with birth weight less than 1500g; * Receiving other treatment to control the development of myopia, including anticholinergic drugs such as atropine, or participated in other functional frame lens, multifocal soft lens in the past one year; * Other situations that not suitable for participating in the trial as judged by the researcher