Two-hundered and forty children aged 6-13 will be recruited and allocated to three groups. Subjects that were randomized to receive Circular cylindrical mirror modulated frame glasses (compact), Circular cylindrical mirror modulated frame glasses (strong defocus) or single vision frame glasses, respectively.~Primary outcome measure ocular axial length and the secondary indicator is spherical equivalent after cycloplegia.
Clinical trial to evaluate the safety and effectiveness of two kinds of ring band cylindrical lens in delaying the progression of myopia