Clinical trial to evaluate the safety and effectiveness of two kinds of ring band cylindrical lens in delaying the progression of myopia

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.

Inclusion Criteria:

1. 6-13 years old;
2. SER: -0.75 to -5.00 dioptres (D). Astigmatism and anisometropia of 1.50 D or less;
3. Monocular best corrected visual acuity (VA) of 1.0 or better;
4. Acceptance of random group allocation and the masked study design
5. Voluntarily participate in the clinical trial and sign the informed consent;

Exclusion Criteria:

1. Strabismus.
2. Ocular and systemic abnormalities.
3. Prior experience of myopia control.
4. Only one eye meets the inclusion criteria.