Table 5 Eligibility Criteria.

1. Ages from 6 to 12 years at the start of the study

2. Cycloplegic autorefraction (spherical equivalent) from −4.50 to −1.50 D in both eyes

3. Astigmatism (cycloplegic autorefraction) ≤ 1.50 D in both eyes

4. Anisometropia (cycloplegic autorefraction) ≤ 1.50 D

5. Best-corrected visual acuity ≥ 0.00 logMAR units in both eyes (equivalent to Snellen 20/20)

6. No strabismus or other ocular diseases except refractive error

7. No systemic diseases that might affect refractive development

8. No use of medications that might affect refractive development

9. No history of wearing bifocal or progressive addition spectacles

10. No history of orthokeratology or use of contact lenses