This study was aimed to evaluate the effects of different Orthokeratology，including the size of central optical zone and the height of peripheral reverse curve, on myopia control and visual quality.

This study was aimed to evaluate the effects of different Orthokeratology on myopia control and visual quality. The different optical zone of Orthokeratology lens was divided into 4 groups, ranged from 5.5 mm to 6 mm. And the control group subjects with the single glasses was included. The effectiveness of Orthokeratology was measured by axial length progression. The visual quality of subjects was evaluated by a questionnaire, contrast sensitivity and wavefront aberration.

Inclusion Criteria:

• Myopia: between -1.00D and 4.00D in both eyes
• Astigmatism: <1.5D for with-the-rule astigmatism, <1.00D for the against-the-rule astigmatism
• Visual acuity: the best corrected vision acuity(BCVA)≥20/20 in both eyes
• Subjects that volunteer to participate in the clinical trial and sign informed consent

Exclusion Criteria:

• Contraindications of wearing Ortho-K.
• Diagnosis of strabismus, amblyopia and other refractive development of the eye or systemic diseases.
• Any type of strabismus or amblyopia
• Systemic condition which might affect refractive development (for example, Down syndrome, Marfan's syndrome)
• Ocular conditions which might affect the refractive error (for example, cataract, ptosis)