Evaluate the safety and effectiveness of experimental group by comparing with the control group

Compared the experimental group with the control group,the safety and effectiveness of DDM lens in mtopia control will be evaluated.

Inclusion Criteria:

• Aged 6-13,with written consent of his/her guardian,regardless of gender;
• Objective cycloplegic spherical equivalent refractive between -1.00D and 5.00D,and best corrected vision acuity of right and left eyes are better than or equal to 1.0;
• Astigmatism less than or equal to -1.50D;
• Voluntarily participate in the clinical trial and sign the informed consent.

Exclusion Criteria:

• Those with a history of ocular trauma or intraocular surgery;
• Clinical significant slit-lamp findings;
• Abnormal IOP(<10 mmHg , >21 mmHg or difference between two eyes >5mmHg);
• Patient with other eye diseases,such as uveitis and other inflammation,glaucoma,cataract,fundus disease,eye tumors,eye trauma,strabismus and any lesions that affect vision function;
• Patient with systemic diseases causing immunosuppression,such as acute or chronic sinusitis,diabetes,Down syndrome,rheumatoid arthritis,psychosis and other conditions that the investigator considers inappropriate for wearing glasses;
• Those who have participated in other drug clinical trials within 3 months;
• Only one eye meets the inclusion criteria;
• Those who cannot have regular eye examinations;
• Those who have been involved in any myopia control clinical trials,previously used or are using RGP,contact lens and glasses or atropine drugs to control myopia in the past year;
• The candidates determined by the investigator are not eligible.