Children aged 7-14 years with high myopia were randomly assigned to a control group or an intervention group at a 1:1 ratio. The intervention group wore H.A.L.T. MAX lenses for at least 10 hours per day for 2 years, and the control group wore ordinary single-vision (SV) spectacles for at least 10 hours per day. At the 1-year follow-up examination (6-month visit), control subjects whose equivalent spherical diopter change (SER) was ≥0.75 D were switched to H.A.L.T. MAX lenses until the end of year 2. After entering year 2, all remaining control (SV) subjects will be replaced with H.A.L.T. MAX defofocus frames for at least 10 hours per day until the end of year 2. And continue to wear it for at least 10 hours per day. To evaluate the efficacy, safety and compliance of H.A.L.T. MAX lenses in delaying myopia progression in children with high myopia, and to provide a scientific basis for the formulation and practice of public health programs for delaying myopia progression and the risk of blindness and visual impairment caused by high myopia.

In a 2-year randomized controlled study, the intervention group wear H.A.L.T. MAX spectacle lenses for more than 10 hours a day for 2 years. During the first year, the control group wore conventional single-vision (SV) spectacles for at least 10 hours per day. At the 6-month follow-up visit, if the spherical equivalent refraction (SER) change in the control group (SV) participants was ≥0.75 D, they were switched to H.A.L.T. MAX spectacle lenses until the end of the second year. In the second year, all remaining control group (SV) participants were transitioned to H.A.L.T. MAX defocus spectacle lenses and continued wearing them until the study concluded. To evaluate the efficacy, safety and compliance of H.A.L.T. MAX lenses for delaying myopia in children with high myopia, and to provide a scientific basis for the development of prevention strategies for children with high myopia.

Inclusion Criteria:

• Voluntary, willing to follow the protocol, able to read and understand the information form and give free and informed consent (for parents/guardian of children subjects) and assent (for subjects aged 7-14 years old);
• 7-14 years old，regardless of sex;
• Spherical equivalent refraction (SE) after cyclopegia ≤ -5.00 D and ≥ -9.00D;
• Anisometropia and Astigmatism ≤2.50D;
• Best corrected distance visual acuity of at least 0.8 in both eyes;
• Willing to wear only the spectacles provided by the investigator for all days (>10 hours) during the study without additional interventions;
• Accept randomization;
• Able to sign the informed consent form with the accompaniment and understanding of parents or guardians.

Exclusion Criteria:

• Allergic or intolerant to cycloplegic drugs；
• Exclude children on high dose atropine (1%) or red light therapy；
• Any previous history of myopia control treatment in the previous 30 days, like low dose atropine, defocus spectacles, or thokeratology and acupuncture；
• History or presence of an ocular disease, strabismus or amblyopia or other binocular vision abnormalities, accommodation dysfunction, and cataract.；
• History of eye surgery；
• Ocular or systemic diseases that may be associated with myopia, such as Marfan syndrome, retinopathy of newborns, diabetes, etc；
• Anatomic or skin factors affecting the wearing of spectacles；
• Other conditions unsuitable for inclusion (patients with excessive expectations for the effect of the defocus spectacle lenses or desires to try other myopia interventions).