Based on the theory that myopia was caused by the excessive accommodative, bifocal or multifocal spectacles for slowing the progression of myopia have been fully studied. Although some studies' results showed statistically significant for slowing myopia progression with multifocal spectacles, few had clinically meaningful, even in children with high accommodative lag or near-point esophoria. The investigators think that the possible reason for this clinical un-meaningful maybe that daily wearing bifocal or multifocal spectacles still not fully adjust the accommodative error in children.