Twenty-three children aged 6-11 years with emmetropia, who were fitted with plano highly aspherical lenslets (HAL) defocus lenses for the first time in an ophthalmic hospital, were selected. The changes in axial length (AL) and spherical equivalent refraction (SER) before and after wearing the lenses for 6 months were observed to analyze the clinical effects on prevention and control of myopia. The results showed that after wearing the lenses for 6 months, the amount of change in SER changed from (-0.35±0.51) D to (-0.02±0.30) D, with a statistically significant difference in the rate of change in SER(P = 0.02). The amount of change in AL changed from (0.37±0.26) mm to (0.06±0.15) mm, with a highly statistically significant difference in the rate of change in AL (P < 0.001). It was demonstrated that wearing plano HAL defocus lenses had a positive effect on preventing the occurrence of myopia in children with emmetropia.