Despite the global use of atropine in myopia control, the mechanism by which atropine acts to inhibit the progression of myopia is still unclear. This study investigates the effect of atropine on the human global flash mfERG under conditions of retinal defocus. Our results imply that atropine acts in the peripheral retina to enhance mfERG responses in areas of the retina experiencing myopic defocus. These findings suggest that atropine may potentiate the effects of myopic defocus in inhibiting axial eye growth and myopia.