The effect of simultaneous dual‐focus integration on the global flash multifocal electroretinogram in the human eye

Purpose To investigate the effect of simultaneous dual‐focus (DF) on retinal activities measured by global flash multifocal electroretinogram (mfERG). Methods Thirty adults were recruited for mfERG measurement under three conditions: in‐focus (i.e., no defocus), +2.50 D DF and +7.50 D DF, administered using single vision contact lenses and DF lenses. The direct component (DC) and the induced component (IC) of the mfERG were pooled into central macular (0–8°), para‐macular (8–18°) and peri‐macular (18–30°) regions, and then compared across the three conditions using two‐way, repeated measures ANOVA. Results Simultaneous DF had a significant effect on the IC amplitude, which was significantly stronger under +7.50 D DF (p