Light-adapted (LA) electroretinograms (ERGs) from 90 individuals with autism spectrum disorder (ASD), mean age (13.0 ± 4.2), were compared to 87 control subjects, mean age (13.8 ± 4.8). LA-ERGs were produced by a random series of nine different Troland based, full-field flash strengths and the ISCEV standard flash at 2/s on a 30 cd m[superscript -2] white background. A random effects mixed model analysis showed the ASD group had smaller b- and a-wave amplitudes at high flash strengths (p < 0.001) and slower b-wave peak times (p < 0.001). Photopic hill models showed the peaks of the component Gaussian (p = 0.035) and logistic functions (p = 0.014) differed significantly between groups. Retinal neurophysiology assessed by LA-ERG provides insight into neural development in ASD.