The talk will discuss methods of probing kinetics of dark adaptation and photopigment bleaching and regeneration in rod and cone pathways, in the human eye in vivo, using the full-field electoretinogram (ERG). By delivering flashes before and after bleaching exposures, and measuring ERG amplitudes (measured at peak or at a fixed time following flash delivery) dynamics of changes in retinal sensitivity can be quantified. With several assumptions, and by taking into account response-intensity relationships in the pre-bleach dark-adapted state, these non-invasive measurements can be used powerfully to probe recovery of circulating current and photopigment in rod and cone photoreceptors, as well as the gain of phototransduction. Comparisons will be made with retinal densitometry (which provides a direct measure of photopigment levels) and psychophysical data.