Continuous visual perception and the dark adaptation of vertebrate photoreceptors after
bright light exposure require recycling of their visual chromophore through a series of
reactions in the retinal pigmented epithelium (RPE visual cycle). Light-driven chromophore
consumption by photoreceptors is greater in daytime vs. nighttime, suggesting that
correspondingly higher activity of the visual cycle may be required. However, as rod
photoreceptors are saturated in bright light, the continuous turnover of their chromophore by …