The process of transducing light into neuronal spikes adds significant temporal smoothing, so an image briefly flashed on the retina will be lengthened in time

The process of transducing light into neuronal spikes adds significant temporal smoothing, so an image briefly flashed on the retina will be lengthened in time somewhat before it even makes it to the brain. Need to look up exact numbers here, but this isn't all that surprising. What is quite surprising is that rod photoreceptors are sensitive to single incident photons. That's truly unbelievable.