No, in that there is not a master clock, shutter, or anything like that that separates the visual input into discrete frames. Yes, in that phototransduction is

No, in that there is not a master clock, shutter, or anything like that that separates the visual input into discrete frames. Yes, in that phototransduction is a sluggish chemical process. The impulse-response functions of photoreceptors are pretty well-known (e.g, Figure 1 here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1189952/?page=5 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1189952/?page=5). The tiny square wave at the bottom is the visual stimulation; the other traces are the responses of individual photoreceptors. Figure 4 of the paper (p. 689) shows the response to a pair of flashes. In the bottom-most trace, you can see that the photoreceptor "misses" the second visual stimulus because the responses evoked by the first and second stimuli overlap in time and interfere. I'd say that the visual system does get a continuous stream of inputs, but its output is low-pass filtered (and clipped, rectified, etc) so that faster inputs are not always reflected in its output.