# What is the max amount of photons per second of the rods and cones in our eyes?

The title says it all. I just cannot find any information about this - I have tried for so long now. Therefore, I figured that I could reach out to some clever guys in this forum for help instead:)

According to this https://wolfcrow.com/notes-by-dr-optoglass-dynamic-range-of-the-human-eye/ , human vision can cover a dynamic range of up to 30 stops (as photographers would call it), with essentially the upper 10 stops accounted for by the cones, the lower 20 stops by the rods. The info graphic on the referenced page also correlates this to cd/m² values, but we should note that the number of photons per cone/rod is also influenced greatly by the aperture (i.e., the iris) . Thus if we boldly take the minimum 80 photons from Dr S T Lakshmikumar's answer (which presumably applies to rods) and multiply it by 1,000,000, we arrive at ~$$10^8$$ photons as saturating rods and after multiplying with an additional factor of 1000 with ~$$10^{11}$$ photons for cones. Note that these are very rough back of the envelope calculations based on numbers drawn from totally different sources and without accounting for any further details such as relative dimensions of cones/rods, wave-length dependency and whatnot.