Let me up the ante, not only can we detect single photons.
A pioneering study at the interface of biology and physics found, that isolated rod photoreceptors of frogs are sensitive to differences in the light sources statistical properties, e.g coherent (laser) vs thermal (sun, light-bulb) vs sub-poissonian (resonance fluorescence of quantum dots) light statistics:
"Measurement of Photon Statistics with Live Photoreceptor Cells" (2012) [1]
"The results indicate differences in average responses of rod cells to coherent and pseudothermal light of the same intensity and also differences in signal-to-noise ratios and second-order intensity correlation functions"
It seems Lorentz hypothesis in 1911 was right, that the boundaries of our perception are set by basic laws of physics, and that we reach the limits of what is possible.
The eyesight of mantis/pistol shrimp is similarly crazy in it's complexity and it's in an invertebrate. Evolution seems to pick out some crazy stuff when it comes to animals near the water-air interface. For instance, they are able to detect circularly-polarized light across multiple octaves of light with a single receptor, covering all the Stokes' vectors. I've done a fair bit of optics and I have NO idea how to begin constructing a quarter-wave plate that would cover multiple octaves. So crazy.
I can't find what this Lorentz hypothesis of 1911 is, but surely you are claiming too much. Physical entities can detect X-rays, but humans haven't evolved that ability (except, recently, externally/collectively).
The idea that our perceptual apparatus is optimal, rather than a contingent product of a particular evolutionary path, is easy to refute -- but maybe that isn't what you mean by "reach[ing] the limits of what is possible."
OK, by way of acknowledgement of splittingTimes' downvoted clarification, it seems the phrase "the boundaries of our perception are set by basic laws of physics, and that we reach the limits of what is possible" comes verbatim from a text in which the context is clearly the detection of photons. So it wasn't intended to be a claim of optimality for the human perceptual apparatus in general.
A pioneering study at the interface of biology and physics found, that isolated rod photoreceptors of frogs are sensitive to differences in the light sources statistical properties, e.g coherent (laser) vs thermal (sun, light-bulb) vs sub-poissonian (resonance fluorescence of quantum dots) light statistics:
"Measurement of Photon Statistics with Live Photoreceptor Cells" (2012) [1]
"The results indicate differences in average responses of rod cells to coherent and pseudothermal light of the same intensity and also differences in signal-to-noise ratios and second-order intensity correlation functions"
It seems Lorentz hypothesis in 1911 was right, that the boundaries of our perception are set by basic laws of physics, and that we reach the limits of what is possible.
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[1] [pdf] https://physics.aps.org/featured-article-pdf/10.1103/PhysRev...