From David Castelvecchi's 7-19-16 Nature article entitled "People Can Sense Single Photons":
"People can detect flashes of light as feeble as a single photon, an
experiment has demonstrated — a finding that seems to conclude a 70-year
quest to test the limits of human vision.
"The study, published in Nature Communications on 19 July, 'finally answers a long-standing question about whether humans can see
single photons — they can!' says Paul Kwiat, a quantum optics researcher
at the University of Illinois at Urbana–Champaign. The techniques used
in the study also open up ways of testing how quantum properties — such
as the ability of photons to be in two places at the same time — affect
biology, he adds.
"'The most amazing thing is
that it’s not like seeing light. It’s almost a feeling, at the threshold
of imagination,' says Alipasha Vaziri, a physicist at the Rockefeller
University in New York City, who led the work and tried out the
To read the rest of Castelvecchi's article, click HERE.