17:16 22 July 2016
Researchers from Rockefeller University and the Research Institute of Molecular Pathology in Austria have found evidence suggesting that the human eye is far more sensitive than had previously thought and that it is capable of detecting as little as a single photon in the dark, raising prospects that humans could have better night vision that we realise.
Dr Alipasha Vaziri, associate professor and head of the Laboratory of Neurotechnology and Biophysics at Rockefeller University, said: 'If you imagine this, it is remarkable - a photon, the smallest physical entity with quantum properties of which light consists, is interacting with a biological system consisting of billions of cells, all in a warm and wet environment,'
'The response that the photon generates survives all the way to the level of our awareness despite the ubiquitous background noise.
'Any man-made detector would need to be cooled and isolated from noise to behave the same way.'
Three men in their 20’s carried out more than 30,000 trials with one wearing contact lenses. Each time, they sat in a completely dark room while their heads are kept still using a headset. After 40 minutes to allow their eyes to fully adjust to the dark, they were instructed to fix their eyes on a dull red light. They were then shown two light stimuli from the machine – one where a single photon was fired straight into the retina and one where the gadget was totally dark. They were then asked which of the two had delivered the photon. The process was repeated numerous times and the three men were able to detect the photon 51.6per cent of the time.
Dr Vaziri said: ''What we want to know next is how does a biological system achieve such sensitivity? How does it achieve this in the presence of noise?
'Is the mechanism unique to vision or could it tell us something more general on how other systems could have evolved to detect weak signals in the presence of noise?'