The Human Eye Could Help Test Quantum Mechanics

Harish Parthasarathy

Gabriele Bizzarri, Assunta Di Vizio, Matteo Rosati +2 more

The evolving understanding of the limits of human visual perception has advanced the development of optical devices that not only correct visual defects but also help manage changes in certain eye structures. As modern optical technologies allow precise control of the quantum properties of light, recent endeavours have started testing the quantum capabilities of human eye perception, proving that they can detect single photons. This paves the way for the application of quantum metrology and cryptography to medical imaging, with potential increase in precision and security.

R. Y. Chiao, Paul G. Kwiat, Aephraim M. Steinberg

Rita M.R. Pizzi, Rui Wang, Danilo Augusto de Albuquerque Rossetti

This paper describes a computational approach to the theoretical problems involved in the Young's single-photon double-slit experiment, focusing on a simulation of this experiment in the absence of measuring devices. Specifically, the human visual system is used in place of a photomultiplier or similar apparatus. Beginning with the assumption that the human eye perceives light in the presence of very few photons, we measure human eye performance as a sensor in a double-slit one-photon-at-a-time experimental setup. To interpret the results, we implement a simulation algorithm and compare its results with those of human subjects under identical experimental conditions. In order to evaluate the perceptive parameters exactly, which vary depending on the light conditions and on the subject's sensitivity, we first review the existing literature on the biophysics of the human eye in the presence of a dim light source, and then use the known values of the experimental variables to set the parameters of the computational simulation. The results of the simulation and their comparison with the experiment involving human subjects are reported and discussed. It is found that, while the computer simulation indicates that the human eye has the capacity to detect the corpuscular nature of photons under these conditions, this was not observed in practice. The possible reasons for the difference between theoretical prediction and experimental results are discussed.

Rebecca M. Holmes, Michelle Victora, Ranxiao Frances Wang +1 more

The human eye contains millions of rod photoreceptor cells, and each one is a single-photon detector. Whether people can actually see a single photon|which requires the rod signal to propagate through the rest of the noisy visual system and be perceived in the brain|has been the subject of research for nearly 100 years. Early experiments hinted that people could see just a few photons, but classical light sources are poor tools for answering these questions. Single-photon sources have opened up a new area of vision research, providing the best evidence yet that humans can indeed see single photons, and could even be used to test quantum effects through the visual system. We discuss our program to study the lower limits of human vision with a heralded single-photon source based on spontaneous parametric downconversion, and present two proposed experiments to explore quantum effects through the visual system: testing the perception of superposition states, and using a human observer as a detector in a Bell test.