Direct naked-eye detection of chiral and Faraday effects in white light

We demonstrate that the human eye is able to detect the optical activity of chiral molecules and the Faraday effect, even under white-light viewing conditions, without the help of any polarizer. Indeed, we show that our eye acts as a differential analyzer and isolates the response in the blue part of the visible spectrum, thus avoiding the difficulties related to the inherent chromatic dispersion encountered in usual experiments performed under white-light conditions. Moreover the human eye enables to clearly distinguish between the fundamental reciprocal and non-reciprocal characteristics of the optical activity and the Faraday effect, respectively. Furthermore the human eye, without any specific optical dichroic axis in the retina, enables us to read, with the naked eye, hidden information encoded via different states of polarization, and suggests the possibility of direct detection of quantum entanglement effects.