System for psychophysical measurements of two-photon vision

Two-photon absorption occurring in photoreceptors of the human eye is responsible for the perception of pulsed infrared laser beams. The color of perceived light corresponds to about half of the wavelength of a stimulating beam. This recently discovered phenomenon is called two-photon vision. However, it is yet not clear how such phenomena could impact an ophthalmic diagnosis and therefore further studies are required. In this paper we present the system that enables future psychophysical experiments to extend our knowledge about two-photon vision and its diagnostic value by identifying differences between two-photon and single-photon vision.