A system for examination of an eye of a subject includes a laser for irradiating a select portion of the retina with a short pulse light having a wavelength of about 800 nm to about 1400 nm at an intensity effective to stimulate two photon induced isomerization of visual pigments in the select portion of the retina of the subjects eye, and an input device to permit the subject to input a reaction or response of the subject to the irradiating light.
