Compensation of the eye's aberrations with adaptive optics allows high resolution images and identification of individual cones in the living human eye. Such images, combined with psychophysical measures in the same eyes, reveal the effect of the trichromatic cone mosaic on color and spatial vision. Perhaps the most striking conclusion from this work is how little impact the topography of the mosaic has on vision, illustrating the brain's cleverness in concealing variations in cone topography from our visual experience. Application of adaptive optics imaging of the cone mosaics of color blind eyes in conjunction molecular genetics has revealed a new cause for color blindness. Finally, adaptive optics can also be used to probe single cones in the human eye with tiny flashes of light. This produces a striking variation of color experience from flash to flash that calls for a revision of prevailing models of human color processing.
David Williams, "Color and the Cone Mosaic" in Proc. IS&T 14th Color and Imaging Conf., 2006, pp 1 - 2, https://doi.org/10.2352/CIC.2006.14.1.art00001