[The resolution and discrimination of images in the visual system]

We analysed the conformity of optic and retinal cones anatomy factors by the two-point test. Obtained by F. Campbell and R. W. Gubish, the point spread function has a width of about 1 arc min. Cones sizes are equal to 0.5 arc min in the fovea. Functional pixel consists of 3-5 cones under the point spread function. Such an organisation in very useful in decreasing the samping noise of receptors. We carried out psychophysical investigations to show a consensus among the optic, receptors', and neuronal levels. In experiments we studied changes of the two-point pattern perception in respect to the points separation, measured the orientation threshold of small size stimuli. Data were compared with optical point-spread function, the hexagonal mosaic of cones, and line spread function of spatial elements, which form spatial frequency channels at the cortical level.