The above figure represents the trichromatic spectra corresponding to the three “classes of cones” that, in the “standard or historical model” are thought to represent the response of cone receptors on the retinal surface. I have referenced this oft-quoted figure elsewhere on the web page asserting (the red “X”) that short wavelength sensitive (“S” or blue sensitive) cones do not exist. In fact, it is my claim that no such thing as “classes of cones” exist.
In this work I derive three peaks of light sensitivity on the retinal surface that, at first glance, seem similar to the above. These are presented as Figure 3 of the full paper linked to the web page. At first blush these three peaks might be confused with the above BUT THEY REPRESENT SOMETHING ENTIRELY DIFFERENT. This, in fact, goes to the essence of my hypothesis.
If one, for example, focuses on the mid-band peak in the above figure (that corresponds to green at ~550 nm).one imagines that wavelengths interacting on either sides of the peak correspond to “shades of green blending into a rainbow of mixed colors as red and blue are added“. This is the normal interpretation of a “spectrographic plot” as the above represents. One goes on then to imagine that the myriad of colors conjured up by this view corresponds to the colors that we see, i.e., that the retina is the direct analogue of color photographic film.
This is not, however, how I propose the retina functions.
The three light sensitive regions on the retina that I derive, using the historically measured distribution of cones and rods on the retinal surface (Osterberg, 1935), result from simply counting cone and rod receptor appositions at each retinal angle… and assuming that light interacts between receptors. The three “curves” then are totally different representing light sensitivity as a function of retinal angle (as measured from the fovea) and not as a function of wavelength as the above.
My central “mid-band” response curve (whose peak is now, importantly, geometrically defined at a specific retinal angle on the retinal surface to satisfy Edwin Land’s prediction) corresponds in it’s entirety to only one wavelength (or “the same shade of green”) at each point, What varies on either side of the peak of this curve on the retinal surface is a variation of the density of detection sites, Such a variation in density corresponds to different levels of brightness (or, using the term used by Land, “lightness”) of light detected at this color. THIS IS EXACTLY WHAT EDWIN LAND DEDUCED FROM MEASUREMENTS MADE EXTERNAL TO THE EYE!
The retina then detects, from the fovea to a retinal angle of approximately 20 degrees, the brightnesses of three narrow wavelengths (or colors). We term these three colors “primary”.
The function of the retina is then NOT to discriminate a wide variety of colors but rather to detect only three primary wavelengths (or colors) that are directed to it by the refractive properties of the eye… what has been erroneously termed chromatic abberration. This is the basis for the historically measured (and never explained) distribution of cones and rods on the retinal surface and the fundamental reason why they evolved in this way. THE NEVER EXPLAINED, STRANGE DISTRIBUTION OF CONES AND RODS ON THE RETINA IS IN CONSONANCE WITH, AND EXPLAINED BY, THE LIGHT REFRACTIVE PROPERTIES OF THE BODY OF THE EYE.
Beyond this, the eye performs three Fourier or optical transforms of the acquired data synthesizing the color image as discussed in the full paper.