Rethinking the Process of Vision

A poster/paper (3832/A375) was presented at the ARVO 2008 Annual Meeting “Arrangement of the Human Trichromatic Cone Mosaic in Peripheral Retina” authored by O. Masuda, H. Hofer, J. Carroll and D.R.Williams. I interpret this work extending the imaging methodology developed by the authors (and previously by Roorda et al) to larger retinal eccentricities, as being in some way a response to my repeated requests that this measurement be made. But….who knows?

I humbly submit that their results seem to verify my projection in their finding of a “clumping” of, what they (erroneously) term L and M “cones” at retinal eccentricities of 10 degrees. They note that this represents the first instance where the packing arrangement of cones is distinguishable from randomness, i.e., that a spatial order is observed. Their exact statement “Previous studies have concluded that the packing arrangement of L and M cones near the center of the human fovea is not distinguishable from random in most eyes”. (does this mean that the packing arrangement in “some” eyes is not random? – please supply a reference?).

I believe that the basis for what they are observing follows directly from my observation that is calculated directly from Osterberg’s measurements of retinal morphology showing that the maximum (at this point complete!) degree of spatial order appearing as a motif of eight rods surrounding each cone. This perfect geometric array following Osterberg occurs near this eccentricity (really at 7-8 degrees but they are close enough). The interplay of cones and rods at this eccentricity is not statistical anymore but completely ordered! I have proposed that this octagonal motif forms a fundamental (termed “primary”) mid band (“green” or in their terms an “M cone”) light interaction point on the retina. In my explanation this complete degree of geometric spatial order translates into the peak of intensity of the primary mid band wavelength and forms the 550 nm wavelength mid band reference point on the retinal surface. I have proposed that the identification of this geometric reference forms the basis for the color constancy of vision. The eye interprets the exact middle of the visual band geometrically! The retina is not a spectrometer!

I will not go into this much further only noting that the sample size of their images is so small that the statistical nature of the distribution of cones and rods is seen (Osterberg again!). This is as to be expected and they note this. The first degree of order (or “clumping”) that they observe at the 10 degree eccentricity in these statistically small images represents the “tip of the iceberg” of the spatial order that exists at this eccentricity. Their quest for an ordered “mosaic” on the retina, and any idea as to how the randomness that they have observed (until now!) could lead to an image formation mechanism, totally eludes me. I would like to see the reasoning behind this?

The spatial resolution of their imaging methodology and the question why they do not observe rod receptors? I have addressed this in a previous Comment. Suffice it to note that they claim 2 micron resolution which would be approximate the diameter of the inner segment of a single cone and should be sufficient to image rods .

Again, I would claim what they are actually imaging at this eccentricity is a motif of eight rods around each cones. This “M cone” should be really be termed an “M wavelength detection center”

Added on 5/14/08

The authors also undertake a curious (to me) effort to measure the distances between cones apparently to verify the randomness of the distribution. I do not understand why they apparently want to verify what already is, and should be, apparent as the statistical randomness following from the Osterberg morphology data? Their words: “We evaluated the packing arrangement of the 3 cone classes by comparing frequencies of distances between all cones of the same type with those expected based on a random pigment assignment rule”

To be clear - the foveal region that contains > 99% of cones on the retina, and where they want to see a differentiation of these cones into “classes”, is totally “L wavelength” sensitive. Then as rod receptors begin to intrude into the receptor array at the edge of the fovea at eccentricities of one degree a statistical distribution of L and a few M (cone/rod appositions) begins to be seen. At this point if one does not want to believe the data of Osterberg see the figures of George Wald! The author’s measurements until this paper were made at eccentricities of one degree and they observe exactly what they should observe. I would note on the subject of “S” or blue sensitive “cones”, again statistically, here and there an apposition of two adjacent rods will be observed ..and voila, an “S” cone! This is the explanation for the strangely small density of this type of “cone”.

My finding of the three primary wavelength peaks on the retina follows from a simple counting of receptor appositions using Osterberg’s morphology data. Any grad student could do a statistical analysis of the presence of rod/rod appositions in near foveal region (at an eccentricity of one degree as measured by Roorda) and I project that the density so calculated would correspond to these measurements of “S Cones”.

Respectfully submitted.

GCH

5/14/08

I have been enlightened as to the “actual mechanism” of light interaction with retinal receptors that, surprisingly,  this process even today is thought to invoke the concept of treating the receptor as an optical (or fiber optic) waveguide. I had believed that viewing receptors as waveguides was in the past as it has never after significant theoretical study led to any new insights into the vision process. In any event, I am informed that it is contemporary thought that the body of the receptor acts as such a waveguide directing light as a wave (waveguides direct light as a wave!) to the point of interaction with pigment molecules. Additionally, I am informed in no uncertain manner that the smaller rod receptors “are known not to be very effective waveguides”. This is given as the reason why no rod receptors (read none!) are seen in the pseudo colored “cone mosaic” images that are the basis of the work of Roorda et al ⁽¹⁾ and more recently of Masuda et al ⁽²⁾. I was further told that these images are not the light interactive outer segments of the “cones” but are actually of their inner segments! The images follow from (somehow?) the aforesaid classical  guiding of light as a wave through the inner segment  and  after retro-reflection following  light passage through the outer segment where light interaction is known to occur. The function of inner retinal segments (that are somewhat larger in diameter than the outer segments) functions not to interact with light but to serve as a “genetic factory” for the continuous production of the thylakoid disks that form the outer light interactive segment. ?

So to try to summarize this, it is assumed that the receptors of the retina act as light waveguides (which, incidentally, treat light as the wave of classical physics!) and posits that, after light enters the receptor through the inner segment  finally arriving at the outer segment where the light interaction process occurs. One must assume that, in physics terms, the wave/particle duality “happens” (or using Stapp’s statement “a miracle occurs”) somewhere in this passage, the radiation becomes a photon/particle and, following this, interacts with retinal pigment molecules. Vision theory then proceeds into such nonsense as explaining the extraordinary length of receptors , and the stack of thylakoid disks contained within, functioning as some sort of  “photon catch” configuration whose function is to enhance the absorption of photons! This scenario does represent long accepted physics but this is now being superseded as I will show by recent results in nanotechnology. It will become clear that we are now entering an era that will change our views of a great many areas of science - including vision.

In the imagery of Roorda/Masuda (that I am informed has a spatial resolution of 2 microns or a little greater than the diameter of a single cone) rod receptors do not appear at all although they are present in greater numbers than cones, have inner segments and diameters approximating half that of cones, and would seem to somehow, according to well measured retinal morphology (Osterberg and others), “fill up space” in the images of the presented retinal morphology…?? The reason given for the non-appearance of rods is that they, as noted above, “are not very effective waveguides”.

Is any of the above logical?

Enter some modern physics – please!!!!

Historically, there have been any number of treatments of retinal receptors as light waveguides. Noting the work of Jay Enoch and B.R. Horowitz will suffice. It will be crucial to note that these analytical studies - and the above modeling so posits - considered waveguide diameters in the traditional sense used in contemporary fiber optic technology where we assume that light is guided totally within the fiber itself. I would note, parenthetically, that these studies over the years never led to any new insights into the vision process– until I was informed that this modeling is accepted today. This came as a total surprise!

But, enter the modern world. It has been experimentally found as early as 2004, and reported by a Harvard group ⁽³⁾ that when the diameter of the optical fiber is reduced to micron or sub-micron dimensions (i.e., the wavelength of light) light is guided outside of, or around, rather than inside, the body of the optical fiber.

And…these are fiber light guides that are of the dimensions of retinal receptors.

This result directly supports my explanation where light as a wave interacts between adjacent to what will in physics be termed quantum confined electron centers or nanowires - the body of the receptors.

Further in this mode, it is observed that the evanescent field (i.e. the field orthogonal to the direction of light) is enhanced which exactly supports my explanation regarding energy transference to the retinal/rhodopsin complex that is dichroically oriented in this direction within receptors.

GCH

5/12/08

Regarding a Letter to Nature (Nature, Vol. 397, 11 February 199, pp520-522)

This letter titled “The Arrangement of the Three Cone Classes in the Living Retina” by Roorda and Williams is interesting. This (and remember that it is published in 1999) represents the traditionally held view that “Human colour vision depends on three classes of receptor, the short (S), medium (M), and long (L) wavelength-sensitive cones”. The paper then goes on to state that ” these cones are interleaved in a single mosaic” so that “at each point on the retina only a single class of cones samples the retinal image”. I readily admit that I do not know what this means! They seem to assume (as has the history of vision) that the retina acts as the intensity-only sensitive “image plane” of the optics of the eye. This is the plane where photographic film is placed in our camera technology. If this were so, however, there would have to be some logical spatial order to the three light detection centers - as the RGB triads or stripes used in television imaging tubes or camera CCD surfaces. But…there is none of this on the retina - only Osterberg’s asymmetric array of cones and rods. What on earth is assumed here? How is an image (and ,even further , a color image) formed? Is there some logic here that is eluding me?

Incidentally, the asymmetric distribution of cones and rods as measured by Osterberg in 1935 forms the exact basis for my explanation of light interaction with the retina and the genesis of color vision. The meaning of this distribution seems to be explained for the first time

A further sentence in the Roorda Letter states that “although the topography of human S cones is known ^{2, 3}…...” (p.520). If this statement were accurate, namely that the so-called S cones have been shown to exist and that they are arranged in some known topography, I would would have to concede that my explanation of the vision process was incorrect.

I humbly submit, however, that a review of the references cited ( #2 an #3 as noted above), that purportedly support this contention, do not seem at all to do this!!!! I stand to be enlightened but this is my reading of the references.

The Williams reference ² is simply inconsistent with their statement. In the reference, and after considerable effort, a single cone receptor is finally located which is defined as an S cone. One might question how this finding can be reconciled with the assertion that a known topography exists. How is one to ascribe a topography to a single cone?

The Curcio reference ³ is even more curious, again, not at all supporting the statement. This paper relates a much more intensive effort than pursued by Williams to seek the elusive S cone using a number of diverse approaches. But the concluding comment of the paper is most telling stating that “all of the evidence (for the existence of the S cone) must be viewed as inferential only” . The italics are mine but this is the exact term used in the paper. I really do not understand what this means but it is certainly not very positive about the existence of the S cone (or a topography)!

One more note about this piece – as the authors state, their measurements were consistently made “at a retinal eccentricity of one degree nasal from the foveal center”. This region, i.e., at the “edge” of the fovea, is the retinal angle at which there is a greatest interplay of cones and rods – cone density is rapidly diminishing and rods are being introduced into the admixture (again, please take note of the historic data of Osterberg). I would therefore expect to see what R&W imaged at one degree! The pseudocolored images that they present as Figure 3 (p.522) represent exactly what I would expect composed of predominantly red centers representing the long wavelength sensitive cone/cone appositions of the fovea, some number of green centers entering the picture representing the gathering statistical number of cone/rod appositions (and that geometrically define mid band wavelength), and a far fewer number of blue centers characteristic of the, still random at this angle, pairing of rod receptors.

I therefore would agree with the validity of their experimental method recognizing that their measurements were made at one degree of retinal angle. And….these findings at one degree of angle….are in complete consonance with my explanation for light interaction with the retina - and with the long accepted morphology of receptors on the retinal surface.

THERE IS, HOWEVER, ONLY ONE PROBLEM - THE WAVELENGTH DETECTING CENTERS THAT THEY IDENTIFY DO NOT REPRESENT CONES BUT RATHER RECEPTOR APPOSITIONS.

I would propose that if they made a similar type of measurement at 7-8 degrees of retinal eccentricity they would find, accepting that their experimental methodology was correct, that green centers would predominate.

GCH/Ojai,CA

5/7/08

REFERENCES

¹A. Roorda, and D.R.Williams, Nature, 397, No.11, February 1999

² Williams, D.R. et al “Punctate Sensitivity of the Blue Sensitive Mechanism”, Vision Res, 21, 1357-1375, (1981)

³ Curcio, C.A., et al “Distribution and Morphology of Human Cone Photoreceptors Stained with Anti-blue Opsin”, J. Comp. Neurol.,312, 610-624, (1991)

A definition from Wikipedia of the unique color constancy of the vision process”

“Color constancy is an example of subjective constancy and a feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions. A green apple for instance looks green to us at midday, when the main illumination is white sunlight, and also at sunset, when the main illumination is red. This helps us identify objects.”

In striking contrast, color photography does not possess this characteristic where the color of an object is not constant but is altered by changing ambient illumination. Color photography requires that filters be used to correct for this effect and render the object of interest close to its’ “true” color.

The vision process possesses color constancy. Color photography does not.

I have written proposing an explanation for this visual characteristic and the reader is referred to Comment of March 3, 2006 on this subject.

Clarifying those thoughts - it follows from Osterberg’s historic retinal morphology measurements and the antenna premise of this work that the exact mid-band point of the visual band (i.e., 550 nanometer) is geometrically-defined on the retinal surface at an eccentricity of between seven and eight degrees. This corresponds to the eccentricity where sufficient rods are present in the retinal motif to completely surround each cone (Osterberg’s data and figures). This provides the fixed reference that Land termed a “fulcrum” from which all other wavelengths of the visual image are compared to produce the hues of “color”. I propose that this fixed wavelength reference provides a basis for explaining the color constancy of the vision process.

I would add that this precise location defines the peak intensity of 550 nm midband wavelength radiation being the location of the maximum density of optical interactive antennas (cone-rod appositions) on the retinal surface. It is the intensity distribution across this band (and across the other cone-cone and rod-rod bands) that Land termed “lightnesses” compared by vision to create the hues of color.

As I have noted, these wavelengths are indeed “primary” but they do yet represent “color”.

Fundamental geometry!

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SUGGESTION FOR INVESTIGATION:

Check the validity of my statement that the 550 nanometer wavelength falls on the retina at an eccentricity of between seven and eight degrees. In a very preliminary effort using LIGHT TOOLS software (Optical Research Associates, Pasadena, CA), and entering the optical parameters of the structures of the eye , it very quickly becomes apparent that this wavelength is incident on the retina at this eccentricity. Subsequent to this effort, I visited with an individual in vision studies who had generated a far more comprehensive simulation than mine (I believe directed to support of the LASIK procedure). I do not feel able to quote this individual as he said that he had not published the data. In any event his simulation showed that 550 nm interacted at precisely the 7-8 degree eccentricity point on the retina. Someone should follow this up!

5/2/08

The following text is abstracted from Wikipedia:

“Scotopic vision is the monochromatic vision of the eye in dim light. Since cone cells are nonfunctional in low light, scotopic vision is produced exclusively through rod cells. Vision in normal light with functioning rod cells is photopic vision”.

That “cone cells are non-functional (or shutdown?)…” there is just no experimental evidence for such a statement! One would reason this way if one believed that cone cells are the source of color…which they, clearly in this explanation, are not! “Scotopic vision is produced exclusively through rod cells”… how on earth? …invoking what mechanism? Scotopic and photopic vision are therefore presented as two separate systems. What physical evidence is there for this statement? From the viewpoint of my geometric explanation all of this is completely erroneous and leads one down the wrong path of thought… and has done so for years and years, i.e., the fallacy that “cones detect color and rods black and white”! It attempts to explain phenomenologically the behavior of the vision process but, in fact, uses the completely wrong mechanisms.

There is really only one system, but, if one must use these terms these are the proper definitions:

Scotopic vision: “Under low light level conditions the rod receptors of the peripheral retina are linked together (as experiments show) to act as a “wide angle light meter” with the exact short wavelength limit of visual response (~400 nm) controlling pupillary constriction, dilating the pupil of the eye and admitting the maximum amount of light to the retina. Under these conditions light intensities of the three primary RGB wavelengths falling on the the retina are insufficient to activate the “Land color mechanism”, i.e., there is insufficient intensity incident on either side of the geometrically determined mid-band (550 nm) reference point at 7-8 degrees of retinal eccentricity to allow a ratio to be obtained and the hues of color perceived. The historic misconception that “rods detect black and white” is explained.

Photopic vision: “Under normal daylight levels of illumination the three primary RGB light intensities abstracted by the retina are sufficient to activate the “Land color mechanism” as defined above and the image including the hues of color is perceived. The peripheral rods, as above, constrict the pupil  controlling the intensity of light entering the eye to levels that will not damage the retina”.

There is only one “system”!

GCH

4/25/08

I was reminded of Edwin Land after seeing his picture in the Business Section of yesterday’s New York Times. When I began this work on vision in 1991 one of the first things I remembered were Land’s anomalous color vision experiments of the 1950’s that derived a full color image from the superposition of two black and white negatives. This strange result even rose to the pinnacle of popular science at the time ascending to the cover of Scientific American (May 1959). Edmund Scientific (for those who will remember!) even sold kits of these negatives so that one could perform this feat at home. I felt certain that in the forty intervening years vision science would have provided an explanation. It became clear, however, that not only had the experiments not been explained but Land’s name had almost completely disappeared from the literature of vision!

In one exchange with a prestigious university group engaged in vision research I was told early on that “the field had put Land’s work to bed years ago” and I was pointed to a paper by Walls with the curious title that shouted “LAND! LAND!”. This paper had been published in Physiological Bulletin (Vol. 57, No. 1, 1960). Incidentally, this reference does not seem to appear associated with Walls’ publications on the web. I dutifully obtained the paper and was distressed to find that it consisted of page after page of ad hominem attacks on Land and his experiments damning him with faint praise as an “inventive genius” (read “not a scientist”). Land’s experiments generated a great deal of excitement at the time with Walls quoting, generally without attribution, the numerous (and admittedly exaggerated) popular claims made about the work (statements made such as “scientists since Newton have been completely fooled about the way that the eye sees color”). After setting the stage with an entire column of these claims, Walls finally notes that Land has disavowed them! The remainder of the fourteen pages of the paper is replete with quotation marks essentially mocking Land’s work. In my view, even after this lengthy rant, he never provides an explanation for the experiments! In summary, this paper is certainly not objective science. So much for that!

I will not here attempt a complete characterization of Land’s work on color vision. Suffice it to say that his conclusions, drawn from measurements made external to the eye are, I believe, now explained by the geometric/optical antenna finding of my work. The parallels are dramatic – his observation that a wavelength dividing “fulcrum” must be present somewhere in the vision system is seen to correspond to the geometrically defined mid-band point at 7-8 degrees of retinal eccentricity that I geometrically define. Importantly, this fixed reference also explains for the first time the “color constancy” of vision. Land demonstrated, again from measurements made external to the eye, that the many hues of color are obtained by the eye calculating a ratio of light intensities (Land termed them “lightnesses”) on either side of this mid-band fulcrum point. This is the first place where the term color should be introduced in the vision process! Although Land deduced this without knowing the light interaction mechanism internal to the eye, my geometric explanation shows that the retina is sensitive to light intensities (his “lightnesses”) in three fixed- wavelength (RGB) bands and that these correspond to what have historically been termed the “primary colors”. One sees now, however, that these three wavelengths should not be termed “colors” at all reserving that term for the above defined ratio of light intensities on the retina.

In his work Land had available only the traditional model for light interaction in the eye. He proceeded, in the only way open to him, to develop an algorithmic theory – that he termed the “RETINEX” - to simulate the results of his color vision measurements. This work is a relatively difficult to follow and perhaps not necessary with this new corroborative understanding of the retina and the eye.

I have suggested that anyone interested in Land’s work should request the complete compendium of his papers from the Rowland Institute in Cambridge, MA that Land founded (that has now been subsumed into Harvard). These papers were sent to me in the early 1990’s by Holly Perry then in residence and who had been an associate of Land. She may have retired by by now but she was very helpful to me at the time. A review of these papers reveals the lucidity and true method of scientific inquiry characteristic of Land’s work. One must see the true character of scientific pursuit in this work! I have seen this only once before and that was in the writings of the physicist David Bohm!

One might also read Victor McElheny’s book “INSISTING ON THE IMPOSSIBLE - THE LIFE OF EDWIN LAND” (Perseus Books). Chapter 14 of the book describes in some popular detail Land’s color vision experiments. A quote (p.258) attributed to Land is particularly interesting here:

“Land spoke of the eye’s using light reflected from the scene to form at least two ‘identical but separate records of the scene’ one with longer wavelengths and the other with shorter” .

This is exactly where my explanation of light interaction with the retina leads. The dividing point between the two regions is the geometrically-determined wavelength reference at 7-8 degrees of retinal eccentricity (the exact center of midband G intensity that explains color constancy!) with Land’s long and short color vision records determined by ratioing intensities on either side.

It is my belief that Edwin Land was the true scientific genius of the field of color vision. His work should, and certainly will ultimately, be recognized!

Respectfully,

Gerald C. Huth, Ph.D.
Ojai, CA

Beginning with my interest in the concept that light interacts with spatial antenna dimensionalities proposed in a U.S. patent (Marks) it became clear that, when applied to the retina of the eye, this type of spatial interaction explained a great deal that had been heretofore left unexplained in the vision process. Examples include providing a basis for understanding the anomalous color vision experiments and reasoning of Edwin Land, an explanation for the longstanding conundrum of color constancy in vision, the primal cause of the medical condition termed macular degeneration, and the processes involved in color variant vision (color blindness). Parenthetically, it also became clear that the retina of the eye evolved as the direct biological embodiment of the principles of the diffraction of light – nothing more! All of this is discussed in Huth. Specifically, it is seen that light interacts as the wave of classical physics in the space between receptors and not in the body of the receptors themselves that has for so long assumed. In the retinal structure these light wave-accepting spaces are immediately adjacent to quantum confined electron (EQC) spaces (formed by the receptors themselves) that constitute the absorbing mass. It is then seen that the rhodopsin protein within receptors has a structural function in conducting light energy to the signal-producing isomerization of the retinal molecule. Using this construction it immediately becomes clear that the plan of the retina actually forms a geometrically-defined 2-D Fourier transforming surface whose properties follow directly (calculated) from the historically measured, and oft quoted, asymmetric morphology of retinal receptors (“Cone-Rod Distribution in Human Retina”, G. Osterberg, Acta Opthalmologica, 1935).To my knowledge this is the first time that Osterberg’s data has been explained rationally. Harris in a recent proposal has also concluded that the retina is a Fourier surface.

The human eye possesses the remarkable and well documented ability to discern the interaction of single photons (Rose) but the mechanism involved in this biological structure has never been forthcoming. I propose that this gives, or should have given, credence to the idea that quantum theory is somehow involved in the vision process. We really must give thought to this! My work may provide an answer in positing that the vision process actually operates in at least two distinctly separate time domains. The first: TIME DOMAIN A is located at the outer segments of retinal receptors where the initial light interaction occurs. This interaction is in very fast time indeed it having been shown (Hamm ) the first step in vision - the cis-trans isomerization of the retinal molecule - occurs in femtoseconds (10^-15 sec). In the subsequent TIME DOMAIN B, signal processing involves slower ionic mechanisms characteristic of the biological sub-retinal “circuitry” and in transit through the optic nerve. This time domain has the function of “slowing down” the visual image information to human nervous system proportions. Times here approximate milliseconds (10^-3 sec). Consideration of time and space involved in A. defines this as a “quantum domain” interaction. Might it be therefore that it is light interaction with the outer segments of retinal receptors that represents the interface between quantum reality (whatever that turns out to mean!) and the human system. The slower, millisecond, reaction of B has long been misunderstood as the “reaction time of the eye”.

The retinal outer segment light detection centers (“devices”) that I have defined , comprising sub-micron interreceptor spaces and EQC centers, conceptually possess electronic properties (capacitance, etc.) consistent with signal response in this time domain. Electronic noise is a time integrated function. Viewing light interaction (signal generation) in times as short as femtoseconds brings in the role of time (Tove and Huth) in reducing electronic noise. This effect may explain the extraordinary sensitivity of the visual process.

I have proposed that the retinal outer segment devices possess the ability to detect light intensity and phase as required by the Fourier equation. This follows from the initial geometric explanation of the plan of the retina as a diffractive Fourier surface based on an “antenna” model. Such a surface encoding light intensity and phase behaves as (or is the definition of) the phase conjugate “mirror” (Phase Conjugation) so well known in the laser field. Such a mirror surface reflects each light ray back upon the exact path on which it entered, in this case, the eye, and in the process eliminates the effect of scattering. The retina acting as such a surface, as I believe, would explain the longstanding conundrum as to why the outer segments seem to “point the wrong way” ( for example, a recent paper (Svet) discusses the problem of image distortion by light scattering in passing through the sturucture of the inner segments of retinal receptors). These thoughts lead, in turn, to perhaps the idea that the eye, instead of being the passive receiver that has for so long been assumed, may actually re-radiate a signal that corresponds to the visual image back into the external environment/world along the phase conjugate path, It is well understood that antennas in addition to detecting electromagnetic radiation can equally well transmit such radiation. Might the eye actually transmit? And, if this were so, might this provide an “interconnectedness” with the external environment relevant to the subject of consciousness? I have made the point above that the plane of retinal outer segments where initial light interaction occurs can by definition be said to operate in the space and time realm of quantum physics. Might this plane be the “Heisenberg Cut” –the point an observed system from an observing apparatus in the Copenhagen interpretation of quantum theory – the point .that divides the probability wave nature of quantum reality with the classical reality of macroscopic “things” that we see and feel everyday. I’ll not go further into this deep (!) subject but will add the following quotes that seem to show that others have thought along these lines:

“Von Neumann tackled these problems by considering an idealized situation
in which there is a sequence of measuring devices, each probing the output
of the device that precedes it in the sequence, and by then following the
causal chain first into the retina of the observer, and then into the optic
nerves, and then ever deeper into the brain until at last the entire brain of the
observer is treated quantum mechanically, along with the rest of the physical
universe”.(italics mine / GCH)

“Quantum mechanics rationally accommodates, therefore, a two-way causal linkage between mind and brain, whereas the concepts of classical mechanics provide no rational foundation for a causal connection in either direction. Quantum mechanics leads, consequently, to a radical revision of the conception of man. Whereas classical physics reduces man to a machine, quantum mechanics allows man to be an injector of physical counterparts of mental concepts into the structure of the physically described world. Physical counterparts of mental concepts can be identified and honed into brains by trial and error learning”.
(Henry P. Stapp, “MIND, MATTER AND QUANTUM MECHANICS”, Second Edition)

Submitted:

Gerald C. Huth, Ph.D.,
Ojai,CA
4/9/08

The retina of the eye is shown in this simple geometric explanation to detect three – and only three –  wavelengths of light  and these are detected on the retinal surface in circular bands that surround the central fovea. Further, it is the intensity of these  wavelengths that varies across each band. Traditionally, we have termed these three wavelengths “primary” and then, inappropriately, proceed to call them “colors”. At this point in the vision process these wavelengths represent only the basis for the subsequent synthesis by the eye of the endless hues of color that we see.

This explanation for light interaction with the retina is consistent with, and for the first time makes sense of, the 1935 work of Osterberg who recorded in detail the asymmetric morphology of cone and rod receptors on the retinal surface.

As described in the body of this work, the assumption that light is absorbed via spatially-dimensioned “antenna” structures, together with a simple geometric insight, shows that the retina actually functions as the Fourier plane of the optics of the eye in contrast to the historic and incorrect assumption that it is an image plane (as in a camera). Vision is shown to be a diffractive Fourier-transforming process.

With this view of the retina in mind it becomes apparent that Edwin Land’s work on color vision, without any knowledge of the retinal structure that I propose, was brilliant indeed! Land posited from measurements made external to the eye that a fixed reference point (that he termed a “fulcrum”) must exist somewhere on the retinal surface. It becomes clear in this work that this is the geometrically determined mid-band point at 7-8 degrees of retinal eccentricity where the density of rods is sufficient to completely surround each cone. This is a fixed reference point where the detection and the refractive properties of the lens and body of the eye coincide! All subsequent color processing is made relative to this fixed reference wavelength.

Land further deduced that the hues that we term color were determined by a ratio of the light intensities incident on either side of this fixed point - a deduction that is also consistent with this explanation. Land further found in simulations based on his model that any, even slight, shift in the position of this point on the retinal surface would drastically alter the perception of color. (please review Land’s work for further understanding here). To say again, refraction in the lens and body of the eye is directs the mid band wavelength (~550 nanometer) to this specific angle on the retina that has evolutionarily been defined to be geometrically tuned to this wavelength.  This is the point on the retina  at 7-8 degrees of retinal eccentricity where the “pure” eight-around-one motif of rods around cones exists (see Osterberg). It should be obvious that any alteration in the ratio of the diameter of cones to rods, occasioned by a change in the diameter of either one, would cause this crucial reference to be moved to a different retinal eccentricity thus affecting perception of color. The same result might be a result of a change in the shape of the eye that would cause the mid- band wavelength to be refracted to a different point on the retina. I believe, however, that the former is more logical.

I would propose therefore that a change in the ratio of the diameter of cones to rods is a logical cause of what is termed color variant vision. In modern times it has become fashionable to invoke a genetic explanation to explain this visual condition (and most everything!). Genes express proteins and one should look to the specific genes that express the proteins that determine the diameter of the outer light interactive segments of the retinal receptors to understand the cause of this visual abnormality. So, at the basis, it a genetic effect but this explains nothing about the mechanism involved.

I am indebted to Peter Kaiser (“Human Color Vision” Second edition, Kaiser and Boynton) for introducing me to the term “color variant vision”. It really is not a “blindness” at all but just another unfortunate term that has been introduced into the science of vision.

GCH

3/02/08

Regarding a Letter to Nature (Nature, Vol. 397, 11 February 199, pp520-522)

This letter titled “The Arrangement of the Three Cone Classes in the Living Retina” by Roorda and Williams is interesting. This (and remember that it is published in 1999) represents the traditionally held view that  “Human colour vision depends on three classes of receptor, the short (S), medium (M), and long (L) wavelength-sensitive cones”. The paper then goes on to state that ” these cones are interleaved in a single mosaic” so that “at each point on the retina only a single class of cones samples the retinal image”. I readily admit that I do not know what this means! They seem to assume (as has the history of vision) that the retina acts as the intensity-only sensitive “image plane” of the optics of the eye. This is the plane where photographic film is placed in our  camera technology. If this were so, however, there would have to be some logical spatial order to the three light detection centers - as the RGB triads or stripes used in televison imaging tubes or camera CCD surfaces. But…there is none of this on the retina - only Osterberg’s  asymmetric array of cones and rods. What on earth is assumed here? How is an image (and ,even further , a color image) formed?  Is there some logic here that is eluding me?

Incidentally, the asymmetric distribution of cones and rods as measured by Osterberg in 1935  forms the exact basis for my explanation of light interaction with the retina and the genesis of color vision. The meaning of this distribution seems to be explained for the first time

A further sentence in the Roorda Letter states that “although the topography of human S cones is known ^{2, 3}…...” (p.520). If this statement were accurate, namely that the so-called S cones have been shown to exist and that they are arranged in some known topography, I would would have to concede that my explanation of the vision process was incorrect.

I  humbly submit, however, that a review of the references cited  ( #2 an #3 as noted above), purportedly that support this contention, do not seem at all to do this!!!!  I stand to be enlightened but this is my reading of the references.

The Williams reference ² is simply inconsistent with their statement. In the reference, and after considerable effort, a single cone receptor is finally located which is defined as an S cone. One might question how this finding can be reconciled with the assertion that a known topography exists. How is one to ascribe a topography to a single cone?

The Curcio reference ³ is even more curious, again,  not at all supporting the statement. This paper relates a much more intensive effort than pursued by Williams to seek the elusive S cone using a number of diverse approaches. But the concluding comment of the paper is most telling stating that “all of the evidence (for the existence of the S cone) must be viewed as inferential only” . The italics are mine but this is the exact term used in the paper. I really do not understand what this means but it is certainly not very positive about the existence of the S cone (or a topography)!

One more note about this piece – as the authors state, their measurements were consistently made “at a retinal eccentricity of one degree nasal from the foveal center”. This region, i.e., at the “edge” of the fovea, is the retinal angle at which there is a greatest interplay of cones and rods – cone density is rapidly diminishing and rods are being introduced into the admixture (again, please take note of the historic data of Osterberg). I would therefore expect to see what R&W imaged at one degree! The pseudocolored images that they present as Figure 3 (p.522) represent exactly what I would expect composed of predominantly red centers representing the long wavelength sensitive cone/cone appositions of the fovea, some number of green centers entering the picture representing the gathering statistical number of cone/rod appositions (and that geometrically define mid band wavelength), and a far fewer number of blue centers characteristic of the, still random at this angle, pairing of rod receptors.

I therefore would agree with the validity of their experimental method recognizing that their measurements were made at one degree of retinal angle. And….these findings at one degree of angle….are in complete consonance with my explanation for light interaction with the retina - and with the long accepted morphology of receptors on the retinal surface.

THERE IS, HOWEVER, ONLY ONE PROBLEM - THE WAVELENGTH DETECTING CENTERS THAT THEY IDENTIFY DO NOT REPRESENT CONES BUT RATHER RECEPTOR APPOSITIONS.

I would propose that if they made a similar type of measurement at 7-8 degrees of retinal eccentricity they would find, accepting that their experimental methodology was correct, that green centers would predominate.

GCH/Ojai,CA

2/29/08

REFERENCES

¹A. Roorda, and D.R.Williams, Nature, 397, No.11, February 1999

² Williams, D.R. et al “Punctate Sensitivity of the Blue Sensitive Mechanism”, Vision Res, 21, 1357-1375, (1981)

³ Curcio, C.A., et al “Distribution and Morphology of Human Cone Photoreceptors Stained with Anti-blue Opsin”, J. Comp. Neurol.,312, 610-624, (1991)

My explanation for light interaction with the retina is that, in contrast with traditional thought, what are actually encoded on this surface are the wavelengths of light that correspond to the longitudinal chromatic aberration of the lens of the eye. Rather than being termed an “aberration” this diffractive wavelength discrimination effect lies at the  core of the vision process.

That the retina is so structured shows clearly that the  the eye – and the resulting vision process –  represent nothing more than a physical embodiment of the well understood physical principles for the diffraction of light.

The retinal surface that evolved to encode these wavelengths can be seen to have been formed using the increasingly understood principles of molecular self-organization. As we enter the era of nanotechnology our knowledge in this field is increasing rapidly. It is fascinating to note that perhaps a seminal experiment in this field was performed by Franklin (the Ben of our founding fathers!) who, intrigued with the spreading of oil films on water surfaces, deduced in the 1700’s the dimensions (unimaginable at the time) of single molecules. We now understand that the basis for this effect is the polarization of oil molecules relative to a water surface causing then to order themselves into monolayers and “self-spread” on the water surface. We now understand a great deal more about these molecular self-ordering effects with perhaps the most important being the nature of polar long chain lipid molecules to form bi-layers that are the ubiquitous membrane of living cells.

There is one more physical phenomenon that must be invoked to illustrate how light shining through that drop of water (the primordial lens of the eye?) formed a lateral molecular structure that spatially encoded different wavelengths of sunlight. Such an effect indeed exists. For a description of this effect see “A Brief History” and the experiments of a number of groups (Dworschak, Young and Siegrist) where the wavelength of a beam of light that is orthogonally incident on a surface is reflected laterally (at right angles, i.e., in the plane of the surface) to form physical structures (optical “gratings”) that have a period that corresponds exactly to the incident wavelength. I propose that this resulting wavelength pattern is “scaffold” to which the self-organizing molecular layers described above conformed.

And then..to get ahead a bit.. nature, as described below, used an elegantly simple geometric scheme to encode the wavelengths of light. It becomes abundantly clear that the eye is not a camera-like “complex design” that both vision science (!) and creationists want to believe.

* I do not want to digress here but it is important to note that the pattern of wavelength detected on the retina that has been chromatically diffracted by the lens of the eye absolutely defines the retina as the Fourier plane of the optics of the eye. The retina then is not the “intensity-only sensitive” image plane that has for so long been erroneously assumed. This has major consequences to understanding the vision process, color perception etc. as I note in the body of the paper

Proceeding to thought about the mechanisms used by the retina to process detected wavelength signals, it is tempting to envision the retina behaving as the analogue of the spectrometer that we commonly use in the laboratory to analyze the composition of light. These devices using prisms, motors etc. possess the capability to decompose a spectrum of light into its constituent wavelengths. Vision science has believed that the retina somehow acts in this manner and then proceeds, again incorrectly, to propose that the initial wavelength detection process leads directly to the sensation of “color”. In attempting to translate the idea of such a “laboratory capability” to the biological realm the concept of pigment molecules contained within retinal receptors has been invoked. This has led to more incorrect notions such as the idea that “classes” of cones exist that are sensitive to the different “colors” even though a great deal of experimental evidence has been accumulated that denies this assertion. When viewed from the perspective of my explanation this seems shallow and irrational reasoning but this has been the thought process in vision science for a hundred years!

But, nature does none of this using a far simpler and elegant geometrical nanostructural construction to form the visual image as I will proceed to explain!

Corroboration of my ideas comes from an unexpected source music theory generating the following text (emphasis is mine):

.”….colour is a matter of relative geometry and not “absolute” chemistry. Land`s discovery was that our brains self-organise to the available wavelengths around a median point - (the “fulcrum”). Further, the same photoreceptor geometries seem to emerge in plants.”

But to set the stage, let’s talk again for a moment about the mechanism for the interaction of light that I described above. This will, perhaps, put this concept in a better prospective for the following discussion. The retina, when viewed from above, is seen to be composed of an array of concentrically arranged light detection centers. These centers can be considered as individual “optical antennas”, that, with the caveat that a quantized region is involved, are loosely analogous to the dipole antennas that we familiarly use in longer wavelength regions of the electromagnetic spectrum. As described above, each center in this nanostructural construction involves a wavelength defining space of variable dimension that is adjacent to a “quantum confined” electron space (or spaces) that are of fixed dimension. One can then go on to envision the retina abstractly as an array of circular spaces of two sizes – t he cones and rods of which we are familiar. I must note that this visualization comprises the entirety of the retinal area containing both the receptor bodies themselves and the inter-receptor medium.

Now the key point – why did nature evolve two sizes (or diameters) of retinal receptors? It can be seen simply that an admixed array of two sizes of circles (as our abstract retina) leads geometrically to three dimensional possibilities. See the “Rosetta Stone” diagram that I have used to express this point.

Rosetta Stone Diagram

Then, fundamental to light detection in the eye, if geometrical lengths correspond to specific optical wavelengths detected as I propose, the retina detects, or is “narrowly tuned to”, three and only three wavelengths. I would propose that this provides the explanation for the early finding  that the vision process is trichromatic.

These three discrete wavelengths detected by the retina have been historically termed the “primary colors”. I believe that they are in fact primary but not yet “colors” reserving that term for the product of the synthesis that the retina (or visual cortex of the brain) performs combining these three primaries into the many hues that we term colors. This would eliminate a great deal of confusion in vision science!

The specific array of receptors on the retinal surface (the historic 1935 data of Osterberg) shows that these three primary wavelengths are detected in circular bands concentrically surrounding the central fovea. Further, it is seen in this explanation that these bands are composed of a variation in density of these primary wavelength detection centers. The wavelength of the interaction has already been determined by diffraction in the eye! Such a density of centers must correlate with the intensity of detected light. Thus, it is the intensity of each primary wavelength that is positionally encoded in the bands on the retinal surface.

As shown in the body of the paper Huth, the all-cone fovea encodes the highest intensity of the “red” primary, the concentric band centered at 7-8 degrees of retinal angle the highest intensity of the “green” primary, and beyond 20 degrees, the highest intensity of the “blue” primary. Nature uses a synthesis of these three intensities of primary wavelengths to arrive at what we see as the many hues of color!

Perhaps the most fundamental result of this explanation is that this geometric coding of “admixture of two sizes” results in an exact central wavelength being geometrically defined on the retinal surface. This would correspond to the 550 nanometer central wavelength of the visible band and is defined by the cone-to-rod dimensionality. The identification of such a fixed wavelength reference on the retinal surface would seem logically to be necessary in any subsequent operation to synthesize color. It is fascinating that Edwin Land in his color experiments deduced the presence on the retina of such a fixed reference! He termed it the “fulcrum” point.

This geometric explanation reveals a number of other avenues to our increased understanding of the vision process. The unique ratio of the two sizes of cone and rod retinal receptors is 1.8:1 and this corresponds to the visual bandwidth (700-400 nanometers). This, in turn, results in the “eight-around-one” octagonal motif of rods-around-cones at 7-8 degrees on the retinal surface. This same octagonal motif is present in the visual organs of many species! Why?

All is geometry!

Thus it can be seen in this progression of ideas that there is no basis for “design”, intelligent or otherwise, in the eye and vision. The eye very simply objectifies the laws of physics (the diffraction of light) and basic geometry. There are still many mysterious aspects to the vision process and these reside in the still largely unknown realm of what constitutes quantum reality. The key here is an explanation for the heretofore unresolved ofthe eye and vision to detect single quanta. Even here this explanation provides clues as to how this comes about. As I have written, I believe that the dividing line between the biological system and the quantum realm is located at the surface of retinal outer segments ! Again, see Huth

GCH

2/4/08