Rethinking the Process of Vision

The light detection centers of the retina are “geometrically tuned” (as in spatial “antennas”) to three precise wavelengths. It is crucial to note that the detection of these wavelengths at the point of the receptor outer segments does not yet constitute the sensation of the hues of color. I propose that the historical shortcut that terms  detection of these three singular wavelengths as “colors” has led to a totally incorrect view of the vision process.

Following from the concept of  “antennas” it should be obvious that the eye evolved to detect the wave of classical physics and not particle photons as is generally (and incorrectly) assumed.

The cone/cone appositions (i.e., the “center-to-center distance) in the fovea geometrically define the precise long wavelength limit of the visual band.  The cone/rod appositions that begin at the edge of the fovea and peak in number at 8-9 degrees of retinal angle define the precise, again geometrically-determined, center of the visual band. At larger retinal angles comprising the peripheral retina , rod/rod appositions define the, again precise, short wavelength limit of vision.

(it will  be obvious to those inclined to physics that the retina is structured as a diffractive surface and forms the Fourier or focal plane of the eye. The eye is not a camera! Each antenna/spatial light detection center possesses the ability to detect both the intensity and phase of light as required by the Fourier equation. I have proposed the retinal structure that accomplishes this in the main body of the paper)

The detection of these wavelengths at the plane of receptor outer segments occurs in the near field of the light wave and in very fast femtosecond time). At thiis point they are still “only wavelengths”.

As brilliantly shown by Edwin Land the sensation of the hues of color are then synthesized from what Land termed “lightnesses” (related to light intensities) on either side of the exact geometrically determined mid band wavelength (that this explanation defines!. It is only then that the term “primary colors” can be used.

The three wavelengths initially detected on the retina were always “primary” but not yet “color” !

How misleading this shortcut has been in the history of vision.

GCH
Ojai, CA
9.21.09

I can certainly go no further than to make the phenomenological observation the transition from electromagnetic wave to quantized particle occurs at light detecting sites on the retina of the eye. I believe that the proper terminology to describe the light interaction event should be that a “quantized interaction” occurs on the retinal surface and not the traditional construction that a “photon interacts….with a pigment molecule”.

In contradiction to historical assumptions, I find that the eye evolved to detect light as the wave of classical physics with the absorbed energy assuming the form of an  electron particle that serves subsequent electrical signaling and image processing functions.

Further, and what has been confounding in past assumptions, is that the initial light interaction at individual  sites on the retina (that I define) lies within the near field of the light wave, i.e., within spatial dimensions smaller than the wavelength of light (approximately one micron),. This, in turn implies that the initial defining interaction occurs in the time domain approximating femtoseconds (or 10-15 seconds). These assumptions finally explain the ability of the eye to accomplish the feat of discerning single light photons (or, as defined above, “single quantized interactions”)at body temperature.

There is a significant amount of modern experimental results (thoroughly referenced in the body of the work) that supports this explanation. These include recent experimental results showing that light travels outside of optical fibers that are smaller in diameter than light wavelength and the long known experimental result that the signal-forming isomerization of the retinal molecule (within the rhodopsin structural protein complex) occurs in femtosecond time. These results taken together support this new explanation.

I must emphasize that all of the foregoing applies to the initial  light interaction at the plane of the outer segments of each individual retinal center. The electron particle that results is actually “thermalized” in the absorption process for subsequent use in the biochemical processes of the remainder of the retina . I believe that  thermalization follows from the transit of the absorbed energy along the length of the membrane of each thylakoid disk that forms the length of the receptor outer segment.

The traditionally taught  model that that the eye functions as a “camera” in slow time of  the order of  milliseconds (10-3 second) must be abandoned.

The future of vision research is inexorably bound up with the considerations and evolution of quantum physics.

A note:

I believe that seminal thoughts in this regard are contained in a recently published paper by Engel et al of the University of California at Berkeley.
(Evidence for Wavelike Energy Transfer Through Quantum Coherence in Photosynthetic Systems”).This group using new femtosecond spectroscopy  observes quantum coherence (or “quantum wave-like” behavior) within the near field of light and in femtosecond time. I must add that I have proposed and written that the same light interaction mechanism of this work explains the extraordinarily high light detection efficiency of photosynthesis as well as the ability of the eye to see single quanta.

Written on a quiet Sunday morning in Tucson, AZ !

GCH
9.13.09

Reading Pirenne’s Vision and the Eye (published by Chapman and Hall Ltd. 1948), chapter 16, Theory of Color Vision, where it can be almost pinpointed where the science of vision took a wrong turn.

From the section: Vision of the Trichromat on p.179,   following the previous and  correct insights of Young, Helmholtz et al describing  the trichromicity of visual response:

“In the case of trichromat vision the situation is more complicated, but it can be said with logical certainty that the trichromats must possess at least three kinds of cones…….”.

(I am reminded here of a comment made years ago by a friend of mine about a colleague of his that “he was the most logical individual he had ever known but he was invariably wrong!)

I propose that the “logical certainty” argument of the statement arrives at an erroneous conclusion -    it is not three kinds of light detecting “cones”, but really three kinds of  light detection “centers”. In this work these centers are shown to be receptor appositions and not the cone or rod receptors themselves…..with, further, the organization of these centers demonstrating that the retina is a diffractive surface……..further still indicating clearly that the retina forms the Fourier (or focal) plane of the optics of the eye…….and on.

Light does not interact within receptors but between adjacent receptors.

The protein opsin within the receptors themselves plays a structural role in holding the retinal molecule - that is ubiquitous to all receptors  - in the three (cone/cone, cone/rod, and rod/rod) light-accepting conformations.

Each of these individual light detection centers functions in what is termed the “near field” of  light wavelength, i.e., in the spatial domain less than one micron. (in the fiberoptics analogy this means that light  travels on the outside of a receptor/fiber)

In turn, the speed of the light detection process is extremely fast - in the femtosecond (or 10-15 sec)  time domain.

There can be no doubt that the eye evolved to detect (interact with) the wave nature of light.

It was never that “photons…interact with pigments within receptors etc.) and the ensuing, nonsensical, “photon catch” hypothesis!

The process of quantization of light is effected at each of the hundreds of millions of light detection sites on the retina  where the light wave is translated into a quantized electron particle.

The retina is a truly unique nanostructural array!

GCH
9.05.09

I believe that historically these two terms have come to be misused  in the field of vision with dire consequences to an understanding of the vision process.

To wit:

1. As described in this work, the retina of the eye evolved to interact with the electromagnetic radiation that we term “light” as a wave and not, as historically assumed, as “photons interacting with pigment molecules within receptors”. Although the visual band is described as extending from 400 to 700 nanometers we need not  at all be concerned with these numbers! The retina has been evolutionarily “tuned” following the principles of this work, to only three narrow wavelengths that define the precise endpoints, and, importantly to what follows, the exact middle of this band. We need not concern ourselves with any “laboratory numbers”- nature employs pure geometry to determine these values. This view is in consonance with, and is the basis for,  the accepted “trichromicity” of vision that was correctly deduced long ago by Young. BUT….following this correct deduction, it was imagined that there were three “primary” (that much is correct - they are “primary”)) but then followed by the term “colors” to which the retina was supposedly sensitive. IT IS CRUCIAL THAT IT BEEN SEEN THAT AT THIS POINT ON THE RETINA THIS IS NOT YET COLOR!

2. In the broadest sense,  we should realize that the sensation that we have come to know as “color” (that might more properly be understood as  “the many hues of color”) must be differentiated from the three narrow “primary  wavelengths” that the retina detects - that  at this point have not yet been synthesized into “colors”. Moreover, it becomes clear from this work that the geometrical basis for light interaction (summarized above) finally explains how the sensation of  color  (”the hues of color”) is  synthesized and  validates the prescient work of Edwin Land!  Land, without any knowledge of of this geometric model of light interaction on the retina, reasoned that, what he termed a “fulcrum”, existed somewhere in the vision process that divided the visual band. It is now known that this fulcrum dividing point is determined by the geometrically defined mid-band (I will use numbers - 550 nanometers) centers corresponding to cone-to-rod appositions. Land found that (again the “sensation” of ) color, was determined by  the eye determining a ratio of  what he termed “lightnesses” (roughly light intensities) on either side of this defined fulcrum on the retina. It becomes clearer that Edwin Land was the true genius of vision science! Differentiate the three primary wavelengths that the retina detects and the following synthesis of the sensation of color

Respectfully submitted,

GCH Ojai, CA 9.03.09