Rethinking the Process of Vision

I have been off on other things but this idea needs mentioning. I earnestly solicit the thinking of others in developing the following thoughts.

My view of light interaction with the retina seems in coincidence with a holographic explanation of the vision process.

Quoting from Cathey (Optical Information Processing and Holography, Wiley Interscience):

“ the hologram has the properties of a lens except that the wave is intercepted and stored before being allowed to continue its propagation to form an image.”

It is well understood that holographic information is stored as both intensity and phase defined by the Fourier equation.  This exactly represents my description of light interaction with the retina of the eye. The intensity and phase of light are detected (and processed) at each inter-receptor (“antenna”) light interaction element of the retina.

What caught my attention from Cathey  (p.58) was the statement:

 “Gabor also considered only the case where the illuminating wave also serves as a reference wave”.

This quote is from Gabor’s  first publication describing holography in a Letter to Nature in 1948 http://www.nature.com/physics/looking-back/gabor/gabor.pdf . I would note the utter simplicity of the paper. Who would have prediced  the massive technology that has emerged from this simple exposition!

It had always been my understanding (never having thought in depth about it!) that a second “reference wave” was necessary to “read” a hologram.

Again from Cathey (p.58):

“Holograms can be recorded without the reference wave being introduced at an angle to the wave from the object. This, in fact, was the manner in which Gabor (see reference) made the first hologram. In making this hologram, a transparent object was used (a transparency with dark lettering) allowing the non-diffracted portion of the wave to serve as a reference wave for the information-bearing portion diffracted by the lettering.”

What startled me was that Gabor used a portion of the axially incident beam as a reference wavelength to read a hologram (the first hologram!). See his Figure 1 that illustrates this. He did not use an external wavelength reference beam.

There are many factors that enter here including coherence of wavelengths etc. but might not the eye use this principle?

I have stopped in my explanation at the point where light interacts with retinal outer segments and I have described how individual retinal inter-receptor “devices”  are capable of detecting both the intensity and phase of incident light noting that this means that the retina forms the Fourier and not the intensity-only sensitive image plane of the optics of the eye,  

I have not gone into how the visual image is subsequently processed other than noting that detection of the phase of incident light implies knowledge about direction and that this must ultimately be involved in formation of the visual image.

I have also assigned a role to the peripheral retina of acting as a large area “light meter” that functions to control pupillary constriction and overall light level into the eye.

Perhaps, however, the peripheral retina might reflect (antennas radiate as well as detect) a “reference” wavelength back into the beam of  image-forming RGB wavelengths that interact at relatively narrow angles from the fovea to about 20 degrees.  ???  Such an interaction would occur in the time domain of light interaction or about 10^-15 seconds.

The question will be asked: does the eye possess the capability necessary  to process the vast information content of a hologram.

Following from my explanation – it does.

I have written that the vision field  has been in error in seeing the “reaction time of the eye” as being in the millisecond  (10^-3 sec) time domain. Even my friend Albert Rose reported this error.  This is the reaction time of the human nervous system subsequent to retinal interaction  and not the time domain of light interaction with the retina that has  been experimentally determined to be in the femtosecond  (10^-15 sec) region.

There is most certainly sufficient bandwidth in this fast time region to entertain the idea that the vastly increased information content flowing from the eye exists necessary to entertain the idea of a holographic concept.

Further I would add that these thoughts should provide insight into the realm of neuroscience. That field seems to accept the slow time / low information content that has traditionally been assumed.

Obviously, these are very preliminary thoughts. I welcome the ideas of others.

GCH

Ojai, Ca