PROCESSES IN BIOLOGICAL VISION has defined a large and totally new set of performance descriptors applicable to the visual process in all animals. Some of these descriptors provide a new foundation for many of the previously defined empirical descriptors.
These descriptors are placed in several groups below.The transduction and translation processes
A new prototypical form of Vitamin A has appeared as a result of this work. It is Vitamin A3. The three prototypical forms of of Vitamin A are presented on a separate page.
The photosensing process provides the initial excitation of the neural system. It occurs within the photoreceptor cells of the retina. These cells are quite complex. They transform photons into excited electrons and then free electrons that can be processed within an electrolytic circuit domain. Photosensing is divided into two major parts, transduction of the photons into electrons and translation of the initial electrons into a larger stream of electrons.
The TRANSDUCTION PROCESS is the elegant mechanism that creates electrons from photons and provides a significant degree of flexibility as a function of the photon flux absorbed by the individual outer segment of the photoreceptor cell.
The TRANSLATION PROCESS is the elegant mechanism that includes the adaptation amplifier and the distribution amplifier of the photoreceptor cell. It is this mechanism that stabilizes the amplitude of the signals passed to the signal processing neurons of the retina. To aid in this process, the distribution amplifier includes a mechanism for converting the current from the adaptation amplifier to a voltage at the pedicle of the photoreceptor cell.
The ADAPTATION PROCESS is a particularly complex process. It includes both light and dark adaptation and includes time constants that range from about one millisecond to ten minutes. As a result, it is particularly difficult to perform comprehensive experiments on adaptation. Very sophisticated protocols are required to obtain meaningful results.
Before reviewing the following descriptors related to luminosity, it is useful to review the spectral absoprtion characteristics of the chemicals involved in vision, specifically the retinenes and the Rhodonines.
The ABSORPTION CHEMISTRY OF VISION introduces the absorption spectra of the materials important to vision. There has been great confusion in the literature in this area. This page should clarify much of it.
The LUMINOSITY TRANSFER FUNCTION describes the overall phenomena of adaptation and color constancy in vision.
A comparison between the theoretical and empirical LUMINOUS EFFICIENCY FUNCTIONS and the solar radiation spectrum is also available.
The THEORETICAL PHOTOPIC LUMINOUS EFFICIENCY FUNCTION defines the spectral performance of the visual system and shows the CIE Standard to be a convolution of the actual phenomenon and the test instrumentation used.
The THEORETICAL SCOTOPIC LUMINOUS EFFICIENCY FUNCTION defines the spectral performance of the visual system and shows the CIE Standard to be a convolution of the actual phenomenon and the test instrumentation used.
The SPECTRAL THRESHOLD FUNCTION, frequently inappropriately labeled the Luminous Threshold Function, defines the threshold spectral performance of the visual system for various states of adaptation.
The NEW CHROMATICITY DIAGRAM FOR RESEARCH provides a theory based replacement for the conventional empirically based CIE Chromaticity Diagram.
The COMBINED CHROMATICITY AND MUNSELL COLOR DIAGRAM provides a direct link between the spectral aspects of light and the perceived color reported by humans.
The NEW SENSATION DIAGRAM FOR RESEARCH combines the New Chromaticity Diagram for Research (with or without the Munsell Color Space overlay) with the Luminous Scene Intensity to provide a complete theoretical description of the visual sensation space for trichromats.
There are many different transient phenomena known to be associated with human vision. Only selected phenomena will be addressed here.
A NEW DARK ADAPTATION CHARACTERISTIC template provides the theoretical framework underlying the dark adaptation function.
A NEW LIGHT ADAPTATION CHARACTERISTIC template (pending) provides the theoretical framework underlying the light adaptation function.
A variety of common laboratory visual performance experiments can be explained using a suitable model abstracted from the overall model of this work.
The achromatic CONTRAST PERFORMANCE versus TEMPORAL and SPATIAL FREQUENCY functions have been defined for the human visual system in support of the MODELFEST activity in this area.
The more complex chromatic CONTRAST PERFORMANCE versus TEMPORAL and SPATIAL FREQUENCY functions have also been defined for the human visual system in support of the COLORFEST activity in this area. These latter functions are location specific within the color space of vision.
The description of the performance of those with abnormal color vision has been historically difficult because of the lack of a complete nomenclature traceable to an underlying theory. This section begins with nomenclature before presenting proposed new performance descriptors.
A new NOMENCLATURE OF ABNORMAL COLOR VISIONNew descriptors are presented for both what a color abnormal sees and how he is represented on a dual axis Nagel Anomaloscope (Type II).
New CHROMATICITY DIAGRAMS for the color abnormal.
Representation of COLOR ABNORMALS on a NAGEL ANOMALOSCOPE
ACHROMATOPSIA, a severe medical syndrome incorporating the individual symptoms of achromatopia, photophobia, amblyopia and nystagmus.RETURN to the HOME PAGE