On the Correspondence between the Spectral Sensitivity Characteristics of Human Eye Retina Photo-Receivers and the Frequencies of the Universal Period-Tripling System

The article is devoted to the discussion of the evolutionary adjustment of the photodetectors of the human retina to the frequencies of the UPTS (the so-called universal period-tripling system). This is a new scientific direction in the study of complex systems. The article invites lighting engineers who study the issues of visual perception to get acquainted with the phenomenon of UPTS. To date, an experimental research material has been accumulated and sufficient theoretical grounds have been obtained for the formulation of the assumption that the UPTS and its main parameter Тk, m are manifested in almost all time scales. The values of Тk, m are described with great accuracy by means of the empirical Puetz’s formula. In human vision, UPTS manifests itself in the form of nine periods of Тk, m, corresponding to the cases of m = –11, –8, –5, –3, 0, 3, 5, 8, and 11, where the five central ones dominate –5, –3, 0, 3, and 5, corresponding to the rods, as well as the B- and R-cones. Some questions remain about the G-cones and the ipRGC cells that respond to the extreme, “weakened” values of the index m = –11, –8, 8, and 11. The determination of the proposed calculated values of the wavelengths of light corresponding to the maximum spectral sensitivity of retinal photodetectors is important for specialists in the field of visual perception, medicine, optics, as well as for applications in a number of technical applications.

Retina-like Imaging and Its Applications: A Brief Review

The properties of the human eye retina, including space-variant resolution and gaze characters, provide many advantages for numerous applications that simultaneously require a large field of view, high resolution, and real-time performance. Therefore, retina-like mechanisms and sensors have received considerable attention in recent years. This paper provides a review of state-of-the-art retina-like imaging techniques and applications. First, we introduce the principle and implementing methods, including software and hardware, and describe the comparisons between them. Then, we present typical applications combined with retina-like imaging, including three-dimensional acquisition and reconstruction, target tracking, deep learning, and ghost imaging. Finally, the challenges and outlook are discussed to further study for practical use. The results are beneficial for better understanding retina-like imaging.

Acute Bilateral Blindness in the Setting of Sudden Onset of Bilateral Proptosis and Ophthalmoplegia: A Case Report With Literature Review

ABSTRACTPurposeof review: Acute bilateral blindness has an extensive differential diagnosis that requires a careful history and physical exam to narrow down. In this paper we discuss the pathophysiology and radiographic findings of each possible diagnosis for acute bilateral blindness.Recent findings:Visual pathology with respect to bilateral blindness can be broadly broken down into three anatomic categories: media (i.e. the anterior and posterior chamber of the eye), retina, and neural visual pathway. Possible causes of rapid onset bilateral blindness include bilateral occipital infarcts, endogenous bacterial endophthalmitis, orbital cellulitis, orbital compartment syndrome, cavernous sinus thrombophlebitis, thyroid disease and bilateral non-arteritic ischemic optic neuropathy.Summary:In this case we present a patient with acute onset of bilateral blindness, in addition to bilateral ophthalmoplegia, proptosis, and orbital chemosis. We believe this rare case of acute bilateral blindness is thought provoking and aids in the understanding of the differential diagnosis and underlying pathophysiology of visual loss.

Factors Differentiating the Antioxidant Activity of Macular Xanthophylls in the Human Eye Retina

Macular xanthophylls, which are absorbed from the human diet, accumulate in high concentrations in the human retina, where they efficiently protect against oxidative stress that may lead to retinal damage. In addition, macular xanthophylls are uniquely spatially distributed in the retina. The zeaxanthin concentration (including the lutein metabolite meso-zeaxanthin) is ~9-fold greater than lutein concentration in the central fovea. These numbers do not correlate at all with the dietary intake of xanthophylls, for which there is a dietary zeaxanthin-to-lutein molar ratio of 1:12 to 1:5. The unique spatial distributions of macular xanthophylls—lutein, zeaxanthin, and meso-zeaxanthin—in the retina, which developed during evolution, maximize the protection of the retina provided by these xanthophylls. We will correlate the differences in the spatial distributions of macular xanthophylls with their different antioxidant activities in the retina. Can the major protective function of macular xanthophylls in the retina, namely antioxidant actions, explain their evolutionarily determined, unique spatial distributions? In this review, we will address this question.

Eye Drowsiness Tiredness Detection Based on Driver Experience Using Image Mining

These techniques introduce eye position state and it is parameter as a feasible means of sleepiness recognition. It has been recommended that an increase of eye sleepy state might indicates sleepiness. Thus this method can be used to caution the driver’s risk if driver drives the vehicle. These suggestion were derived from investigative an example of driver’s in attentive and sleepy situation. The gadget evaluate is base on tracking of the eye retina pupil (circular area) to calculate rate of eye sleepy condition. In this research study, individual change in the path of growing sleepiness from a drivers’ eye retina is examined. Data analysis study is interest on the improvement of a prepared display of sleepiness based on an arrangement of eye white and eye black measure values. This will use very accurate operational indicator of drowsiness. However, the main constraint of measure is that driver’s may not show this eye state until they are purely sleepy and/or weaken.

Setting up the Attribute Space of Periodic Time Dependencies for Dynamic Object Diagnostic Systems (Taking the Eye Retina as an Example)

The technology of testing dynamically and structurally similar aircraft models for flutter in subsonic wind tunnels using information and The article addresses techniques for setting up the attribute space of informative features of periodic signals recorded at the output of a dynamic object with an unknown structure in response to rectangular testing signals of different frequencies applied to the object input. The attribute space is used in developing expert systems for diagnosing the current state of an operating dynamic object. With a great variety of possible developing faults, the simplest practical techniques involving the use of characteristic points of change in the observed time dependencies yield a limited number of features with large mutual intersection domains. To expand the attribute space, it is proposed to use the expansion of input and output signals into a Fourier series for setting up a base of additional features. The proposed features characterize, depending on the testing conditions, the object’s transferring properties in the frequency domain from changes in its amplitude and phase characteristics. The test pulse frequency and duration serve as such conditions. For the convenience of comparing the object’s frequency responses variation pattern, two special procedures are used. The first procedure allows the observed time dependencies to be reduced to a single pseudo frequency of the test signals. The second procedure uses specially formed windows for subjecting individual fragments of the observed time dependencies to a spectral analysis. It is shown that, depending on the type of the frequency responses being analyzed, the techniques for their polynomial approximation, as well as integral estimates of frequency response individual domains can be useful. The polynomial approximation makes it possible to use the coefficients of the approximating polynomials as additional features, and the integration of individual characteristic domains of the frequency responses makes it possible to introduce dimensionless relative indicators that characterize the degree of change in the frequency responses depending on the experimental conditions. The considered techniques open the possibility to select additional features that can help distinguish both separate groups of faults and individual faults in operating objects. The study results are illustrated by the examples of analyzing the changes in electroretinograms that record changes in the eye retina biopotential in response to light flashes of different frequencies.

Methods of mathematical modeling of fundus laser exposure for therapeutic effect evaluation

When laser coagulation of eye retina is carried out, the laser beam is directed to target retinal areas selected by an ophthalmologist. The exposure to laser light produces a photocoagulate. When using laser coagulation, the main problem is selecting both the laser exposure areas that would cover all pathological zones and the laser exposure parameters to prevent retina damage. Any patient has an individual fundus structure. The individual structure of pathological and anatomical elements must be taken into account to achieve the desired therapeutic effect. The formation of coagulates in all hemorrhage-affected areas results in the desired therapeutic effect. The vascular layer must be heated to a sufficient temperature to form a coagulate. Such an effect can be predicted using mathematical modeling of laser exposure. In this paper, we consider methods of mathematical modeling of laser exposure based on the solution of a heat equation. The methods are compared in terms of their computational complexity and solution stability. An analysis of the possibility of predicting the therapeutic effect using methods of mathematical modeling of laser exposure is carried out.