scholarly journals The lighting environment, its metrology and non-visual responses

2020 ◽  
Author(s):  
Luc Schlangen ◽  
Luke Price
Keyword(s):  
Ganglion Cells ◽  
Proper Time ◽  
International Workshop ◽  
Spatial Vision ◽  
Light Sensitivity ◽  
Position Statement ◽  
Time Of Day ◽  
Light Sources ◽  
Visual Responses ◽  
Sensitivity Functions

A new international standard, CIE S 026:2018, defines spectral sensitivity functions that describe optical radiation for its ability to stimulate each of the five α-opic retinal photoreceptor classes that contribute, to non-visual effects and functions of light in humans via intrinsically-photosensitive retinal ganglion cells (ipRGCs). The CIE recently published an α-opic toolbox that calculates all the quantities and ratios of the α-opic metrology in the photometric, radiometric and photon systems, either based on a measured (user-defined) spectrum or on selected illuminants (A, D65, E, FL11, LED-B3) built into the toolbox. For most practical ecologically-valid applications, the melanopsin-based photoreception of ipRGCs has been shown to account for the light sensitivity of non-visual responses, from shifting the timing of nocturnal melatonin secretion to regulating steady-state pupil diameter. A CIE position statement recently adopted melanopic EDI in preliminary guidance on using the “proper light at the proper time” to manipulate non-visual responses. Further guidance in this field is expected from an upcoming scientific consensus paper by the participants of the 2nd International Workshop on Circadian and Neurophysiological Photometry (in Manchester, August 2019). Recent findings continue to confirm that melanopsin also plays a role in visual responses. For instance, brightness perception and aspects of spatial vision can be modulated significantly by melanopsin-based photoreception.The new α-opic metrology standardised in CIE S 026 enables traceable measurements for a formal, quantitative specification of personal light exposures and lighting designs. Here, we apply this metrology, together with the toolbox, to everyday light sources including a natural daylight time series, a range of LED lighting products and a smartphone display screen. This collection of examples is of interest to both lighting and public health professions, and suggests ways in which modulations in the melanopic content of light across time of day can be adopted within strategies that use light to support human health and wellbeing.

scholarly journals The Lighting Environment, Its Metrology, and Non-visual Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Luc J. M. Schlangen ◽  
Luke L. A. Price
Keyword(s):  
Spectral Sensitivity ◽  
Ganglion Cells ◽  
Proper Time ◽  
International Workshop ◽  
Spatial Vision ◽  
Well Being ◽  
Position Statement ◽  
Light Sources ◽  
Visual Responses ◽  
Visual Effects

International standard CIE S 026:2018 provides lighting professionals and field researchers in chronobiology with a method to characterize light exposures with respect to non-visual photoreception and responses. This standard defines five spectral sensitivity functions that describe optical radiation for its ability to stimulate each of the five α-opic retinal photoreceptor classes that contribute to the non-visual effects of light in humans via intrinsically-photosensitive retinal ganglion cells (ipRGCs). The CIE also recently published an open-access α-opic toolbox that calculates all the quantities and ratios of the α-opic metrology in the photometric, radiometric and photon systems, based on either a measured (user-defined) spectrum or selected illuminants (A, D65, E, FL11, LED-B3) built into the toolbox. For a wide variety of ecologically-valid conditions, the melanopsin-based photoreception of ipRGCs has been shown to account for the spectral sensitivity of non-visual responses, from shifting the timing of nocturnal sleep and melatonin secretion to regulating steady-state pupil diameter. Recent findings continue to confirm that the photopigment melanopsin also plays a role in visual responses, and that melanopsin-based photoreception may have a significant influence on brightness perception and aspects of spatial vision. Although knowledge concerning the extent to which rods and cones interact with ipRGCs in driving non-visual effects is still growing, a CIE position statement recently used melanopic equivalent daylight (D65) illuminance in preliminary guidance on applying “proper light at the proper time” to manipulate non-visual responses. Further guidance on this approach is awaited from the participants of the 2nd International Workshop on Circadian and Neurophysiological Photometry (in Manchester, August 2019). The new α-opic metrology of CIE S 026 enables traceable measurements and a formal, quantitative specification of personal light exposures, photic interventions and lighting designs. Here, we apply this metrology to everyday light sources including a natural daylight time series, a range of LED lighting products and, using the toobox, to a smartphone display screen. This collection of examples suggests ways in which variations in the melanopic content of light over the day can be adopted in strategies that use light to support human health and well-being.

scholarly journals LIGHTING ENVIRONMENT IN EDUCATIONAL AND MEDICAL INSTITUTIONS: THE PROBLEM OF THE OPTIMAL CHOICE

2018 ◽  
Vol 97 (11) ◽  
pp. 1020-1025
Author(s):  
Valery A. Kaptsov ◽  
V. N. Deynego ◽  
V. N. Ulasyuk
Keyword(s):  
Ganglion Cells ◽  
Light Sensitivity ◽  
Optimal Choice ◽  
Light Environment ◽  
Analytical Models ◽  
Light Sources ◽  
Visual Analyzer ◽  
The Public ◽  
Medical Institutions ◽  
Hormonal System

For the public health, it is essential to determine in what light environment people will develop, live and work in the near future. The present and future of the light environment determine trends in the development of lighting sources. It is important to make a hygienic assessment of the spectra of modern light sources to match the spectrum of the safe sunlight. Trends in the development of led lighting until 2020 and methods of experimental and computer (numerical) modeling of the spectrum of sunlight based on LEDs of various types and their analytical models are considered. The proposed models are shown to allow synthesizing the spectra of led lamps close to sunlight, but they do not meet the requirements of biological adequacy for the human visual analyzer in spectrum width, continuity, uniformity and a set of wavelengths of photon streams that ensure the effective functioning of the human visual analyzer and its hormonal system. The limitations must be taken into account in the development of led lamps by the criterion of root mean square approximation to the spectrum of sunlight and technical implementation to protect the light sensitivity of ganglion cells.

scholarly journals Photoreceptive retinal ganglion cells control the information rate of the optic nerve

2018 ◽  
Vol 115 (50) ◽  
pp. E11817-E11826 ◽  
Author(s):  
Nina Milosavljevic ◽  
Riccardo Storchi ◽  
Cyril G. Eleftheriou ◽  
Andrea Colins ◽  
Rasmus S. Petersen ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Retinal Ganglion Cells ◽  
Information Flow ◽  
Information Transfer ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Ambient Light ◽  
Visual Responses ◽  
Light Irradiance ◽  
The Brain

Information transfer in the brain relies upon energetically expensive spiking activity of neurons. Rates of information flow should therefore be carefully optimized, but mechanisms to control this parameter are poorly understood. We address this deficit in the visual system, where ambient light (irradiance) is predictive of the amount of information reaching the eye and ask whether a neural measure of irradiance can therefore be used to proactively control information flow along the optic nerve. We first show that firing rates for the retina’s output neurons [retinal ganglion cells (RGCs)] scale with irradiance and are positively correlated with rates of information and the gain of visual responses. Irradiance modulates firing in the absence of any other visual signal confirming that this is a genuine response to changing ambient light. Irradiance-driven changes in firing are observed across the population of RGCs (including in both ON and OFF units) but are disrupted in mice lacking melanopsin [the photopigment of irradiance-coding intrinsically photosensitive RGCs (ipRGCs)] and can be induced under steady light exposure by chemogenetic activation of ipRGCs. Artificially elevating firing by chemogenetic excitation of ipRGCs is sufficient to increase information flow by increasing the gain of visual responses, indicating that enhanced firing is a cause of increased information transfer at higher irradiance. Our results establish a retinal circuitry driving changes in RGC firing as an active response to alterations in ambient light to adjust the amount of visual information transmitted to the brain.

scholarly journals Transplanted pluripotent stem cell-derived photoreceptor precursors elicit conventional and unusual light responses in mice with advanced retinal degeneration

2020 ◽  
Author(s):  
Darin Zerti ◽  
Gerrit Hilgen ◽  
Birthe Dorgau ◽  
Joseph Collin ◽  
Marius Ader ◽  
...  
Keyword(s):  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Ganglion Cells ◽  
Light Sensitivity ◽  
Bipolar Cells ◽  
Therapeutic Interventions ◽  
Light Responses ◽  
Motion Sensitivity ◽  
Retinal Dystrophies ◽  
End Stage

SummaryRetinal dystrophies often lead to blindness. Developing therapeutic interventions to restore vision is therefore of paramount importance. Here we demonstrate the ability of pluripotent stem cell-derived cone precursors to engraft and restore light responses in the Pde6brd1 mouse, an end-stage photoreceptor degeneration model. Up to 1.5% of precursors integrated into the host retina, differentiated into cones and formed synapses with bipolar cells. Half of the transplanted mice exhibited visual behaviour and 33% showed binocular light sensitivity. The majority of ganglion cells exhibited contrast-sensitive ON, OFF or ON-OFF light responses and even motion sensitivity. Many cells also exhibited unusual responses (e.g. light-induced suppression), presumably reflecting remodelling of the neural retina. Our data indicate that despite relatively low engraftment yield, engrafted pluripotent stem cell-derived cone precursors can elicit light responsiveness even at advanced degeneration stages. Further work is needed to improve engraftment yield and counteract retinal remodelling to achieve useful clinical applications.

scholarly journals Inverse oculomotor responses of achiasmatic mice expressing a transfer-defective Vax1 mutant

2020 ◽  
Author(s):  
Kwang Wook Min ◽  
Namsuk Kim ◽  
Jae Hoon Lee ◽  
Younghoon Sung ◽  
Museong Kim ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Optic Chiasm ◽  
Stereoscopic Vision ◽  
Retinal Ganglion ◽  
Visual Responses ◽  
Brain Areas ◽  
Optic Stalk ◽  
Intercellular Transfer ◽  
Oculomotor Responses

ABSTRACTIn animals that exhibit stereoscopic visual responses, the axons of retinal ganglion cells (RGCs) connect to brain areas bilaterally by forming a commissure called the optic chiasm (OC). Ventral anterior homeobox 1 (Vax1) contributes to formation of the OC, acting endogenously in optic pathway cells and exogenously in growing RGC axons. Here, we generated Vax1AA/AA mice expressing the Vax1AA mutant, which is selectively incapable of intercellular transfer. We found that RGC axons cannot take up Vax1AA protein from Vax1AA/AA mouse optic stalk (OS) cells, of which maturation is delayed, and fail to access the midline. Consequently, RGC axons of Vax1AA/AA mice connect exclusively to ipsilateral brain areas, resulting in the loss of stereoscopic vision and the inversed oculomotor responses. Together, our study provides physiological evidence for the necessity of intercellular transfer of Vax1 and the importance of the OC in binocular visual responses.

scholarly journals The visual ecology of Holocentridae, a nocturnal coral reef fish family with a deep-sea-like multibank retina

2020 ◽  
pp. jeb.233098
Author(s):  
Fanny de Busserolles ◽  
Fabio Cortesi ◽  
Lily Fogg ◽  
Sara M. Stieb ◽  
Martin Luehrmann ◽  
...  
Keyword(s):  
Visual System ◽  
Reef Fish ◽  
Deep Sea ◽  
Colour Vision ◽  
Ganglion Cells ◽  
Light Sensitivity ◽  
Fish Family ◽  
Visual Systems ◽  
Retinal Topography ◽  
Dim Light

The visual systems of teleost fishes usually match their habitats and lifestyles. Since coral reefs are bright and colourful environments, the visual systems of their diurnal inhabitants have been more extensively studied than those of nocturnal species. In order to fill this knowledge gap, we conducted a detailed investigation of the visual system of the nocturnal reef fish family Holocentridae. Results showed that the visual system of holocentrids is well adapted to their nocturnal lifestyle with a rod-dominated retina. Surprisingly, rods in all species were arranged into 6-17 well-defined banks, a feature most commonly found in deep-sea fishes, that may increase the light sensitivity of the eye and/or allow colour discrimination in dim-light. Holocentrids also have the potential for dichromatic colour vision during the day with the presence of at least two spectrally different cone types: single cones expressing the blue-sensitive SWS2A gene, and double cones expressing one or two green-sensitive RH2 genes. Some differences were observed between the two subfamilies, with Holocentrinae (squirrelfish) having a slightly more developed photopic visual system than Myripristinae (soldierfish). Moreover, retinal topography of both ganglion cells and cone photoreceptors showed specific patterns for each cell type, likely highlighting different visual demands at different times of the day, such as feeding. Overall, their well-developed scotopic visual systems and the ease of catching and maintaining holocentrids in aquaria, make them ideal models to investigate teleost dim-light vision and more particularly shed light on the function of the multibank retina and its potential for dim-light colour vision.

Investigating visual mechanisms underlying scene brightness

2016 ◽  
Vol 49 (1) ◽  
pp. 16-32 ◽  
Author(s):  
UC Besenecker ◽  
JD Bullough
Keyword(s):  
Retinal Ganglion Cells ◽  
Spectral Sensitivity ◽  
Short Wavelength ◽  
Ganglion Cells ◽  
Forced Choice ◽  
Light Sources ◽  
Retinal Ganglion ◽  
Brightness Perception ◽  
Light Levels ◽  
Relative Brightness

Short-wavelength (<500 nm) output of light sources enhances scene brightness perception in the low-to-moderate photopic range. This appears to be partially explained by a contribution from short-wavelength cones. Recent evidence from experiments on humans suggests that intrinsically photosensitive retinal ganglion cells (ipRGCs) containing the photopigment melanopsin might also contribute to spectral sensitivity for scene brightness perception. An experiment was conducted to investigate this possibility at two different light levels, near 10 lx and near 100 lx. Subjects provided forced-choice brightness judgments and relative brightness magnitude judgments when comparing two different amber-coloured stimuli with similar chromaticities. A provisional brightness metric including an ipRGC contribution was able to predict the data with substantially smaller errors than a metric based on cone input only.

Mechanisms and Meaning of Devries—Rose Adaptation

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 39-39
Author(s):  
K Donner ◽  
P Fagerholm
Keyword(s):  
Light Adaptation ◽  
Ganglion Cells ◽  
Statistical Significance ◽  
Quantum Fluctuations ◽  
Luminance Level ◽  
Square Root ◽  
Visual Responses ◽  
Neural Noise ◽  
Visual Cells ◽  
Mean Luminance

‘Square-root’ or ‘deVries — Rose’ light adaptation is observed over a substantial luminance range in human foveal vision. The classical interpretation is that a detector (presumably in the brain) discriminates the neural signal evoked by the stimulus from the neural noise evoked by quantum fluctuations. It is known, however, that the retina may adjust its gain in inverse proportion to the square root of mean luminance, as observed eg in cat retinal ganglion cells under scotopic or mesopic adaptation. This kind of gain change is approximated even by the primary visual cells, the rods and cones, in at least some vertebrate species up to luminances producing 103 – 104 photoisomerisations per photoreceptor cell, per second. Is square-root adaptation in fact mainly an expression of an inverse-square-root gain in retinal cells? We investigated the roles of gain and noise in human foveal detection of 0.25 deg incremental spots presented for 50 ms on 5 deg steady backgrounds ranging from −0.25 to 2.35 log td, by measuring effects of pixel noise added to the stimulus and background. The results were consistent with the hypothesis that square-root adaptation mainly reflects gain changes, whereas the signal is detected against a constant level of neural noise. They were not consistent with the idea that signals proportional to stimulus intensity are detected against a noise that increases in proportion to quantum fluctuations. Thus, they do not support a simple interpretation of the deVries — Rose law. Still, an inverse-square-root retinal gain may in an evolutionary sense be seen as an adaptation to quantum fluctuations, in view of its functional consequences: (1) that output noise stays constant, independent of luminance level; (2) that light signals of constant statistical significance are encoded by visual responses of constant size.

scholarly journals Connections between intrinsically photosensitive retinal ganglion cells and TBI symptoms

Neurology ◽  
2020 ◽  
Vol 95 (18) ◽  
pp. 826-833
Author(s):  
Jason Elenberger ◽  
Bohan Kim ◽  
Alexander de Castro-Abeger ◽  
Tonia S. Rex
Keyword(s):  
Retinal Ganglion Cells ◽  
Sleep Disturbances ◽  
Sleep Problems ◽  
Ganglion Cells ◽  
Light Sensitivity ◽  
Retinal Ganglion ◽  
Root Cause ◽  
Light Sensing ◽  
Pupillary Constriction ◽  
Anxiety Depression

The majority of patients with traumatic brain injury (TBI) are classified as having a mild TBI. Despite being categorized as mild, these individuals report ongoing and complex symptoms, which negatively affect their ability to complete activities of daily living and overall quality of life. Some of the major symptoms include anxiety, depression, sleep problems, headaches, light sensitivity, and difficulty reading. The root cause for these symptoms is under investigation by many in the field. Of interest, several of these symptoms such as headaches, ocular pain, light sensitivity, and sleep disturbances may overlap and share underlying circuitry influenced by the intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells are light sensing, but non–image forming, and they influence corneal function, pupillary constriction, and circadian rhythm. In this review, we discuss these symptoms and propose a role of the ipRGCs as at least one underlying and unifying cause for such symptoms.

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