Time-Varying Light Exposure in Chronobiology and Sleep Research Experiments

Spitschan, Manuel

doi:10.3389/fneur.2021.654158

Cited by 10 publications

(12 citation statements)

References 66 publications

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“…Many studies have focused on how these five parameters impact human physiology and whether these could be categorised in terms of higher impact on the acute and circadian responses. 29,[34][35][36][37]…”

Section: Acute and Circadian Responsesmentioning

confidence: 99%

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Investigation of the daylight spectrum in an indoor environment using CIE S 026 melanopic metrics

Englezou,

Michael

2023

Lighting Research & Technology

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Since discovering the intrinsically photosensitive retinal ganglion cells (ipRGCs) and their impact on the circadian rhythm, many disciplines have been researching the physiological and psychological effects of light on humans. However, not much research has been conducted on how the spatial configuration of a room (orientation and gaze direction) changes the light quality and quantity. This research examines the variability of the natural lighting spectrum, focusing on light intensity, the spectrum itself, as well as variations across seasons and hours. The metrics examined are the CIE S 026 melanopic equivalent daylight illuminance (melanopic EDI) and melanopic daylight efficacy ratio (melanopic DER). Field measurements were taken in a room with a south orientation located in Cyprus, using a spectrometer. The main parameters under study were eight gaze directions, four seasons (June, September, December and March) and four different hours each day (09:00, 12:00, 15:00 and 18:00) for 20 positions in the test room. The results show the impact of season, time and gaze direction on the melanopic DER and melanopic EDI. Overall, due to the low sun angle and direct sunlight exposure in the winter, the melanopic EDI was much higher compared to the other three seasons, whereas the melanopic DER had the lowest values. For all seasons and times, most of the cases achieved the minimum recommendation for daytime light exposure of melanopic EDI of more than 250 lx.

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Section: Acute and Circadian Responsesmentioning

confidence: 99%

“…46,47 Person-related variables include chronotype, eye photosensitivities, visual capabilities based on age and history of light exposure. 37,48,49 Finally, variables based on the lighting stimulus should be provided, including the light source, light intensity, timing and duration of exposure and spectral properties. 26,42,43…”

Section: A-opic Metrologymentioning

confidence: 99%

Investigation of the daylight spectrum in an indoor environment using CIE S 026 melanopic metrics

Englezou,

Michael

2023

Lighting Research & Technology

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“…The light stimulus is transmitted through the superior cervical ganglion to the pineal gland via complex neural networks. 8 In this way, light suppresses the synthesis of melatonin, a pineal hormone. The synthesis and release of melatonin is stimulated at night in the dark and suppressed by light during the day.…”

Section: Light Melatonin and Circadian Rhythmmentioning

confidence: 99%

The Effect of Blindness on Biological Rhythms and the Consequences of Circadian Rhythm Disorder

Atan¹,

Subaşı²,

Özdemir³

et al. 2023

tjo

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Various physiological systems and behaviors such as the sleep-wake cycle, vigilance, body temperature, and the secretion of certain hormones are governed by a 24-hour cycle called the circadian system. While there are many external stimuli involved the regulation of circadian rhythm, the most powerful environmental stimulus is the daily light-dark cycle. Blind individuals with no light perception develop circadian desynchrony. This leads to non-24-hour sleep-wake rhythm disorder, which is associated with sleep-wake disorders, as well as mood disorders and loss of appetite and gastrointestinal disturbances due to disrupted circadian hormone regulation. As the diagnosis is often delayed because of under-recognition in clinical practice, patients must cope with varying degrees of social and academic dysfunction. Most blind individuals report that non-24-hour sleep-wake rhythm disorder affects them more than blindness. In the treatment of totally blind patients suffering from non-24-hour sleep-wake rhythm disorder, the first-line management is behavioral approaches. Drug therapy includes melatonin and the melatonin agonist tasimelteon. Diagnosing blind individuals’ sleep disorders is also relevant to treatment because they can be improved with the use of melatonin and its analogues or by phototherapy if they have residual vision. Therefore, assessing sleep problems and planning treatment accordingly for individuals presenting with blindness is an important issue for ophthalmologists to keep in mind.

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“…However, humans are not stationary, moving around in and between different environments that are illuminated by diverse light sources, including electric light, daylight and self-emitting displays such as computer monitors or smartphones, which are themselves not constant due to weather conditions and daylight availability. 18 , 19 Rather than measuring light in a location-specific or source-centric view, there is therefore the need to characterize light exposure in an personalized fashion. 20 Importantly, such characterization is not limited to the physiological “non-visual” responses to light, but can equally include the characterization of the “visual diet”, i.e., which types of colors and illuminances people are exposed to.…”

Section: Introductionmentioning

confidence: 99%

“…As stated earlier, retinal irradiance cannot be practically measured. Even when an observer is stationary and the scene constant, the light effectively reaching the eye and retina will be modulated in time by individual-level characteristics (such as head movements, eyelid closure, facial features, and pupil size 18 , 85 ). Using some assumptions, e.g., a parametric model of pupil size as a function of corneal irradiance, 86 , 87 the retinal irradiance could be reconstructed from corneal irradiance, but not in a spectrally selective way.…”

Section: Introductionmentioning

confidence: 99%

Verification, analytical validation and clinical validation (V3) of wearable dosimeters and light loggers

et al. 2022

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Background Light exposure is an important driver and modulator of human physiology, behavior and overall health, including the biological clock, sleep-wake cycles, mood and alertness. Light can also be used as a directed intervention, e.g., in the form of light therapy in seasonal affective disorder (SAD), jetlag prevention and treatment, or to treat circadian disorders. Recently, a system of quantities and units related to the physiological effects of light was standardized by the International Commission on Illumination (CIE S 026/E:2018). At the same time, biometric monitoring technologies (BioMeTs) to capture personalized light exposure were developed. However, because there are currently no standard approaches to evaluate the digital dosimeters, the need to provide a firm framework for the characterization, calibration, and reporting for these digital sensors is urgent. Objective This article provides such a framework by applying the principles of verification, analytic validation and clinical validation (V3) as a state-of-the-art approach for tools and standards in digital medicine to light dosimetry. Results This article describes opportunities for the use of digital dosimeters for basic research, for monitoring light exposure, and for measuring adherence in both clinical and non-clinical populations to light-based interventions in clinical trials.

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Time-Varying Light Exposure in Chronobiology and Sleep Research Experiments

Cited by 10 publications

References 66 publications

Investigation of the daylight spectrum in an indoor environment using CIE S 026 melanopic metrics

Investigation of the daylight spectrum in an indoor environment using CIE S 026 melanopic metrics

The Effect of Blindness on Biological Rhythms and the Consequences of Circadian Rhythm Disorder

Verification, analytical validation and clinical validation (V3) of wearable dosimeters and light loggers

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