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Author Alzahrani, H.S.; Khuu, S.K.; Roy, M.
Title Modelling the effect of commercially available blue-blocking lenses on visual and non-visual functions Type Journal Article
Year 2019 Publication (up) Clinical & Experimental Optometry Abbreviated Journal Clin Exp Optom
Volume in press Issue Pages cxo.12959
Keywords Human Health; blue-blocking lenses; non-visual functions; transmittance; visual functions
Abstract BACKGROUND: Blue-blocking lenses (BBLs) are marketed as providing retinal protection from acute and cumulative exposure to blue light over time. The selective reduction in visible wavelengths transmitted through BBLs is known to influence the photosensitivity of retinal photoreceptors, which affects both visual and non-visual functions. This study measured the spectral transmittance of BBLs and evaluated their effect on blue perception, scotopic vision, circadian rhythm, and protection from photochemical retinal damage. METHODS: Seven different types of BBLs from six manufacturers and untinted control lenses with three different powers (+2.00 D, -2.00 D and Plano) were evaluated. The whiteness index of BBLs used in this study was calculated using Commission International de l'Eclairage (CIE) Standard Illuminates D65, and CIE 1964 Standard with a 2 degrees Observer. The protective qualities of BBLs and their effect on blue perception, scotopic vision, and circadian rhythm were evaluated based on their spectral transmittance, which was measured with a Cary 5,000 UV-Vis-NIR spectrophotometer. RESULTS: BBLs were found to reduce blue light (400-500 nm) by 6-43 per cent, providing significant protection from photochemical retinal damage compared to control lenses (p </= 0.05). All BBLs were capable of reducing the perception of blue colours, scotopic sensitivities and circadian sensitivities by 5-36 per cent, 5-24 per cent, and 4-27 per cent, respectively depending on the brand and power of the lens. CONCLUSION: BBLs can provide some protection to the human eye from photochemical retinal damage by reducing a portion of blue light that may affect visual and non-visual performances, such as those critical to scotopic vision, blue perception, and circadian rhythm.
Address School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0816-4622 ISBN Medium
Area Expedition Conference
Notes PMID:31441122 Approved no
Call Number GFZ @ kyba @ Serial 2654
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Author Lowden, A.; Lemos, N.; Gonçalves, B.; Öztürk, G.; Louzada, F.; Pedrazzoli, M.; Moreno, C.
Title Delayed Sleep in Winter Related to Natural Daylight Exposure among Arctic Day Workers Type Journal Article
Year 2018 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 1 Issue 1 Pages 105-116
Keywords Human Health
Abstract Natural daylight exposures in arctic regions vary substantially across seasons. Negative consequences have been observed in self-reports of sleep and daytime functions during the winter but have rarely been studied in detail. The focus of the present study set out to investigate sleep seasonality among indoor workers using objective and subjective measures. Sleep seasonality among daytime office workers (n = 32) in Kiruna (Sweden, 67.86° N, 20.23° E) was studied by comparing the same group of workers in a winter and summer week, including work and days off at the weekend, using actigraphs (motion loggers) and subjective ratings of alertness and mood. Actigraph analyses showed delayed sleep onset of 39 min in winter compared to the corresponding summer week (p < 0.0001) and shorter weekly sleep duration by 12 min (p = 0.0154). A delay of mid-sleep was present in winter at workdays (25 min, p < 0.0001) and more strongly delayed during days off (46 min, p < 0.0001). Sleepiness levels were higher in winter compared to summer (p < 0.05). Increased morning light exposure was associated with earlier mid-sleep (p < 0.001), while increased evening light exposure was associated with delay (p < 0.01). This study confirms earlier work that suggests that lack of natural daylight delays the sleep/wake cycle in a group of indoor workers, despite having access to electric lighting. Photic stimuli resulted in a general advanced sleep/wake rhythm during summer and increased alertness levels.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2137
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Author Prayag, A.; Münch, M.; Aeschbach, D.; Chellappa, S.; Gronfier, C.
Title Light Modulation of Human Clocks, Wake, and Sleep Type Journal Article
Year 2019 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 1 Issue 1 Pages 193-208
Keywords Human Health; Review
Abstract Light, through its non-imaging forming effects, plays a dominant role on a myriad of physiological functions, including the human sleep–wake cycle. The non-image forming effects of light heavily rely on specific properties such as intensity, duration, timing, pattern, and wavelengths. Here, we address how specific properties of light influence sleep and wakefulness in humans through acute effects, e.g., on alertness, and/or effects on the circadian timing system. Of critical relevance, we discuss how different characteristics of light exposure across the 24-h day can lead to changes in sleep–wake timing, sleep propensity, sleep architecture, and sleep and wake electroencephalogram (EEG) power spectra. Ultimately, knowledge on how light affects sleep and wakefulness can improve light settings at home and at the workplace to improve health and well-being and optimize treatments of chronobiological disorders.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2266
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Author Walbeek, T.J.; Harrison, E.M.; Soler, R.R.; Gorman, M.R.
Title Enhanced Circadian Entrainment in Mice and Its Utility under Human Shiftwork Schedules Type Journal Article
Year 2019 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 1 Issue 3 Pages 394-413
Keywords Animals
Abstract The circadian system is generally considered to be incapable of adjusting to rapid changes in sleep/work demands. In shiftworkers this leads to chronic circadian disruption and sleep loss, which together predict underperformance at work and negative health consequences. Two distinct experimental protocols have been proposed to increase circadian flexibility in rodents using dim light at night: rhythm bifurcation and T-cycle (i.e., day length) entrainment. Successful translation of such protocols to human shiftworkers could facilitate alignment of internal time with external demands. To assess entrainment flexibility following bifurcation and exposure to T-cycles, mice in Study 1 were repeatedly phase-shifted. Mice from experimental conditions rapidly phase-shifted their activity, while control mice showed expected transient misalignment. In Study 2 and 3, mice followed a several weeks-long intervention designed to model a modified DuPont or Continental shiftwork schedule, respectively. For both schedules, bifurcation and nocturnal dim lighting reduced circadian misalignment. Together, these studies demonstrate proof of concept that mammalian circadian systems can be rendered sufficiently flexible to adapt to multiple, rapidly changing shiftwork schedules. Flexible adaptation to exotic light-dark cycles likely relies on entrainment mechanisms that are distinct from traditional entrainment.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2661
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Author Papalambrou, A.; Bali, N.
Title Dark Sky Sim: An Open-Design Dark Sky Simulator Type Journal Article
Year 2020 Publication (up) Communicating Astronomy with the Public Abbreviated Journal
Volume 27 Issue Pages 24-26
Keywords Education; Skyglow
Abstract This article describes the key steps on how to construct the Dark Sky Simulator, the outcome of the Dark Sky Sim project. The Dark Sky Simulator is a “physical simulator” to demonstrate the effects of light pollution on the starry sky and the concept of proper lighting. The simulator consists of an LED sky model simulating the starry sky and LED model streetlighting. The simulator creates for users a first-hand experience of light pollution caused by various light fixtures. The simulator was successfully completed, and information on how to construct a simulator with simple tools and inexpensive components are made available online for free. Building the simulator is a very exciting STEM project involving hands-on construction and programming skills in addition to learning astronomy concepts, making it a useful resource for both educational and outreach communities. The project was funded by the International Astronomical Union Office of Astronomy for Development (IAU OAD).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2875
Permanent link to this record