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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 Clinical & Experimental Optometry Abbreviated Journal Clin Exp Optom
Volume in press Issue (up) Pages
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 Rahman, S.A.; St Hilaire, M.A.; Lockley, S.W.
Title The effects of spectral tuning of evening ambient light on melatonin suppression, alertness and sleep Type Journal Article
Year 2017 Publication Physiology & Behavior Abbreviated Journal Physiol Behav
Volume 177 Issue (up) Pages 221-229
Keywords Human Health
Abstract We compared the effects of bedroom-intensity light from a standard fluorescent and a blue- (i.e., short-wavelength) depleted LED source on melatonin suppression, alertness, and sleep. Sixteen healthy participants (8 females) completed a 4-day inpatient study. Participants were exposed to blue-depleted circadian-sensitive (C-LED) light and a standard fluorescent light (FL, 4100K) of equal illuminance (50lx) for 8h prior to a fixed bedtime on two separate days in a within-subject, randomized, cross-over design. Each light exposure day was preceded by a dim light (<3lx) control at the same time 24h earlier. Compared to the FL condition, control-adjusted melatonin suppression was significantly reduced. Although subjective sleepiness was not different between the two light conditions, auditory reaction times were significantly slower under C-LED conditions compared to FL 30min prior to bedtime. EEG-based correlates of alertness corroborated the reduced alertness under C-LED conditions as shown by significantly increased EEG spectral power in the delta-theta (0.5-8.0Hz) bands under C-LED as compared to FL exposure. There was no significant difference in total sleep time (TST), sleep efficiency (SE%), and slow-wave activity (SWA) between the two conditions. Unlike melatonin suppression and alertness, a significant order effect was observed on all three sleep variables, however. Individuals who received C-LED first and then FL had increased TST, SE% and SWA averaged across both nights compared to individuals who received FL first and then C-LED. These data show that the spectral characteristics of light can be fine-tuned to attenuate non-visual responses to light in humans.
Address Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, United States; Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States; Division of Sleep and Circadian Disorders, Department of Neurology, Brigham and Women's Hospital, Boston, MA 02115, United States
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 0031-9384 ISBN Medium
Area Expedition Conference
Notes PMID:28472667 Approved no
Call Number LoNNe @ kyba @ Serial 1659
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Author Russart, K.L.G.; Nelson, R.J.
Title Light at night as an environmental endocrine disruptor Type Journal Article
Year 2018 Publication Physiology & Behavior Abbreviated Journal Physiol Behav
Volume 190 Issue (up) Pages 82-89
Keywords Human Health; Animals
Abstract Environmental endocrine disruptors (EEDs) are often consequences of human activity; however, the effects of EEDs are not limited to humans. A primary focus over the past approximately 30years has been on chemical EEDs, but the repercussions of non-chemical EEDs, such as artificial light at night (LAN), are of increasing interest. The sensitivity of the circadian system to light and the influence of circadian organization on overall physiology and behavior make the system a target for disruption with widespread effects. Indeed, there is increasing evidence for a role of LAN in human health, including disruption of circadian regulation and melatonin signaling, metabolic dysregulation, cancer risk, and disruption of other hormonally-driven systems. These effects are not limited to humans; domesticated animals as well as wildlife are also exposed to LAN, and at risk for disrupted circadian rhythms. Here, we review data that support the role of LAN as an endocrine disruptor in humans to be considered in treatments and lifestyle suggestions. We also present the effects of LAN in other animals, and discuss the potential for ecosystem-wide effects of artificial LAN. This can inform decisions in agricultural practices and urban lighting decisions to avoid unintended outcomes.
Address Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
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 0031-9384 ISBN Medium
Area Expedition Conference
Notes PMID:28870443 Approved no
Call Number LoNNe @ kyba @ Serial 1719
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Author Souman, J.L.; Tinga, A.M.; Te Pas, S.F.; van Ee, R.; Vlaskamp, B.N.S.
Title Acute alerting effects of light: a systematic literature review Type Journal Article
Year 2018 Publication Behavioural Brain Research Abbreviated Journal Behav Brain Res
Volume 337 Issue (up) Pages 228-239
Keywords Human Health
Abstract Periodic, well timed exposure to light is important for our health and wellbeing. Light, in particular in the blue part of the spectrum, is thought to affect alertness both indirectly, by modifying circadian rhythms, and directly, giving rise to acute effects. We performed a systematic review of empirical studies on direct, acute effects of light on alertness to evaluate the reliability of these effects and to assess to what extent they depend on other factors, such as time of day, exposure duration and sleep pressure. In total, we identified 74 studies in which either light intensity, spectral distribution, or both were manipulated, and the effects on behavioral measures of alertness were evaluated, either subjectively or measured in performance tasks. The results show that increasing the intensity or the color temperature of polychromatic white light in general has been found to increase subjective ratings of alertness, though a substantial proportion of these studies failed to find significant effects. There is little evidence in the literature that these subjective alerting effects of light also translate into improvements on performance measures of alertness. For monochromatic or narrowband light exposure, some studies have shown improvement in reaction time tasks with exposure to blue light, but generally this was not accompanied by changes in subjective alertness. Thus, the alerting effects of light are far less clear than often suggested. We suggest that in future studies more attention should be paid to other factors that may influence the effects of light, such as chronotype, circadian phase, homeostatic state and prior light history.
Address Philips Research (Department Brain, Behavior & Cognition), Eindhoven, The Netherlands
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 0166-4328 ISBN Medium
Area Expedition Conference
Notes PMID:28912014 Approved no
Call Number LoNNe @ kyba @ Serial 1727
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Author Willis, G.L.; Freelance, C.B.
Title The effect of directed photic stimulation of the pineal on experimental Parkinson's disease Type Journal Article
Year 2017 Publication Physiology & Behavior Abbreviated Journal Physiol Behav
Volume 182 Issue (up) Pages 1-9
Keywords Animals
Abstract The role of the circadian system in Parkinson's disease (PD) is a topic of increasing scientific interest. This has emerged from recent studies demonstrating an altered response of PD patients to treatment in relation to the phase of the light/dark cycle and from other work defining the functional significance of melanocytes in PD: a cell type that the nigro-striatal dopamine (NSD) system and circadian system both contain. The present study was undertaken to determine the sensitivity of the pineal, as the final common pathway of the circadian system, to light delivered directly to the pineal via surgical implantation of LEDs. Direct photic stimulation of the pineal altered the course of experimental PD while anatomical controls receiving stimulation of the frontal cortex exhibited a negative impact on the course of recovery of these animals. These effects were closely linked to the phase of the light/dark cycle. The present results suggest that while pineal photoreceptors are regarded as vestigial, functional photo-reactivity of the pineal remains. It is inferred that melanocytes are the active cells responsible for the observed effect since they remain functionally intact in mammalian pineal even though pineal photoreceptors are functionally inert. Although the stimuli applied in the present study may be regarded as artificial this study demonstrates that brain parenchyma remains differentially reactive to direct light exposure and presents a novel mechanism in circadian structures that needs to be explored.
Address The Bronowski Institute of Behavioural Neuroscience, Coliban Medical Centre, 19 Jennings Street, Kyneton, Victoria 3444, 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 0031-9384 ISBN Medium
Area Expedition Conference
Notes PMID:28919247 Approved no
Call Number LoNNe @ kyba @ Serial 1732
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