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Huang, Z., Liu, Q., Westland, S., Pointer, M., Luo, M. R., & Xiao, K. (2018). Light dominates colour preference when correlated colour temperature differs. Lighting Research & Technology, 50(7), 995–1012.
Abstract: Colour preference for lighting is generally influenced by three kinds of contextual factors, the light, the object and the observer. In this study, a series of psychophysical experiments were conducted to investigate and compare the effect of certain factors on colour preference, including spectral power distribution of light, lighting application, observers’ personal colour preference, regional cultural difference and gender difference. LED lights with different correlated colour temperatures were used to illuminate a wide selection of objects. Participant response was quantified by a 7-point rating method or a 5-level ranking method. It was found that the preferred illumination for different objects exhibited a similar trend and that the influence of light was significantly stronger than that of other factors. Therefore, we conclude that the light itself (rather than, e.g. the objects that are viewed) is the most crucial factor for predicting which light, among several candidates with different correlated colour temperatures, an observer will prefer. In addition, some of the gamut-based colour quality metrics correlated well with the participants’ response, which corroborates the view that colour preference is strongly influenced by colour saturation. The familiarity of the object affects the ratings for each experiment while the colour of the objects also influences colour preference.
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Lahti, T., Merikanto, I., & Partonen, T. (2012). Circadian clock disruptions and the risk of cancer. Ann Med, 44(8), 847–853.
Abstract: Disrupted circadian rhythms may lead to failures in the control of the cell division cycle and the subsequent malignant cell growth. In order to understand the pathogenesis of cancer more in detail, it is crucial to identify those mechanisms of action which contribute to the loss of control of the cell division cycle. This mini-review focuses on the recent findings concerning the links between the human circadian clock and cancer. Clinical implications concern not only feasible methods for the assessment of the circadian time of an individual or for the determination of the best time for administration of a drug of treatment, but also in the future genetic tests for screening and for planning treatment.
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Landgren, E., Fritsches, K., Brill, R., & Warrant, E. (2014). The visual ecology of a deep-sea fish, the escolar Lepidocybium flavobrunneum (Smith, 1843). Philos Trans R Soc Lond B Biol Sci, 369(1636), 20130039.
Abstract: Escolar (Lepidocybium flavobrunneum, family Gempylidae) are large and darkly coloured deep-sea predatory fish found in the cold depths (more than 200 m) during the day and in warm surface waters at night. They have large eyes and an overall low density of retinal ganglion cells that endow them with a very high optical sensitivity. Escolar have banked retinae comprising six to eight layers of rods to increase the optical path length for maximal absorption of the incoming light. Their retinae possess two main areae of higher ganglion cell density, one in the ventral retina viewing the dorsal world above (with a moderate acuity of 4.6 cycles deg(-1)), and the second in the temporal retina viewing the frontal world ahead. Electrophysiological recordings of the flicker fusion frequency (FFF) in isolated retinas indicate that escolar have slow vision, with maximal FFF at the highest light levels and temperatures (around 9 Hz at 23 degrees C) which fall to 1-2 Hz in dim light or cooler temperatures. Our results suggest that escolar are slowly moving sit-and-wait predators. In dim, warm surface waters at night, their slow vision, moderate dorsal resolution and highly sensitive eyes may allow them to surprise prey from below that are silhouetted in the downwelling light.
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Lawrenson, J. G., Hull, C. C., & Downie, L. E. (2017). The effect of blue-light blocking spectacle lenses on visual performance, macular health and the sleep-wake cycle: a systematic review of the literature. Ophthalmic Physiol Opt, 37(6), 644–654.
Abstract: PURPOSE: Blue-blocking (BB) spectacle lenses, which attenuate short-wavelength light, are being marketed to alleviate eyestrain and discomfort when using digital devices, improve sleep quality and potentially confer protection from retinal phototoxicity. The aim of this review was to investigate the relative benefits and potential harms of these lenses. METHODS: We included randomised controlled trials (RCTs), recruiting adults from the general population, which investigated the effect of BB spectacle lenses on visual performance, symptoms of eyestrain or eye fatigue, changes to macular integrity and subjective sleep quality. We searched MEDLINE, EMBASE, the Cochrane Library and clinical trial registers, until 30 April 2017. Risk of bias was assessed using the Cochrane tool. RESULTS: Three studies (with 136 participants) met our inclusion criteria; these had limitations in study design and/or implementation. One study compared the effect of BB lenses with clear lenses on contrast sensitivity (CS) and colour vision (CV) using a pseudo-RCT crossover design; there was no observed difference between lens types (log CS; Mean Difference (MD) = -0.01 [-0.03, 0.01], CV total error score on 100-hue; MD = 1.30 [-7.84, 10.44]). Another study measured critical fusion frequency (CFF), as a proxy for eye fatigue, on wearers of low and high BB lenses, pre- and post- a two-hour computer task. There was no observed difference between low BB and standard lens groups, but there was a less negative change in CFF between the high and low BB groups (MD = 1.81 [0.57, 3.05]). Both studies compared eyestrain symptoms with Likert scales. There was no evidence of inter-group differences for either low BB (MD = 0.00 [-0.22, 0.22]) or high BB lenses (MD = -0.05 [-0.31, 0.21]), nor evidence of a difference in the proportion of participants showing an improvement in symptoms of eyestrain or eye fatigue. One study reported a small improvement in sleep quality in people with self-reported insomnia after wearing high compared to low-BB lenses (MD = 0.80 [0.17, 1.43]) using a 10-point Likert scale. A study involving normal participants found no observed difference in sleep quality. We found no studies investigating effects on macular structure or function. CONCLUSIONS: We find a lack of high quality evidence to support using BB spectacle lenses for the general population to improve visual performance or sleep quality, alleviate eye fatigue or conserve macular health.
Keywords: Human Health; Vision; Review
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Lee, S., Kakitsuba, N., & Katsuura, T. (2018). Do green-blocking glasses enhance the nonvisual effects of white polychromatic light? J Physiol Anthropol, 37(1), 29.
Abstract: BACKGROUND: It is well known that light containing the blue component stimulates the intrinsically photosensitive retinal ganglion cells (ipRGCs) and plays a role in melatonin suppression and pupillary constriction. In our previous studies, we verified that simultaneous exposure to blue and green light resulted in less pupillary constriction than blue light exposure. Hence, we hypothesized that the nonvisual effects of polychromatic white light might be increased by blocking the green component. Therefore, we conducted an experiment using optical filters that blocked blue or green component and examined the nonvisual effects of these lights on pupillary constriction and electroencephalogram power spectra. METHODS: Ten healthy young males participated in this study. The participant sat on a chair with his eyes facing an integrating sphere. After 10 min of light adaptation, the participant's left eye was exposed to white pulsed light (1000 lx; pulse width 2.5 ms) every 10 s with a blue-blocking glasses, a green-blocking glasses, or control glasses (no lens), and pupillary constriction was measured. Then, after rest for 10 min, the participant was exposed a continuous white light of 1000 lx with a blue- or green-blocking glasses or control glasses and electroencephalogram was measured. RESULTS: Pupillary constriction with the blue-blocking glasses was significantly less than that observed with the green-blocking glasses. Furthermore, pupillary constriction under the green-blocking glasses was significantly greater than that observed with the control glasses. CONCLUSIONS: A reduction in the green component of light facilitated pupillary constriction. Thus, the effects of polychromatic white light containing blue and green components on ipRGCs are apparently increased by removing the green component.
Keywords: Human Health; Vision
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