Association of time outdoors and patterns of light exposure with myopia in children

2021 ◽  
pp. bjophthalmol-2021-318918
Author(s):  
Mijie Li ◽  
Carla Lanca ◽  
Chuen-Seng Tan ◽  
Li-Lian Foo ◽  
Chen-Hsin Sun ◽  
...  
Keyword(s):  
Light Exposure ◽  
Total Duration ◽  
Growing Up ◽  
Spherical Equivalent ◽  
Outdoor Activities ◽  
Light Levels ◽  
Exposure Patterns ◽  
Activity Diary ◽  
Generalised Estimating Equations ◽  
Multiethnic Children

Background/aimsTo evaluate the association of reported time outdoors and light exposure patterns with myopia among children aged 9 years from the Growing Up in Singapore Towards Healthy Outcomes birth cohort.MethodsWe assessed reported time outdoors (min/day), light exposure patterns and outdoor activities of children aged 9 years (n=483) with a questionnaire, the FitSight watch and a 7-day activity diary. Light levels, the duration, timing and frequency of light exposure were assessed. Cycloplegic spherical equivalent (SE), myopia (SE≤−0.5 D) and axial length (AL) of paired eyes were analysed using generalised estimating equations.ResultsIn this study, 483 (966 eyes) multiethnic children (50.0% boys, 59.8% Chinese, 42.2% myopic) were included. Reported time outdoors (mean±SD) was 100±93 min/day, and average light levels were 458±228 lux. Of the total duration children spent at light levels of ≥1000 lux (37±19 min/day), 76% were spent below 5000 lux. Peak light exposure occurred at mid-day. Children had 1.7±1.0 light exposure episodes/day. Common outdoor activities were walks, neighbourhood play and swimming. Greater reported time outdoors was associated with lower odds of myopia (OR=0.82, 95% CI 0.70 to 0.95/hour increase daily; p=0.009). Light levels, timing and frequency of light exposures were not associated with myopia, SE or AL (p>0.05).ConclusionReported time outdoors, light levels and number of light exposure episodes were low among Singaporean children aged 9 years. Reported time outdoors was protective against myopia but not light levels or specific light measures. A multipronged approach to increase time outdoors is recommended in the combat against the myopia epidemic.

scholarly journals Light Exposure during Days with Night, Outdoor, and Indoor Work

2019 ◽  
Vol 63 (6) ◽  
pp. 651-665 ◽  
Author(s):  
Stine Daugaard ◽  
Jakob Markvart ◽  
Jens Peter Bonde ◽  
Jens Christoffersen ◽  
Anne Helene Garde ◽  
...  
Keyword(s):  
Light Intensity ◽  
Light Exposure ◽  
Spectral Composition ◽  
Working Hours ◽  
Well Being ◽  
Outdoor Workers ◽  
Light Levels ◽  
Light Intensities ◽  
Treatment Of Depression ◽  
Night Shifts

Abstract Objective To assess light exposure during days with indoor, outdoor, and night work and days off work. Methods Light intensity was continuously recorded for 7 days across the year among indoor (n = 170), outdoor (n = 151), and night workers (n = 188) in Denmark (55–56°N) equipped with a personal light recorder. White light intensity, duration above 80, 1000, and 2500 lux, and proportion of red, green, and blue light was depicted by time of the day and season for work days and days off work. Results Indoor workers’ average light exposure only intermittently exceeded 1000 lux during daytime working hours in summer and never in winter. During daytime working hours, most outdoor workers exceeded 2500 lux in summer and 1000 lux in winter. Night workers spent on average 10–50 min >80 lux when working night shifts. During days off work, indoor and night workers were exposed to higher light intensities than during work days and few differences were seen between indoor, outdoor, and night workers. The spectral composition of light was similar for indoor, outdoor, and night workers during days at and off work. Conclusion The night workers of this study were during night hours on average exposed for a limited time to light intensities expected to suppress melatonin. The indoor workers were exposed to light levels during daylight hours that may reduce general well-being and mood, especially in winter. Outdoor workers were during summer daylight hours exposed to light levels comparable to those used for the treatment of depression.

scholarly journals Telling the Seasons Underground: The Circadian Clock and Ambient Temperature Shape Light Exposure and Photoperiodism in a Subterranean Rodent

2021 ◽  
Vol 12 ◽  
Author(s):  
Danilo E. F. L. Flôres ◽  
Milene G. Jannetti ◽  
Giovane C. Improta ◽  
Patricia Tachinardi ◽  
Veronica S. Valentinuzzi ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Laboratory Experiments ◽  
Light Exposure ◽  
Seasonal Patterns ◽  
Subterranean Rodents ◽  
Subterranean Rodent ◽  
Lighting Conditions ◽  
Oscillatory Structure ◽  
Exposure Patterns ◽  
Living Organisms

Living organisms anticipate the seasons by tracking the proportion of light and darkness hours within a day—photoperiod. The limits of photoperiod measurement can be investigated in the subterranean rodents tuco-tucos (Ctenomys aff. knighti), which inhabit dark underground tunnels. Their exposure to light is sporadic and, remarkably, results from their own behavior of surface emergence. Thus, we investigated the endogenous and exogenous regulation of this behavior and its consequences to photoperiod measurement. In the field, animals carrying biologgers displayed seasonal patterns of daily surface emergence, exogenously modulated by temperature. In the laboratory, experiments with constant lighting conditions revealed the endogenous regulation of seasonal activity by the circadian clock, which has a multi-oscillatory structure. Finally, mathematical modeling corroborated that tuco-tuco’s light exposure across the seasons is sufficient for photoperiod encoding. Together, our results elucidate the interrelationship between the circadian clock and temperature in shaping seasonal light exposure patterns that convey photoperiod information in an extreme photic environment.

scholarly journals Light Exposure Patterns in Healthy Older and Young Adults

2010 ◽  
Vol 25 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Karine Scheuermaier ◽  
Alison M. Laffan ◽  
Jeanne F. Duffy
Keyword(s):  
Young Adults ◽  
Light Exposure ◽  
Exposure Patterns

scholarly journals Light exposure patterns and sleep in children

2019 ◽  
Vol 3 ◽  
pp. 170-171
Author(s):  
Huss A ◽  
van Wel L ◽  
Bogaards L ◽  
Vrijkotte T ◽  
Vermeulen R
Keyword(s):  
Light Exposure ◽  
Exposure Patterns

Photobiology of the symbiotic acoel flatworm Symsagittifera roscoffensis: algal symbiont photoacclimation and host photobehaviour

2010 ◽  
Vol 91 (1) ◽  
pp. 163-171 ◽  
Author(s):  
João Serôdio ◽  
Raquel Silva ◽  
João Ezequiel ◽  
Ricardo Calado
Keyword(s):  
Photosynthetic Activity ◽  
Light Exposure ◽  
Light Stress ◽  
Photosynthetic Apparatus ◽  
Light Response ◽  
High Light ◽  
Symbiotic Association ◽  
Light Levels ◽  
Light Gradient ◽  
Custom Made

The symbiotic association between the acoel flatworm Symsagittifera roscoffensis and the prasinophyte microalgae Tetraselmis convolutae was studied regarding its photophysiology and photobehaviour. The photoacclimation status and the photophysiological responses to high light of the algal endosymbiont were studied non-destructively on individual S. roscoffensis using pulse amplitude modulated fluorometry. Specimens collected in an intertidal sandy shore were characterized regarding the maximum quantum yield of photosystem II (PSII), Fv/Fm, and the light response of photosynthetic activity, by constructing rapid light-response curves of the relative electron transport rate of PSII, rETR. The studied population could be considered as high light-acclimated when compared with other intertidal photosynthetic organisms (e.g. macroalgae), with the light-saturation parameter Ek averaging 250 μmol m−2 s−1. Light stress experiments showed S. roscoffensis to be able to withstand the exposure to high light without displaying signs of photoinhibition, suggesting the operation of efficient physiological photoprotective processes. The photobehaviour of S. roscoffensis was studied by characterizing the distribution of the flatworms under a light gradient, using a custom-made photoaccumulation chamber. The results showed a photoaccumulation pattern evidencing a clear avoidance of extreme low or high light levels, and with maximum photoaccumulation values being found for a range of irradiances (150–400 μmol m−2 s−1) that generally coincided with the optima for photosynthetic activity. This matching between the optimum light levels for photosynthetic activity and photoaccumulation suggested that S. roscoffensis may use vertical migration as a form of behavioural photoprotection. This behavioural response may be used to rapidly and flexibly control light exposure, avoiding photodamage to the endosymbiont photosynthetic apparatus by direct exposure to sunlight.

Luminous Exposures and Light-Fastness Survey in Daylit Historical Museum Galleries under Tropical Sky Conditions

2012 ◽  
Vol 488-489 ◽  
pp. 1547-1552 ◽  
Author(s):  
Noraini Ahmad ◽  
Sabarinah Sh Ahmad ◽  
Anuar Talib
Keyword(s):  
Light Exposure ◽  
Light Fastness ◽  
Preventive Conservation ◽  
Light Levels ◽  
Data Loggers ◽  
Architectural Features ◽  
Colour Changes ◽  
Sky Conditions ◽  
The Impact ◽  
Exposure Measurements

This paper highlights the results of light levels and light-fastness study conducted in four daylit historical museum galleries in Malaysia. These museums architectural features allow sun radiation into the building, causing light exposure damage to artifacts. This study aims to evaluate the luminous exposures and light-fastness as an initial preventive conservation measure in daylit historical museum galleries under the tropical sky conditions. Light sensors with data-loggers and Light-fastness dosimeters were installed throughout the museums to take cumulative light exposure measurements during museum opening hours. Both instrumentations were tested in the field during different campaigns exposures. After exposures between 90 and 100 days, these dosimeters showed photo-induced colour changes which translated exposures into equivalent luminous exposure and estimated annual exposures (Lux hours) which were used to validate the measured values of illuminance data. Simulated light dosimeters and measured illuminance data show good correlation. Thus, equivalent light dosimeter makes sense to assess the impact of light distributions.

scholarly journals Epidemiology characteristics for non-myopic Chinese children aged 6 to 12 years in Jiangsu Province

2019 ◽  
Author(s):  
Xiyan Zhang ◽  
Yonglin Zhou ◽  
Jie Yang ◽  
Yan Wang ◽  
Wenyi Yang ◽  
...  
Keyword(s):  
Early Warning ◽  
Jiangsu Province ◽  
Chinese Children ◽  
Spherical Equivalent ◽  
Demographic Information ◽  
Outdoor Activities ◽  
Ophthalmic Examination ◽  
The Mean ◽  
Near Work ◽  
Aged Eleven

Abstract Background: We aimed to present epidemiology characteristics including SE value, age, BMI, sex for non-myopic Chinese children after indicating the prevalence of myopia among children aged six to twelve . Based on these we were trying to develop alert values for predicting the future onset of myopia. Methods: All students took part in the ophthalmic examination filled in a questionnaire to provide basic demographic information. We used an autorefractor applying with cycloplegia to obtain spherical equivalent value, and part of their parents filled in a questionnaire of factors related to myopic among children. Results: We finally had 3900 non-myopic observations from 6362 students, and the prevalence of myopia is 38.0% for boys and 39.5% for girls respectively. The average values for SE were 0.5±0.7 for boys and 0.6±0.8 for girls respectively. The mean SE decreased with age in children, and the value of height and BMI took on a stable trend. Alert values for myopia could be set as follows, for children aged six years of age, 0.4-0.6 D for boys and 0.8-1.0 D for girls respectively. For children aged seven years of age, 0.4-0.6 D for boys and 0.3-0.5 D for girls respectively, for children aged eight years, 0.2-0.4 D for boys and 0.3-0.5D for girls, for children aged nine years, 0.2-0.4 D for boys and 0.3-0.4D for girls, 0.1-0.3 D for boys aged ten and 0.3D for girls aged ten years, 0.10-0.3 D for boys aged eleven and -0.3-0.3 D for girls aged eleven years, and for children aged twelve ,-0.1-0.1 D for boys and -0.3-0.1 D for girls aged twelve years. Father’s myopia ( OR:1.22,95%CI:1.01-1.48 ), near work on weekends (OR:2.56,95%CI:1.17-5.61) and outdoor activities (OR:0.68,95%CI:0.54-0.86) had an impact to non-myopic students with myopic alerting. Conclusion: Our study presented an epidemiology description for non-myopic students in Jiangsu Province, and we proposed a series of alert values to provide early warning reference for Chinese children aged six to twelve years. We draw a nomograph to predict the probability of myopia onset and found that family, near work and outdoor activities, had an impact on non-myopic students with myopic alerting.

scholarly journals Night-to-Night Associations Between Light Exposure and Sleep Health

2021 ◽  
Author(s):  
Michael Mead ◽  
Kathryn Reid ◽  
Kristen Knutson
Keyword(s):  
Sleep Duration ◽  
Light Exposure ◽  
Poor Sleep ◽  
Sleep Health ◽  
Cross Sectional ◽  
Wake Time ◽  
Light Levels ◽  
Fragmentation Index ◽  
Multi Level ◽  
Offset Time

Previous research has demonstrated that exposure to light preceding and during sleep is associated with poor sleep, but most research to date has utilized either experimental or cross-sectional designs. The current study expands upon prior studies by using a microlongitudinal design that examines the night-to-night associations between light and sleep health in a diverse sample of adults (pre-registered at osf.io/k5zgv). U.S. adults aged 18 to 87 from two parent studies (N= 124) wore an actiwatch for up to 10 nights. Light variables estimated from actigraphy include both average exposure and time above light threshold of 10 (TALT10) and 40 (TALT40) lux both during sleep and for the 1-hour preceding sleep. Actigraphy-based sleep variables included sleep offset, duration, percentage, and fragmentation index. Higher average light exposure during sleep was associated with a later sleep offset time, lower sleep percentage, and higher fragmentation index (all p <.01). More minutes of TALT10 during sleep was associated with later sleep timing, lower sleep percentage, and higher fragmentation index (all p < .01) and greater TALT40 during sleep was associated with lower sleep percentage. Light exposure was not related to sleep duration. In summary, greater light exposure during sleep was related to poorer sleep continuity and later wake time. The lack of association between light and sleep duration may be the result of compensating for sleep disruption by delaying wake time. Multi-level interventions to consistently reduce light levels during sleep should be considered.

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