257 How Much Blue Do Blue-Blockers Block if Blue-Blockers Do Block Blue?

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A103-A103
Author(s):  
Brooke Mason ◽  
Andrew Tubbs ◽  
William Killgore ◽  
Fabian-Xosé Fernandez ◽  
Michael Grandner
Keyword(s):  
Light Source ◽  
Blue Light ◽  
Short Wavelength ◽  
Light Exposure ◽  
Visible Spectrum ◽  
Group Differences ◽  
Melatonin Secretion ◽  
Short Wavelength Light ◽  
Wavelength Light ◽  
One Way Anova

Abstract Introduction Short-wavelength light (440-530nm) can suppress endogenous melatonin secretion from the pineal gland. This has been observed in realworld settings when people use electronic media at night that emits light from this part of the visible spectrum. Blue-blocking glasses are a possible intervention to reduce blue light exposure. The present study evaluated the ability of commercially available blue-blockers to block blue light emitted by LEDs. Methods A calibrated spectroradiometer (Ocean Insight), cosine corrector, optic fiber, and software package were used to measure the absolute irradiance (uW/cm^2/nm) generated from a blue light source (Phillips Go Lite Blu) in an otherwise completely dark room. Thirty-one different commercially-available blue-blockers were individually placed between the cosine corrector and the light source at a standardized distance, and then intensity was measured and analyzed. Lenses were evaluated with regards to the amount of blue light they suppressed both individually and grouped by lens tint: red-tinted lenses (RTL), orange-tinted lenses (OTL), orange-tinted lenses with blue reflectivity (OBL), brown-tinted lenses (BTL), yellow-tinted lenses (YTL), and clear lenses with blue reflectivity (RBL). Results RTL blocked 100% of the short-wavelength light, while OTL and OBL blocked 99%, BTL blocked 66%, YTL blocked 38%, and RBL blocked 11% of it. This represented a statistically significant between-group difference (one-way ANOVA, < 0.0001). Within groups, there was variability in performance among individual lenses, though this variability was small compared to the between-group differences. Conclusion The RTL, OTL, and OBL block light best capable of suppressing melatonin secretion at night (440-530 nm); with slightly less efficacy, BTL and YTL also restricted much of the light exposure. Lastly, RBL were not effective at curtailing short-wavelength light. Those looking to optimize blue-blocking capabilities should use RTL, OTL, and OBL, rather than other lens types. Support (if any):

scholarly journals MO SYSTEM USING A SHORT WAVELENGTH LIGHT SOURCE

1995 ◽  
Vol 19 (S_1_MORIS_94) ◽  
pp. S1_295-299 ◽  
Author(s):  
A. FUKUMOTO ◽  
Y. TAKESHITA ◽  
I. ICHIMURA
Keyword(s):  
Light Source ◽  
Short Wavelength ◽  
Short Wavelength Light ◽  
Wavelength Light

255 Spectrophotometric Properties of Commercial Blue-Blocking Lenses in Sunlight

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A102-A103
Author(s):  
Brooke Mason ◽  
Andrew Tubbs ◽  
Fabian-Xosé Fernandez ◽  
Michael Grandner
Keyword(s):  
Group Differences ◽  
Light Sources ◽  
Jet Lag ◽  
Full Spectrum ◽  
Total Light ◽  
Short Wavelength Light ◽  
The Cost ◽  
Dark Signal ◽  
Wavelength Light ◽  
One Way Anova

Abstract Introduction Blue-blocking glasses are increasingly used as an intervention for jet-lag and other situations where an individual wishes to promote a “dark” signal despite the presence of ambient light. However, most studies on blue-blockers are done under controlled laboratory settings using emissions generated from electric light sources. The present study evaluated the performance of commercially available blue-blockers under daytime sunlight conditions. Methods A calibrated spectroradiometer (Ocean Insight), cosine corrector, optic fiber, and software package were used to measure the absolute irradiance (uW/cm^2/nm) available midday in a standardized location that received direct sunlight. Thirty-one commercially available blue-blockers were individually placed in front of the cosine corrector and intensity was measured and analyzed. Each lens was tested for its ability to block visible light, as well as light within the 440-530nm range. Lenses were evaluated individually and grouped by lens type: red-tinted lenses (RTL), orange-tinted lenses (ORL), orange-tinted lenses with blue reflectivity (OBL), brown-tinted lenses (BTL), yellow-tinted lenses (YTL), and clear lenses with blue reflectivity (RBL). Results Across the full spectrum, RTL blocked 66% of the light, OTL blocked 60%, OBL blocked 43%, BTL blocked 56%, YTL blocked 28%, and RBL blocked 20%. When the range was restricted to 440-530nm, RTL blocked 99%, OTL blocked 96%, OBL blocked 90%, BTL blocked 66%, YTL blocked 38%, and RBL blocked 17% of the light. Variation across lens types was significant for the full spectrum (one-way ANOVA, p < 0.0001) as well as the 440-530nm range (one-way ANOVA, p < 0.0001). Individual lenses showed variability in performance, though this variability was smaller than the between-group differences. Conclusion Under daylight conditions, red and orange lenses (RTL, OTL, and OBL) blocked at least 90% of the light in the 440-530nm range. Notably, RBL lenses restricted the most short-wavelength light as a proportion of the total light blocked. These data suggest that RTL, OTL, and OBL are effective at blocking the most circadian photosensitive components of daylight at the cost of reducing total illumination. Support (if any) R01MD011600, R01DA051321

scholarly journals Short-Wavelength Light Enhances Cortisol Awakening Response in Sleep-Restricted Adolescents

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mariana G. Figueiro ◽  
Mark S. Rea
Keyword(s):  
Adrenal Gland ◽  
Short Wavelength ◽  
Light Exposure ◽  
Secondary Analysis ◽  
Cortisol Awakening Response ◽  
Dim Light ◽  
Short Wavelength Light ◽  
The Impact ◽  
Rising Time ◽  
Wavelength Light

Levels of cortisol, a hormone produced by the adrenal gland, follow a daily, 24-hour rhythm with concentrations reaching a minimum in the evening and a peak near rising time. In addition, cortisol levels exhibit a sharp peak in concentration within the first hour after waking; this is known as the cortisol awakening response (CAR). The present study is a secondary analysis of a larger study investigating the impact of short-wavelength(λmax≈470 nm)light on CAR in adolescents who were sleep restricted. The study ran over the course of three overnight sessions, at least one week apart. The experimental sessions differed in terms of the light exposure scenarios experienced during the evening prior to sleeping in the laboratory and during the morning after waking from a 4.5-hour sleep opportunity. Eighteen adolescents aged 12–17 years were exposed to dim light or to 40 lux (0.401 W/m2) of 470-nm peaking light for 80 minutes after awakening. Saliva samples were collected every 20 minutes to assess CAR. Exposure to short-wavelength light in the morning significantly enhanced CAR compared to dim light. Morning exposure to short-wavelength light may be a simple, yet practical way to better prepare adolescents for an active day.

scholarly journals Preliminary Results: The Impact of Smartphone Use and Short-Wavelength Light during the Evening on Circadian Rhythm, Sleep and Alertness

2021 ◽  
Vol 3 (1) ◽  
pp. 66-86
Author(s):  
Christopher Höhn ◽  
Sarah R. Schmid ◽  
Christina P. Plamberger ◽  
Kathrin Bothe ◽  
Monika Angerer ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Blue Light ◽  
Short Wavelength ◽  
Light Filter ◽  
Negative Effects ◽  
Sleep Physiology ◽  
Short Wavelength Light ◽  
Blue Light Filter ◽  
The Impact ◽  
Wavelength Light

Smartphone usage strongly increased in the last decade, especially before bedtime. There is growing evidence that short-wavelength light affects hormonal secretion, thermoregulation, sleep and alertness. Whether blue light filters can attenuate these negative effects is still not clear. Therefore, here, we present preliminary data of 14 male participants (21.93 ± 2.17 years), who spent three nights in the sleep laboratory, reading 90 min either on a smartphone (1) with or (2) without a blue light filter, or (3) on printed material before bedtime. Subjective sleepiness was decreased during reading on a smartphone, but no effects were present on evening objective alertness in a GO/NOGO task. Cortisol was elevated in the morning after reading on the smartphone without a filter, which resulted in a reduced cortisol awakening response. Evening melatonin and nightly vasodilation (i.e., distal-proximal skin temperature gradient) were increased after reading on printed material. Early slow wave sleep/activity and objective alertness in the morning were only reduced after reading without a filter. These results indicate that short-wavelength light affects not only circadian rhythm and evening sleepiness but causes further effects on sleep physiology and alertness in the morning. Using a blue light filter in the evening partially reduces these negative effects.

scholarly journals Effects of an advanced sleep schedule and morning short wavelength light exposure on circadian phase in young adults with late sleep schedules

2011 ◽  
Vol 12 (7) ◽  
pp. 685-692 ◽  
Author(s):  
Katherine M. Sharkey ◽  
Mary A. Carskadon ◽  
Mariana G. Figueiro ◽  
Yong Zhu ◽  
Mark S. Rea
Keyword(s):  
Young Adults ◽  
Short Wavelength ◽  
Light Exposure ◽  
Circadian Phase ◽  
Sleep Schedule ◽  
Short Wavelength Light ◽  
Wavelength Light

258 Blue Blockers’ Ability to Block Circadian-Active Light Emitted from a Tablet

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A103-A104
Author(s):  
Vanessa Bobadilla ◽  
Brooke Mason ◽  
Andrew Tubbs ◽  
Fabian-Xosé Fernandez ◽  
William Killgore ◽  
...  
Keyword(s):  
Electronic Device ◽  
Light Exposure ◽  
Visible Spectrum ◽  
Sleep Cycle ◽  
Full Spectrum ◽  
Blue Range ◽  
Tablet Device ◽  
Short Wavelength Light ◽  
One Way Anova ◽  
Endogenous Melatonin

Abstract Introduction Short-wavelength light emitted from electronic devices in the evening can harm circadian health by suppressing endogenous melatonin and phase-delaying the timing of the wake-sleep cycle. Blue-blocking glasses are one possible intervention to reduce this exposure. The present study evaluated the differential ability of commercially available blue-blockers to filter out the blue range of visible-spectrum light emitted by a common electronic device. Methods A calibrated spectroradiometer (Ocean Insight), cosine corrector, optic fiber, and software package were used to measure the absolute irradiance (uW/cm^2/nm) emitted from a commercially-available computer tablet (iPad) displaying a blank white screen in a closeted dark room. Thirty-one commercially-available blue-blockers were individually placed between the cosine corrector and the tablet. At a standardized distance and angle, the resulting intensity profile was measured and analyzed. Each lens was evaluated individually relative to the light source and then evaluated across subtypes, including red-tinted lenses (RTL), orange-tinted lenses (OTL), orange-tinted lenses with blue reflectivity (OBL), brown-tinted lenses (BTL), yellow-tinted lenses (YTL), and clear reflective blue lenses (RBL). Results There was significant variation in tablet-generated light-blocking across the full spectrum (one-way ANOVA, p < 0.0001) and for the 440-530nm range in particular (one-way ANOVA, p < 0.0001). RTL blocked 99%, OTL blocked 81%, OBL blocked 75%, BTL blocked 83%, YTL blocked 33%, and RBL blocked 17% of broadspectrum light (380-780nm). In the 440nm-530nm range, RTL, OTL, and OBL blocked 100% of the emission, while BTL blocked 81%, YTL blocked 47%, and RBL blocked 18% of it. Conclusion When using a popular tablet device, RTL, OTL and OBL blocked the most circadian photosensitive parts of the light exposure, indicating they can best preserve the timing of endogenous melatonin secretion in the presence of tablet light at night. By contrast, RBL demonstrated very little efficacy. Support (if any) R01MD011600, R01DA051321

scholarly journals No evidence for an S cone contribution to the human circadian response to light

2019 ◽  
Author(s):  
Manuel Spitschan ◽  
Rafael Lazar ◽  
Ebru Yetik ◽  
Christian Cajochen
Keyword(s):  
Retinal Ganglion Cells ◽  
Short Wavelength ◽  
Ganglion Cells ◽  
Light Exposure ◽  
Retinal Ganglion ◽  
Long Wavelength ◽  
Short Wavelength Light ◽  
The Brain ◽  
Wavelength Light

Exposure to even moderately bright, short-wavelength light in the evening can strongly suppress the production of melatonin and can delay our circadian rhythm. These effects are mediated by the retinohypothalamic pathway, connecting a subset of retinal ganglion cells to the circadian pacemaker in the suprachiasmatic nucleus (SCN) in the brain. These retinal ganglion cells directly express the photosensitive protein melanopsin, rendering them intrinsically photosensitive (ipRGCs). But ipRGCs also receive input from the classical photoreceptors — the cones and rods. Here, we examined whether the short-wavelength-sensitive (S) cones contribute to circadian photoreception by using lights which differed exclusively in the amount of S cone excitation by almost two orders of magnitude (ratio 1:83), but not in the excitation of long-wavelength-sensitive (L) and medium-wavelength-sensitive (M) cones, rods, and melanopsin. We find no evidence for a role of S cones in the acute alerting and melatonin supressing response to evening light exposure, pointing to an exclusive role of melanopsin in driving circadian responses.

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