Blue-light Blocking Research Articles

Synthesis and application of poly methyl indole-4-carboxylate with blue light blocking properties

Blue light hazards have garnered increasing attention owing to the popularity of displays. Although melanin on the retina acts as a blue light barrier, overexposure to blue light increases the risk of visual damage. A class of methyl indole-n-carboxylate oligomers (O-MInC, n = 3, 4, 5, 6, and 7) was synthesized through solid-phase oxidative polymerization. Based on the experimental characterizations, including time-of-flight mass spectrometry, infrared spectroscopy, and density functional theory calculations of the average local ionization energy, we proposed a mechanism for the oxidative polymerization of methyl indole-4-carboxylate (MI4C). Methyl indole-4-carboxylate oligomer (O-MI4C) is composed of cyclic oligomers containing large conjugated structures that are generated by the repetition of electron deprivation, radical coupling, and dehydrogenation reactions. O-MI4C exhibits the best blue light absorption among its allotropes substituted at different positions with a cut-off absorption wavelength of 530 nm. Finally, O-MI4C was added to polymethylmethacrylate (PMMA) and Columbia resin 39 (CR-39) flakes through in situ polymerization to investigate the behavior of blue light blocking. The PMMA/O-MI4C (0.01 wt%) and CR-39/O-MI4C (0.02 wt%) can block 25% and 35% of blue light; however, they have no significant effect on green and orange lights.

Blue LED light exposure induces metabolic rewiring in vitreous tissues in rat models

Blue light exposure induced retinal damage has been extensively studied. Retinal damages are closely associated with cellular and biochemical changes occurring in the vitreous and hence, understanding metabolic changes in vitreous tissue might serve as clinical importance to indicate ocular/vision health. In the present study, we have investigated the influence of blue light-emitting diodes (LED) on the vitreous metabolome and further, we show amelioration of altered metabolite levels upon blue light blocking lenses (BBLs). A total of n = 24 (n = 6 in each group; control, light exposure without lenses, two different BBLs) male Wistar rats were subjected to blue light exposure (LEDs, 450–500 lx) without or with BBLs (400–490 nm) for 28 days on a 12:12 h light–dark cycle. Post-exposure the vitreous fluid aspirated was subjected for untargeted liquid chromatography/mass spectrometry-based metabolomics analysis. Analyzed vitreous revealed blue light significantly modulated metabolites such as Tyrosine, L-Histidine (p = 0.02), L-Isoleucine (p = 0.007), Valine (p = 0.04) and D-Proline (P < 0.001) along with affected homocysteine degradation and nitric oxide signalling pathway. Our findings suggest exposure to blue LED poses a significant hazard to the vitreous as it alters thevitreousmetabolites, and it is partially ameliorated by commercially available BBLs.

Blue light-blocking efficiency of blue light-blocking and driving spectacle lenses

Background: Retinal damage caused by blue light can result in glare, decreased visual acuity, and accelerated macular degeneration. In clinical practice, blue light-blocking glasses, such as driving glasses, are used to block blue light effectively. This study was aimed at measuring light transmittance to analyze the blue light-blocking efficiencies of blue light-blocking and driving spectacle lenses manufactured with tinting, coating, and only materials and at distinguishing the difference between the two spectacle lenses.&#x0D; &#x0D; Methods: Blue light-blocking and driving spectacle lenses used to measure light transmittance were manufactured with tinting (blue light blocking lenses by tinting or “BTL” and driving spectacle lenses by tinting or “DTL,” respectively), coating (blue light blocking lenses by coating or “BCL” and driving spectacle lenses by coating or “DCL,” respectively), and only materials (blue light blocking lenses by material or “BML” and driving spectacle lenses by material or “DML,” respectively).&#x0D; &#x0D; Results: Compared to BTL, DTL had a significantly greater decrease in the light transmission efficiency for visible and blue lights (P &lt; 0.05). The blue light hazard function was lower for BML and DML than for conventional coating lenses in both visible and blue lights, although without significant differences between visible and blue lights (P &gt; 0.05).&#x0D; &#x0D; Conclusions: The blue light-blocking spectacle lenses had the highest blue light-blocking efficiency when manufactured with tinting, coating, and only materials, in order. With DML, the blue light-blocking efficiency was lower compared to DTL but higher compared to DCL. Therefore, DML could provide a balanced glare control and clear retinal image overall.

Blue Light Blocking Treatment for the Treatment of Bipolar Disorder: Directions for Research and Practice.

Recent results from a small number of clinical studies have resulted in the suggestion that the process of blocking the transmission of shorter-wavelength light (‘blue light’ with a wave length of 450 nm to 470 nm) may have a beneficial role in the treatment of bipolar disorder. This critical review will appraise the quality of evidence so far as to these claims, assess the neurobiology that could be implicated in the underlying processes while introducing a common set of research criteria for the field.

Seeking eye protection from biomass: Carbon dot-based optical blocking films with adjustable levels of blue light blocking

The intensity of blue light in white light emitting diodes is typically higher than that of the green and red-light components in screen displays and lighting systems. To reduce the potential harm of in white light emitting diodes to the eyes, in this paper, we have used microcrystalline cellulose to synthesize biomass-based carbon dots (Bio-CD), which not only absorb short wavelength light to produce longer wavelength emissions, but also show concentration-dependent maximum excitation and maximum emission. The Bio-CDs were mixed with polyvinyl alcohol (PVA) to produce optical blocking films (OBF) that preferentially block blue light. OBFs have good transparency and also block blue light effectively. With OBFs containing 9.9% of Bio-CDs, the film blocked 99.6% and 98.6% of 395 nm light and 450 nm light respectively, and also blocked 93.4% and 97%, respectively, of the blue light emitted by computers and mobile phone screens. OBFs containing more than 9.9% Bio-CDs block blue light more than commercially available blue light blocking glasses. By adjusting the amount of Bio-CDs in the OBFs, it is possible to produce films with different degrees of blue light blocking to meet the requirements of different applications.

Findings from a systematic review of fatigue interventions: What's (not) being tested in mining and other industrial environments.

Fatigue negatively impacts mineworker health and safety. In this paper, we identify fatigue interventions tested on industrial shiftworkers and explore their effects and the factors that may influence application in an industrial setting such as a mine site. This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. A structured, systematic search of the literature was conducted to identify relevant studies published between 1980 and 2020. Researchers independently conducted article screening and study quality appraisals against pre-established criteria, and then extracted data and conducted a narrative synthesis of the included studies. Seven intervention studies, out of 1651 articles initially screened, were retained for narrative synthesis. Four studies tested the alerting effects of bright-light treatment, one evaluated the effectiveness of blue-light blocking glasses at improving daytime sleep quality and nighttime vigilance, and two examined whether sleep hygiene and alertness management trainings improved sleep quality or alertness. There was substantial evidence for the use of bright-light treatments to improve night shiftworker alertness, but insufficient evidence to draw conclusions about the effectiveness of blue-light blocking glasses and sleep hygiene and alertness management trainings due to the small number of studies included. Shiftworkers were mostly male and employed in industrial subsectors such as production and manufacturing, oil and gas, and transportation. No mining-specific intervention studies were identified. Future research is needed to identify effective fatigue risk management interventions for the mining industry as well as best practices for implementing these interventions with mineworkers.

Blue Light-Induced Retinal Neuronal Injury and Amelioration by Commercially Available Blue Light-Blocking Lenses.

Blue light exposure-induced retinal damage has been extensively studied. Although many in vitro studies have shown the benefits of blue light-blocking lenses (BBL) there have been few comprehensive in vivo studies to assess the effects of BBL. We investigated the influence of blue light exposure using light-emitting diodes on retinal histology and visual cortex neurons in rodents. We also considered whether retinal and cortical changes induced by blue light could be ameliorated with blue light-blocking lenses. A total of n = 24 (n = 6 in each group; control, light exposure without lenses, two different BBLs)) male Wistar rats were subjected to blue light exposure (LEDs, 450–500 lux) without or with BBLs (400–490 nm) for 28 days on a 12:12 h light–dark cycle. Histological analysis of retinae revealed apoptosis and necrosis of the retinal pigment epithelium (RPE), photoreceptors, and inner retina in the light exposure (LE) group, along with increase caspase-3 immunostaining in the ganglion cell layer (p < 0.001). BBL groups showed less caspase-3 immunostaining compared with the LE group (p < 0.001). V1-L5PNs (primary visual cortex layer 5 pyramidal neurons) demonstrated reduced branching and intersections points for apical (p < 0.001) and basal (p < 0.05) dendrites following blue light exposure. Blue light-blocking lenses significantly improved the number of basal branching points compared with the LE group. Our study shows that prolonged exposure to high levels of blue light pose a significant hazard to the visual system resulting in damage to the retina with the associated remodeling of visual cortex neurons. BBL may offer moderate protection against exposure to high levels of blue light.

Marshalling the senses for a good night's sleep: Multiple studies have linked poor sleep to cancer and other negative health outcomes; in part 1 of a 2-part series, we explore how efforts to improve sleep patterns are focusing on aligning multiples senses and on correcting misconceptions: Multiple studies have linked poor sleep to cancer and other negative health outcomes; in

Marshalling the senses for a good night's sleep: Multiple studies have linked poor sleep to cancer and other negative health outcomes; in part 1 of a 2-part series, we explore how efforts to improve sleep patterns are focusing on aligning multiples senses and on correcting misconceptions: Multiple studies have linked poor sleep to cancer and other negative health outcomes; in

Blue-light-blocking Lenses in Eyeglasses: A Question of Timing.

Blue-light-blocking Lenses in Eyeglasses: A Question of Timing.

Effects of pre-bedtime blue-light exposure on ratio of deep sleep in healthy young men

This study aimed to investigate the effects of pre-bedtime blue-light exposure on ratio of deep sleep and sleep quality. In this study, 11 healthy young men were exposed to three conditions for 1 h before bedtime: 1) incandescent light, 2) blue-light, or 3) blue light-blocking glasses on. The following morning, subjective sleep quality was measured using the Oguri–Shirakawa–Azumi Sleep Inventory. Sleep time, ratio of sleep, ratio of deep sleep, and body movements during sleep were measured using a mat sleep-scan (sleep scan, SL- 504; TANITA Corp., Japan) and an ambulatory portable sleep study system (LS-140; Fukuda Denshi Co. Ltd., Japan). Ratio of deep sleep was significantly decreased in the blue-light exposure group compared to the groups with incandescent light and blue light-blocking glasses (p < 0.01), There were no differences noted in sleep time or body movements among the three groups. These results suggest that blue-light exposure to affects sleep quality by reducing the ratio of deep sleep.

291 A Pilot Study of Light Management in the US Navy

Abstract Introduction Exposure to light at appropriate times can improve alertness and mood; however, light can also interfere with sleep if exposure occurs before bedtime. Therefore, light management is important for sailor well-being and operational performance. One approach to administer light in field settings is to use personal wearable devices. This pilot study assessed the challenges in using the blue-light blocking goggles (BLBG) and light emitting goggles (LEG) for crewmembers of a US Navy ship while underway. Methods Longitudinal (~2 weeks) assessment of sailors (N=18) during deployment. Sailors completed a questionnaire asking whether they used the devices, reasons (if any) they may have had for not using the devices, what they liked/did not like about the devices, and whether wearing the devices made a difference in terms of fatigue, alertness, ability to fall asleep, and reported sleep quality. Results Sailors reported that the LEGs seemed to increase alertness (n=8) and helped wake up faster (n=5), but the devices were bulky/heavy (n=9), too bright (n=4), and made it difficult to see in dim light (n=2). The reported reasons for not using the devices include: the devices were heavy/uncomfortable (n=5), they caused eye strain (n=4), and the LEGs interfered with sailor ability to see while on watch (n=3). Also, wearing the LEGs made sailors feel less tired (71%) and more alert (59%). Sailors reported that the BLBGs kept them drowsy before bed (n=3) and reduced eye strain (n=5). Sailors complained, however, that BLBGs were bulky/inconvenient (n=3). When not wearing the BLBGs, it was because the devices were easy to forget (n=2), sailors had to work after their shift (n=2), and other reasons (n=3). Wearing the BLBGs during watch made falling asleep easier (47%) and improved sleep quality (47%). Conclusion This study provided valuable insight regarding the use of personal wearable light management devices in field settings. Even though not conclusive, our results are promising. We will continue assessing the utility of such devices with a goal of improving sailor well-being and operational performance. Support (if any) Supported by the Naval Medical Research Center’s Advanced Medical Development Program, the US Navy 21st Century Sailor Office, and the US Navy OPNAV N1.

A Study on Factors Affecting the Effect of Blue Light Blocking in Sunscreen

A Study on Factors Affecting the Effect of Blue Light Blocking in Sunscreen

Effect of evening blue light blocking glasses on subjective and objective sleep in healthy adults: A randomized control trial

ObjectivesEvening blue light has been shown to suppress melatonin, which can negatively impact sleep quality. The impact of evening blue light blocking (BLB) interventions on sleep remains ambiguous due to lack of randomized control trials. The present study tests the hypothesis that BLB glasses improve subjective and objective sleep in a population of healthy adults. DesignTwo-week, randomized, controlled, crossover design. SettingAt-home testing of individuals in Michigan and Montana. ParticipantsTwenty healthy adults (11 men, 9 women, age: 32 ± 12, body mass index: 28 ± 4 kg/m2). InterventionFollowing a 1-week run-in baseline (ie, no glasses), participants were randomized to 1-week of BLB or control (ie, clear lens) glasses. Upon finishing the 1-week intervention, participants crossed over to the opposite condition. In both conditions, glasses were worn for 7 consecutive days from 6 PM until bedtime. MeasurementsObjective sleep parameters were obtained using wrist actigraphy. Subjective sleep measures were assessed using sleep diaries. Karolinska Sleep Diaries were used to assess perceived sleep quality. ResultsBLB reduced subjective sleep onset (21 ± 28 vs 24 ± 21 minute, P = .033) and awakenings (1.6 ± 1.0 vs 2.2 ± 1.0 awakenings, P = .019) compared to the control condition. In contrast, objective measures of sleep were not significantly impacted. In fact, our primary outcome variable of total sleep time (TST) tended to be paradoxically shorter in the BLB condition for both subjective (468 ± 45 vs 480 ± 48 minute, P = .066) and objective (433 ± 40 vs 449 ± 39 minute, P = .075) TST. ConclusionsBlue light blocking glasses did not improve objective measures of sleep time or quality in healthy adults.

Convergence study of comparison of blue light blocking rate between colored lenses of various colors and dental tips

Convergence study of comparison of blue light blocking rate between colored lenses of various colors and dental tips

A Study on the Manufacturing of Blue Light Blocking Hydrogel Contact Lenses Using Benzotriazole Derivatives

Purpose : The purposes of this study are to synthesize benzotriazole derivatives for the development of blue light blocking hydrogel contact lenses and to investigate their optical and physical properties. Methods : After benzotriazole, which acts as a blue light blocking compound, was synthesized, blue light blocking hydrogel contact lenses were made by the copolymerizing benzotriazole derivatives, HEMA, and EGDMA monomers in the presence of initiator AIBN. The water content, optical properties, blue light blocking rate and ultraviolet light blocking rate of the manufactured lenses were investigated.Results : The blue and ultraviolet light blocking performance of the manufactured lenses were superior to that of the unmodified control. It was shown that as the density of benzotriazole derivatives increases, the blue and ultraviolet light blocking rate of the resulting lenses are improved. Water content showed no significant difference compared to that of the unmodified control. Conclusion : Manufactured blue light blocking contact lenses can provide a strategy for the development of the contact lenses which are excellent in blue and ultraviolet light blocking performance without deteriorating the physical properties of conventional contact lenses.

Synthesizing of Blue-light Blocking Polymeric Materials and Manufacturing Contact Lenses

Purpose : Blue-light blocking polymers were synthesized and interpenetrated into the hydrogel contact lenses. The water contents and blue-light blocking properties of the resultant contact lenses with varying amounts of the blue-light blocking polymers were investigated and compared to that of the unmodified control.Methods : Polyethyleneimine (PEI) was covalently conjugated with blue-light adsorbing reactive dyes (Procion Yellow MX8G) via a nucleophilic substitution reaction and incorporated into the hydrogel contact lenses. The blue-light blocking properties of the hydrogel lenses were investigated using UV-vis spectrophotometry.Results : The blue-light adsorbing reactive dyes were successfully conjugated to the PEI and well incorporated into the hydrogel contact lenses. The resultant contact lenses exhibited good blue-light blocking properties according to the results of the UV-vis spectra investigation. Furthermore, we confirmed that the blue-light adsorbing dyes were not eluted from the contact lenses after extensive washings for 3 days.Conclusion : This report describes the synthesis and characterization of a series of hydrogel contact lenses containing blue-light blocking polymers. The hydrogel contact lenses showed good water contents and a transmittance of over 90% in the range of 450~700 nm. In particular, the blue-light blocking properties at the range of 380~450 nm were enhanced significantly as the increment in the amount of incorporated blue-light blocking polymers. The preparation of blue-light-blocking contact lenses may offer a new opportunity for the development of biomedical ophthalmic devices.

Ortho-Benzoquinone을 기반으로 하는 청색광 차단 수화젤 콘택트렌즈 제조

ortho-Benzoquinone을 기반으로 하는 청색광 차단 수화젤 콘택트렌즈 제조

코팅 청색광 차단 렌즈의 제작과 특성 연구

코팅 청색광 차단 렌즈의 제작과 특성 연구

Long-Term Reduction of Short-Wavelength Light Affects Sustained Attention and Visuospatial Working Memory With No Evidence for a Change in Circadian Rhythmicity.

The short wavelength, i.e., blue light, is crucial for non-image forming effects such as entrainment of the circadian system in humans. Moreover, many studies showed that blue light enhances alertness and performance in cognitive tasks. However, most scientific reports in this topic are based on experiments using short exposure to blue or blue-enriched light, and only a few focused on the effects of its reduced transmittance, especially in longer periods. The latter could potentially give insight into understanding if age-related sleep problems and cognitive decline are related to less amount of blue light reaching the retina, as the eyes’ lenses yellow with age. In this study, we investigated the effects of prolonged blocking of blue light on cognitive functioning, in particular—sustained attention and visuospatial working memory, as well as on sleep, and melatonin and cortisol levels. A group of young, healthy participants was randomly allocated to either blue light blocking or control group. Depending on the group, participants wore amber contact lenses, reducing the transmittance of blue light by ∼90% or regular contact lenses for a period of 4 weeks. No changes were observed for measurements related to sleep and sleep–wake rhythm. Dim light melatonin onset, evening levels of melatonin, and morning cortisol answer did not show any significant alterations during blue light (BL) blockade. The significant effects were revealed both for sustained attention and visuospatial memory, i.e., the longer blocking the blue light lasted, the greater decrease in performance observed. Additionally, the follow-up session conducted ∼1 week after taking off the blue-blocking lenses revealed that in case of sustained attention, this detrimental effect of blocking BL is fully reversible. Our findings provide evidence that prolonged reduction of BL exposure directly affects human cognitive functioning regardless of circadian rhythmicity.

Analysis on the Light Transmittance of Blue-Light Blocking Lenses by Manufacturing Methods

Purpose : This study was to analyze the characteristics of the blue light blocking lens manufactured by the material method currently used in clinical practice, by measuring its light transmittance. Methods : The conventional coating lens (CCL) and the material type blue light block lens (BML) with refractive index of 1.56, 1.60, and 1.67 and the coating type blue light blocking lens (BCLa, BCLb) and tinting type blue light blocking lens (BTL) with refractive index of 1.60 were collected respectively to measure the light transmittance. A back vertex refractive power of all the lenses was 0.00 D. Results : Both light transmittance and distribution area of BML first decreased, the started to increase as refractive index increased, but no significant difference was found(p＞0.050). BML’s efficiency in blue light blocking was higher than CCL but lower than the others with different manufacturing types including BTL, BCLa, and BCLb. Conclusion : Before recommending the blue light lens with material method, precise consulting is required to comprehend a subject’s individual condition while wearing.