A review of the current state of research on artificial blue light safety as it applies to digital devices

Computer vision syndrome: a comprehensive literature review

Computer Vision Syndrome is a growing health concern in the digital age, with a reported prevalence of 69.0%. It is caused by screen-related, environmental, ergonomic, and physiological factors, affecting diverse demographics. The COVID-19 pandemic significantly amplified CVS due to increased screen time for remote work, online learning, and social media use, with studies reporting symptoms in up to 74% of individuals. Unique visual challenges from digital screens, including reduced clarity and glare, exacerbate symptoms like dry eyes and discomfort, especially in those with uncorrected vision. Understanding CVS is crucial for mitigating its impact through effective prevention and management strategies. This study explores the causes, diagnosis, management, and prevention strategies of CVS by synthesizing recent findings from optometry, occupational health, digital health, and ergonomics. It also highlights emerging trends such as AI, wearables, and augmented reality while providing practical management strategies. A narrative review of literature from 2014 to 2024 was conducted, focusing on PubMed-indexed, peer-reviewed articles, including meta-analyses and systematic reviews, with priority given to recent, highly cited studies.

Preclinical Toxicological Assessment of 2-(Benzoxazol-2-yl)[(2-hydroxynaphthyl)diazenyl]phenol Derivatives for Blue Light and UV Radiation Photoprotection Applications

The widespread use of electronic devices has led to increased blue light exposure, highlighting the need for effective radiation blockers with blue light protection. Two synthetic 2-(2'-hydroxyphenyl)benzoxazole derivatives named azo-4'-benzoxazole and azo-5'-benzoxazole have shown an unprecedented blue light absorption capacity but had not been subjected to a safety evaluation. This study aimed to evaluate the cytotoxic, genotoxic, and mutagenic activities of these compounds. The cytotoxic and genotoxic activities were evaluated using MTT assay and comet assay in L929 fibroblast cells. Salmonella/microsome assay and micronucleus test were performed to detect gene and chromosomal mutations. The IC50 was 87.9 μg/mL for azo-4'-benzoxazole and 79.5 μg/mL for azo-5'-benzoxazole. In the Salmonella/microsome assay, the azo-5'-benzoxazole compound induced frameshift mutations in the TA97a strain in the presence of metabolic activation (S9 mix), while azo-4'-benzoxazole did not show mutagenic activities in all five strains tested. The azo-5'-benzoxazole showed genotoxic and mutagenic effects in L929 cells that were probably associated to the cleavage of azo-5' into its analogs 2-(4'-amino-2'-hydroxyphenyl)benzoxazole and 2-amino-1-naphthol. In conclusion, the azo-substituted group at the 5' position of the phenyl ring appears to have greater toxicological risks than substituents at the 4' position of 2-(phenyl)benzoxazole. The findings warrant further preclinical studies to ensure the safety of these compounds for use as blue light filters.

Blue Light Irradiation Elicits Senescence of Corneal Endothelial Cells In Vitro by Provoking Energy Crisis, Inflammasome Assembly and DNA Damage

PURPOSE

The blue light from the digital screens endangers the visual system among which the corneas at the outmost of eyes are vulnerable to the irradiation. Therein, the human corneal endothelial (HCE) cells are crucial to maintain corneal transparency and their damage leads to HCE decompensation resulting in blindness ultimately. Thus, understanding the phototoxic effects of the blue light on the HCE cells and the underlying mechanisms is important for taking measures to protect the vision clarity from the blue-light hazard.

METHODS

We pulse-irradiated the HCE cell line cells at logarithmic phase for 3 passages using 440 nm blue light and examined the levels of reactive oxygen species (ROS), ATP, nicotinamide adenine dinucleotide (NAD+) and autophagy using cytochemistry assay to investigate the alterations of energy metabolism. Moreover, we examined the γH2AX+ cells using immunofluorescence and expression of poly(ADP-Ribose)polymerase1 (PARP1) using western blotting to investigate the degrees of DNA damage and repair. We also monitored the levels of inflammasome using western blotting and senescence associated secretory phenotypes (SASPs) of interleukin (IL)-8, IL-1β and IL-6 using qPCR and ELISA to investigate the inflammasome assembly and secretion of SASPs. We detected the senescent features with senescence-associated-β-galactosidase assay, p16 levels by western blotting, Lamin B1 localization by immunofluorescence observation, cell growth by EdU incorporation assay and confluence forming time and alterations of the cell morphology and relative areas by microscopy observation.

RESULTS

The HCE cells exhibited senescent features after blue-light-pulse-irradiation. The blue light provokes overproduction of ROS to decrease the levels of ATP, NAD+ and autophagy leading to energy crisis. Moreover, the excess ROS injure DNA and downregulate PARP1 resulting in stable cell-cycle arrest. The excess ROS also facilitate inflammasome assembly leading to hypersecretion of SASPs.

CONCLUSION

The blue light elicits HCE cell senescence via inducing energy crisis, stable cell-cycle arrest and SASP hypersecretion.

Screening for Sleep Disturbances in Children and Adolescents with Tics, Headache Disorders or Type 1 Diabetes

Sleep is essential for mental and physical well-being, yet it is often overlooked in children with medical conditions. To address this gap, we implemented screening for sleep disturbances to assess their prevalence in our clinics and identify potential intervention strategies. This cross-sectional study included children and adolescents aged 6-17 years with tics/Tourette syndrome, headaches, type 1 diabetes, and a healthy control group, who completed the validated Sleep Screening Questionnaire-Children and Adolescents (SSQ-CA).In total, 157 children with medical conditions and 117 healthy children completed the Sleep Screening Questionnaire-Children and Adolescents. Overall, 81.5% of the children with medical conditions reported a sleep disturbance compared with 70.9% in the healthy group (P = .28). Those with medical conditions reported poorer sleep quality (P < .001) and more awakenings (P = .047), as well as more frequent use of mobile/computer (P = .001) and television (P = .002) before bedtime compared with healthy children.We identified an alarmingly high prevalence of sleep disturbances in children with selected medical conditions, including more use of screens before bedtime, highlighting a significant yet frequently overlooked issue and possible target for intervention.

Dual-Functional Carbon Dot Films: Blue-Light Filtration and Cyan-Light Conversion for Healthier White Light-Emitting Diodes

Blue light emitted by commercial white light-emitting diodes (WLEDs) in the 440-470 nm range poses ocular health risks with prolonged exposure. Effective filtration is crucial for health-conscious lighting, but traditional filters often cause color distortion by completely removing blue emission. In this study, we address this challenge by synthesizing carbon dots (CDs) with strong absorption at 460 nm and bright cyan emission at 485 nm, featuring a photoluminescence quantum yield of 65% and a narrow full width at half-maximum of 30 nm. When embedded in a poly(vinyl alcohol) (PVA) matrix, the CDs@PVA films effectively filter UV-to-blue light, reducing the blue-light ratio from 27.2% to 2.7%. At the same time, the cyan emission preserves the white light's spectral composition, achieving a color rendering index of 83 ± 5. This dual functionality demonstrates the potential of CDs to enable safer WLEDs that improve both ocular health and lighting quality.

The effect of blue light on cognitive function at workplaces: A systematic review

AIM

Due to the widespread use of artificial lighting in modern workplaces, exposure to blue light is becoming increasingly common. Blue light, known for its shorter wavelength and higher energy, has been linked to both positive and negative effects on cognitive functions and well-being.

OBJECTIVE

This systematic review explores the impact of blue light exposure on cognitive performance and sleep in various workplace settings.

MATERIAL AND METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Using predefined inclusion and exclusion criteria, the team searched three reputable databases (PubMed, Web of Science, and Scopus). Two authors independently screened the search results and the three other authors performed the data extraction and validation from the selected documents. The quality of the articles was assessed using the quality assessment checklist provided by The Joanna Briggs Institute (JBI).

RESULTS

From an initial set of 63 articles, 29 documents met the inclusion criteria. The findings reveal that blue light, particularly at high color temperatures and intensities, enhances cognitive functions such as attention, alertness, and reaction time. However, its effects on memory and sleep were more variable. Exposure to blue-enriched light was consistently associated with improved workplace performance, although some studies reported a mixed or insignificant impact.

CONCLUSION

This review underscores the potential benefits of blue light in workplace settings, particularly for enhancing attention and reaction times. However, variations in study outcomes suggest the need for standardized lighting interventions and further research on its long-term cognitive impacts.

Photoprotective Effects of Phytochemicals on Blue Light-Induced Retinal Damage: Current Evidence and Future Perspectives

The widespread use of light-emitting diodes (LEDs) has increased blue light (BL) exposure, raising concerns about its potential adverse effects on ocular health. Prolonged exposure to BL has been implicated in the pathogenesis of various retinal disorders, including age-related macular degeneration (AMD), primarily through mechanisms involving oxidative stress and inflammation mediated by the overproduction of reactive oxygen species (ROS). This review synthesizes current evidence on the photoprotective properties of dietary bioactive compounds, (e.g., anthocyanins, curcumin, quercetin, myricetin, and resveratrol), with a focus on their potential to mitigate BL-induced retinal damage. Accumulating research suggests that dietary antioxidants, particularly polyphenols, may offer photoprotective benefits. These phytochemicals act by neutralizing ROS and enhancing the retina's endogenous antioxidant capacity. Based on these findings, this review advocates for a food-first approach in future investigations, emphasizing the development of evidence-based dietary recommendations to bolster retinal health and mitigate the risk of BL-related ocular diseases. Considering the current lack of empirical clinical studies examining the impact of BL on human ocular health, future research in the field of BL hazard should prioritize two key approaches: conducting large-scale epidemiological dietary surveys and implementing clinical trials on functional ingredients that have demonstrated beneficial effects against photodamage in preclinical animal studies.

Blue light-induced phototoxicity in retinal cells: implications in age-related macular degeneration

Sunlight exposure is recognized as a risk factor for the development of age-related macular degeneration (AMD), a common neurodegenerative retinal disease in the elderly. Specifically, the blue light wavelengths within sunlight can negatively impact the physiology of light-sensitive retinal cells, including retinal pigmented epithelium (RPE) and photoreceptors. This review explores blue light-induced retinal degeneration, emphasizing the structural and functional impairments in RPE. The initial section provides a brief overview of blue light's effects on photoreceptors, followed by a comprehensive analysis of its detrimental impact on RPE. In vitro studies reveal that blue light exposure induces morphological alterations and functional impairments in RPE, including reduced phagocytic activity, disrupted secretion of neurotrophic factors, and compromised barrier function. Mechanisms of retinal damage, including oxidative stress, inflammation, lipofuscin accumulation, mitochondrial dysfunction and ER stress in RPE, are also explored. The strengths and limitations of in vitro, animal and ex vivo models for studying blue light exposure are discussed, with recommendations for improving reproducibility in future studies.

Circadian de(regulation) in physiology: implications for disease and treatment

Time plays a crucial role in the regulation of physiological processes. Without a temporal control system, animals would be unprepared for cyclic environmental changes, negatively impacting their survival. Experimental studies have demonstrated the essential role of the circadian system in the temporal coordination of physiological processes. Translating these findings to humans has been challenging. Increasing evidence suggests that modern lifestyle factors such as diet, sedentarism, light exposure, and social jet lag can stress the human circadian system, contributing to misalignment; i.e., loss of phase coherence across tissues. An increasing body of evidence supports the negative impact of circadian disruption on several human health parameters. This review aims to provide a comprehensive overview of how circadian disruption influences various physiological processes, its long-term health consequences, and its association with various diseases. To illustrate the relevant consequences of circadian disruption, we focused on describing the many physiological consequences faced by shift workers, a population known to experience high levels of circadian disruption. We also discuss the emerging field of circadian medicine, its founding principles, and its potential impact on human health.

Polydopamine Nanoparticles as Mimicking RPE Melanin for the Protection of Retinal Cells Against Blue Light-Induced Phototoxicity

Exposure of the eyes to blue light can induce the overproduction of reactive oxygen species (ROS) in the retina and retinal pigment epithelium (RPE) cells, potentially leading to pathological damage of age-related macular degeneration (AMD). While the melanin in RPE cells absorbs blue light and prevents ROS accumulation, the loss and dysfunction of RPE melanin due to age-related changes may contribute to photooxidation toxicity. Herein, a novel approach utilizing a polydopamine-replenishing strategy via a single-dose intravitreal (IVT) injection is presented to protect retinal cells against blue light-induced phototoxicity. To investigate the effects of overexposure to blue light on retinal cells, a blue light exposure Nrf2-deficient mouse model is created, which is susceptible to light-induced retinal lesions. After blue light irradiation, retina degeneration and an overproduction of ROS are observed. The polydopamine-replenishing strategy demonstrated effectiveness in maintaining retinal structural integrity and preventing retina degeneration by reducing ROS production in retinal cells and limiting the phototoxicity of blue light exposure. These findings highlight the potential of polydopamine as a simple and effective replenishment for providing photoprotection against high-energy blue light exposure.

The effect of Fernblock® in preventing blue-light-induced oxidative stress and cellular damage in retinal pigment epithelial cells is associated with NRF2 induction

Blue light exposure of the ocular apparatus is currently rising. This has motivated a growing concern about potential deleterious effects on different eye structures. To address this, ARPE-19 cells were used as a model of the retinal pigment epithelium and subjected to cumulative expositions of blue light. The most relevant cellular events previously associated with blue-light-induced damage were assessed, including alterations in cell morphology, viability, cell proliferation, oxidative stress, inflammation, and the induction of DNA repair cellular mechanisms. Consistent with previous reports, our results provide evidence of cellular alterations resulting from repeated exposure to blue light irradiation. In this context, we explored the potential protective properties of the vegetal extract from Polypodium leucotomos, Fernblock® (FB), using the widely known treatment with lutein as a reference for comparison. The only changes observed as a result of the sole treatment with either FB or lutein were a slight but significant increase in γH2AX+ cells and the raise in the nuclear levels of NRF2. Overall, our findings indicate that the treatment with FB (similarly to lutein) prior to blue light irradiation can alleviate blue-light-induced deleterious effects in RPE cells, specifically preventing the drop in both cell viability and percentage of EdU+ cells, as well as the increase in ROS generation, percentage of γH2AX+ nuclei (more efficiently with FB), and TNF-α secretion (the latter restored only by FB to similar levels to those of the control). On the contrary, the induction in the P21 expression upon blue light irradiation was not prevented neither by FB nor by lutein. Notably, the nuclear translocation of NRF2 induced by blue light was similar to that observed in cells pre-treated with FB, while lutein pre-treatment resulted in nuclear NRF2 levels similar to control cells, suggesting key differences in the mechanism of cellular protection exerted by these compounds. These results may represent the foundation ground for the use of FB as a new ingredient in the development of alternative prophylactic strategies for blue-light-associated diseases, a currently rising medical interest.

Recent advances in oxidative degradation of plastics

Oxidative degradation is a powerful method to degrade plastics into oligomers and small oxidized products. While thermal energy has been conventionally employed as an external stimulus, recent advances in photochemistry have enabled photocatalytic oxidative degradation of polymers under mild conditions. This tutorial review presents an overview of oxidative degradation, from its earliest examples to emerging strategies. This review briefly discusses the motivation and the development of thermal oxidative degradation of polymers with a focus on underlying mechanisms. Then, we will examine modern studies primarily relevant to catalytic thermal oxidative degradation and photocatalytic oxidative degradation. Lastly, we highlight some unique studies using unconventional approaches for oxidative polymer degradation, such as electrochemistry.

Adaptive habitat biogeography-based optimizer for optimizing deep CNN hyperparameters in image classification

Deep Convolutional Neural Networks (DCNNs) have shown remarkable success in image classification tasks, but optimizing their hyperparameters can be challenging due to their complex structure. This paper develops the Adaptive Habitat Biogeography-Based Optimizer (AHBBO) for tuning the hyperparameters of DCNNs in image classification tasks. In complicated optimization problems, the BBO suffers from premature convergence and insufficient exploration. In this regard, an adaptable habitat is presented as a solution to these problems; it would permit variable habitat sizes and regulated mutation. Better optimization performance and a greater chance of finding high-quality solutions across a wide range of problem domains are the results of this modification's increased exploration and population diversity. AHBBO is tested on 53 benchmark optimization functions and demonstrates its effectiveness in improving initial stochastic solutions and converging faster to the optimum. Furthermore, DCNN-AHBBO is compared to 23 well-known image classifiers on nine challenging image classification problems and shows superior performance in reducing the error rate by up to 5.14%. Our proposed algorithm outperforms 13 benchmark classifiers in 87 out of 95 evaluations, providing a high-performance and reliable solution for optimizing DNNs in image classification tasks. This research contributes to the field of deep learning by proposing a new optimization algorithm that can improve the efficiency of deep neural networks in image classification.

Trimethylated chitosan-coated flexible liposomes with resveratrol for topical drug delivery to reduce blue-light-induced retinal damage

LED-related blue-light-induced damage can cause eye diseases. However, drug delivery in patients with ocular diseases is faced with various challenges. In this study, we developed flexible liposomes based on trimethylated chitosan (TMC-Lipo) to deliver resveratrol for the treatment of retinal diseases. Flexible liposomes can easily cross various biological barriers. Chitosan and its derivatives have adhesive properties and are widely used in mucoadhesive drug delivery systems. Therefore, we wrapped flexible liposomes with trimethylated chitosan via electrostatic adsorption. The charge of the flexible liposomes became positive after encapsulation in TMC, and they remained stable in artificial tears. We assessed the safety of TMC-Lipo in cellular and zebrafish experiments and found that it can be safely used. In addition, treatment with TMC-Lipo significantly reduced H2O2-induced damage to ARPE-19 cells, restored mitochondrial membrane potential, and protected the cells. TMC-Lipo more easily reached the posterior ocular segment of the mice than liposome nanoparticles and attenuated blue-light-induced retinal cytopathy. Our study demonstrates that effective eye drop formulations can be developed based on trimethylated chitosan, which provides a promising approach for the treatment of ocular diseases.

Effect of Smartphone Use on Sleep in Undergraduate Medical Students: A Cross-Sectional Study

Smartphone use, particularly at night, has been shown to provoke various circadian sleep-wake rhythm disorders such as insomnia and excessive daytime tiredness. This relationship has been mainly scrutinized among patient groups with higher rates of smartphone usage, particularly adolescents and children. However, it remains obscure how smartphone usage impacts sleep parameters in adults, especially undergraduate college students. This study sought to (1) investigate the association between smartphone use (actual screen time) and four sleep parameters: Pittsburgh sleep quality score (PSQI), self-reported screen time, bedtime, and rise time; (2) compare the seven PSQI components between good and poor sleep quality subjects. In total, 264 undergraduate medical students (aged 17 to 25 years) were recruited from the Government Doon Medical College, Dehradun, India. All participants completed a sleep questionnaire, which was electronically shared via a WhatsApp invitation link. Hierarchical and multinomial regression analyses were performed in relation to (1) and (2). The average PSQI score was 5.03 ± 0.86, with approximately one in two respondents (48.3%) having a poor sleep index. Smartphone use significantly predicted respondents' PSQI score (β = 0.142, p = 0.040, R2 = 0.027), perceived screen time (β = 0.113, p = 0.043, R2 = 343), bedtime (β = 0.106, p = 0.042, R2 = 045), and rise time (β = 0.174, p = 0.015, R2 = 0.028). When comparing poor-quality sleep (PSQI ≥ 5) to good-quality sleep (PSQI < 5), with good-quality sleep as the reference, except sleep efficiency and sleep medications (p > 0.05), five PSQI components declined significantly: subjective sleep quality (β = -0.096, p < 0.001); sleep latency (β = -0.034, p < 0.001); sleep duration (β = -0.038, p < 0.001); sleep disturbances (β = 1.234, p < 0.001); and sleep dysfunction (β = -0.077, p < 0.001). Consequently, public health policymakers should take this evidence into account when developing guidelines around smartphone use-i.e., the when, where, and how much smartphone use-to promote improved sleep behaviour and reduce the rate of sleep-wake rhythm disorders.

Biomarker Signature in Aqueous Humor Mirrors Lens Epithelial Cell Activation: New Biomolecular Aspects from Cataractogenic Myopia

Inflammatory, vasculogenic, and profibrogenic factors have been previously reported in vitreous (VH) and aqueous (AH) humors in myopic patients who underwent cataract surgery. In light of this, we selected some mediators for AH and anterior-capsule-bearing lens epithelial cell (AC/LEC) analysis, and AH expression was correlated with LEC activation (epithelial-mesenchymal transition and EMT differentiation) and axial length (AL) elongation. In this study, AH (97; 41M/56F) and AC/LEC samples (78; 35M/43F) were collected from 102 patients who underwent surgery, and biosamples were grouped according to AL elongation. Biomolecular analyses were carried out for AH and LECs, while microscopical analyses were restricted to whole flattened AC/LECs. The results showed increased levels of interleukin (IL)-6, IL-8, and angiopoietin-2 (ANG)-2 and decreased levels of vascular endothelium growth factor (VEGF)-A were detected in AH depending on AL elongation. LECs showed EMT differentiation as confirmed by the expression of smooth muscle actin (α-SMA) and transforming growth factor (TGF)-βR1/TGFβ isoforms. A differential expression of IL-6R/IL-6, IL-8R/IL-8, and VEGF-R1/VEGF was observed in the LECs, and this expression correlated with AL elongation. The higher VEGF-A and lower VEGF-D transcript expressions were detected in highly myopic LECs, while no significant changes were monitored for VEGF-R transcripts. In conclusion, these findings provide a strong link between the AH protein signature and the EMT phenotype. Furthermore, the low VEGF-A/ANG-2 and the high VEGF-A/VEGF-D ratios in myopic AH might suggest a specific inflammatory and profibrogenic pattern in high myopia. The highly myopic AH profile might be a potential candidate for rating anterior chamber inflammation and predicting retinal distress at the time of cataract surgery.

The inhibitory and inactivating effects of visible light on SARS-CoV-2: A narrative update

Prior to the coronavirus disease-19 (COVID-19) pandemic, the germicidal effects of visible light (λ = 400 - 700 nm) were well known. This review provides an overview of new findings that suggest there are direct inactivating effects of visible light - particularly blue wavelengths (λ = 400 - 500 nm) - on exposed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virions, and inhibitory effects on viral replication in infected cells. These findings complement emerging evidence that there may be clinical benefits of orally administered blue light for limiting the severity of COVID-19. Possible mechanisms of action of blue light (e.g., regulation of reactive oxygen species) and important mediators (e.g., melatonin) are discussed.

Permissible viewing times of educational projector and TV

Projectors have become one major medium in modern teaching, with large area-size displays emerging as an alternative. What concerns the general public is whether such eLearning would impose threat on eyes, by noting blue enriched white light to be hazardous to retina and else. Especially, little was known about their permissible viewing time under a certain viewing clarity. We had hence carried out a quantitative study with the use of a blue-hazard quantification spectrometer to determine the permissible viewing time when using a projector and a large size TV screen for displaying. Surprisingly, the large TV screen could permit a much longer viewing time, meaning which is more eye-friendly. It is plausibly because its resolution is much higher than that of the projector. Two dilemmas were observed in such eLearning; those sitting in the front would suffer a much higher illuminance, leading to a much shorter viewing time, while those sitting in the back would need a far much larger font size to see clearly. To ensure both viewing clarity and a sufficiently long permissible viewing time, orange text on black background is suggested to replace the defaulted black text on white background. The permissible viewing time could hence drastically increase from 1.3 to 83 h at 2 m by viewing a 30 pt font for the TV and from 0.4 to 54 h for the projection. At 6 m, the permissible viewing time was increased from 12 to 236 h for the TV and from 3 to 160 h for the projection, based on a viewable 94 pt font. These results may help educators and other e-display users to wisely apply the display tools with safety.

Blue light exposure collapses the inner blood-retinal barrier by accelerating endothelial CLDN5 degradation through the disturbance of GNAZ and the activation of ADAM17

Blue light is part of the natural light spectrum that emits high energy. Currently, people are frequently exposed to blue light from 3C devices, resulting in a growing incidence of retinopathy. The retinal vasculature is complex, and retinal vessels not only serve the metabolic needs of the retinal sublayers, but also maintain electrolyte homeostasis by forming the inner blood-retinal barrier (iBRB). The iBRB, which is primarily composed of endothelial cells, has well-developed tight junctions. However, with exposure to blue light, the risks of targeting retinal endothelial cells are currently unknown. We found that endothelial claudin-5 (CLDN5) was rapidly degraded under blue light, coinciding with the activation of a disintegrin and metalloprotease 17 (ADAM17), even at non-cytotoxic lighting. An apparently broken tight junction and a permeable paracellular cleft were observed. Mice exposed to blue light displayed iBRB leakage, conferring attenuation of the electroretinogram b-wave and oscillatory potentials. Both pharmacological and genetic inhibition of ADAM17 remarkably alleviated CLDN5 degradation induced by blue light. Under untreated condition, ADAM17 is sequestered by GNAZ (a circadian-responsive, retina-enriched inhibitory G protein), whereas ADAM17 escapes from GNAZ by blue light illuminance. GNAZ knockdown led to ADAM17 hyperactivation, CLDN5 downregulation, and paracellular permeability in vitro, and retinal damage mimicked blue light exposure in vivo. These data demonstrate that blue light exposure might impair the iBRB by accelerating CLDN5 degradation through the disturbance of the GNAZ-ADAM17 axis.

Proper use of light environments for mitigating the effects of COVID-19 and other prospective public health emergency lockdowns on sleep quality and fatigue in adolescents

Coronavirus disease 2019 (COVID-19) remains a public health emergency of international concern, and some countries still implement strict regional lockdowns. Further, the upcoming 2023 Asian Games and World University Games will implement a closed-loop management system. Quarantine can harm mental and physical health, to which adolescents are more vulnerable compared with adults. Previous studies indicated that light can affect our psychology and physiology, and adolescents were exposed to the artificial light environment in the evening during the lockdown. Thus, this study aimed to establish and assess appropriate residential light environments to mitigate the effects of lockdowns on sleep quality and fatigue in adolescents. The participants were 66 adolescents (12.15 ± 2.45 years of age) in a closed-loop management environment, who participated in a 28-day (7-day baseline, 21-day light intervention) randomized controlled trial of a light-emitting diode (LED) light intervention. The adolescents were exposed to different correlated color temperature (CCT) LED light environments (2000 K or 8000 K) for 1 h each evening. The results for self-reported daily sleep quality indicated that the low CCT LED light environment significantly improved sleep quality (p < 0.05), and the blood test results for serum urea and hemoglobin indicated that this environment also significantly reduced fatigue (p < 0.05) and moderately increased performance, compared to the high CCT LED light environment. These findings can serve as a springboard for further research that aims to develop interventions to reduce the effects of public health emergency lockdowns on mental and physical health in adolescents, and provide a reference for participants in the upcoming Asian Games and World University Games.

Light as a Modulator of Non-Image-Forming Brain Functions—Positive and Negative Impacts of Increasing Light Availability

Light use is rising steeply, mainly because of the advent of light-emitting diode (LED) devices. LEDs are frequently blue-enriched light sources and may have different impacts on the non-image forming (NIF) system, which is maximally sensitive to blue-wavelength light. Most importantly, the timing of LED device use is widespread, leading to novel light exposure patterns on the NIF system. The goal of this narrative review is to discuss the multiple aspects that we think should be accounted for when attempting to predict how this situation will affect the NIF impact of light on brain functions. We first cover both the image-forming and NIF pathways of the brain. We then detail our current understanding of the impact of light on human cognition, sleep, alertness, and mood. Finally, we discuss questions concerning the adoption of LED lighting and screens, which offer new opportunities to improve well-being, but also raise concerns about increasing light exposure, which may be detrimental to health, particularly in the evening.

Wearable Spectroradiometer for Dosimetry

Available wearable dosimeters suffer from spectral mismatch during the measurement of broadband UV and visible radiation in environments that receive radiation from multiple sources emitting differing spectra. We observed this type of multi-spectra environment in all five Washington State cannabis farms visited during a field study investigating worker exposure to ultraviolet radiation in 2018. Spectroradiometers do not suffer from spectral mismatch in these environments, however, an extensive literature review conducted at the time of writing did not identify any spectroradiometers that were directly deployable as wearable dosimetry devices. To close this research gap, we developed a microcontroller system and platform that allows for researchers to mount and deploy the Ocean Insight Flame-S Spectroradiometer as a wearable device for measurement of UV and visible wavelengths (300 to 700 nm). The platform validation consisted of comparing measurements taken under platform control with measurements taken with the spectrometer controlled by a personal computer running the software provided by the spectroradiometer manufacturer. Three Mann-Whitney U-Tests (two-tailed, 95% CI), one for each intensity condition, compared the central tendency between the total spectral power (TSP), the integral of a spectrum measurement, measured under both control schemas. An additional analysis of per pixel agreement and overall platform stability was performed. The three Mann-Whitney tests returned no significant difference between the set of TSPs for each filter condition. These results suggest that the spectroradiometer takes measurements of equivalent accuracy under both control schemas, and can be deployed as a wearable device for the measurement of wavelength resolved UV and visible radiation.