Control Lenses Research Articles

Cognitive and motivational qualities of task instruction: Cognitive appraisals and achievement emotions of Swedish primary teacher students

Given the crucial role of primary teachers in shaping pupils' development, equipping primary teacher students with the necessary skills, including information-seeking skills, is fundamentally important. The aim of this study is to gain a better understanding of the process of achieving such skills by exploring the interplay between cognitive appraisals and achievement emotions and the way in which these are affected by the quality of instructions experienced. Instruction librarians' support in relation to instructions and how these can be designed to promote achievement are also investigated.Six Swedish primary teacher students were studied through in-depth semi-structured interviews over a period of 10 weeks. The methodological tool Geneva affect label coder was used for the mapping and categorization of appraisals and emotions. The analysis of the qualitative data was theory driven and deductively interpreted through the lens of Pekrun's control–value theory of achievement emotions, Scherer's semantic space of emotions, and Kuhlthau's information search process model.The cognitive appraisals identified were uncertainty, certainty, and negative and positive intrinsic motivation. The achievement emotions found in relation to cognitive quality were anger/frustration, anxiety, and hopelessness, and those linked to motivational quality were enjoyment and boredom. Uncertainty and negative intrinsic motivation/failure elicited emotions related to cognitive quality, and negative/positive intrinsic motivation and certainty determined emotions related to motivational quality. The interplay between appraisals and emotions was complex, involving feedback loops and reciprocal causation. The support from instruction librarians experienced was related to the students' ability to master the instructions and their cognitive qualities.The study has theoretical and methodological implications for information behavior and information literacy research in its application of appraisal theories and methodological tools. It also has practical implications for academic instruction librarians supporting students in the process of achieving information-seeking skills. By understanding how students experience support and the relations to the quality of task instructions, support can be designed in ways that promote positive achievement emotions and by implication achievement.

Evaluating the Effect of a Myopia Control Spectacle Lens Among Children in Israel: 12-Month Results

To investigate the effectiveness of a novel spectacle lens designed to slow the progression of myopia in children. A prospective, randomized, double blind clinical trial. One hundred twenty-six Israeli children aged 6-13 years with spherical equivalent (SER) refractive errors of -0.5 to -6.25 diopters (D) were randomized into either the Shamir Myopia Control (SMC) lens design group or the conventional single-vision spectacle lenses (SVL), the control group. Outcomes measured were changes in axial length and cycloplegic refraction as well as subjective rating of visual experience over a period of 12 months. At 12 months, AL and SER progression were slowed by 0.11 mm (35%, P < .05) and 0.16 D (25%, P=.122), respectively. In the subgroup of 6-10-year-olds, AL and SER progression were slowed by 0.17 mm (41%, P < .05) and 0.31 D (43%, P < .05), respectively. Similarly, for the subgroup of children with 2 myopic parents AL and SER progression were slowed by 0.15 mm (45% P < .05) and 0.36 D (42%, P < .05), respectively. Subjective visual experience reported in the 12-month questionnaire revealed no difference between the SMC and SVL groups, and average daily wearing hours were also not different between the groups: 14 (±1.4) and 13.8 (±2.3) hours, respectively. The study continues to its second year. SMC lenses were effective in slowing the progression of SER and AL, especially for younger children and those having 2 myopic parents. The subjective rating of visual experience and the daily duration of use reported by the SMC group at 12 months were similar to the control group, indicating good lens tolerability.

Invited Session II: Myopia and myopia control: Ocular growth regulation and the complexities of optical defocus decoding: A perspective from studies in chicks.

The COVD pandemic has seen a further rise in the prevalence of myopia world-wide, adding to the urgency of effective treatments that can prevent or slow myopia progression. In addition to multifocal soft contact lenses and orthokeratology lenses for myopia control, a variety of novel spectacle lenses involving modified peripheries are either currently under clinical trial or recently approved. Yet still unresolved questions related to underlying retinal mechanisms of action represent handicaps to their further refinement and improved efficacy. In this presentation, results will be presented from studies using young chicks as a model for manipulating the amount, retinal location and timing of imposed optical defocus, as well as the spatial frequency content of retinal images (with Bangerter foils), by way of offering some additional insights into mechanisms. The predictive values of choroidal thickness changes, as well as eye shape changes, as determinants of "myopia control", will also be considered.

Unbalanced redox status network as an early pathological event in congenital cataracts

The lens proteome undergoes dramatic composition changes during development and maturation. A defective developmental process leads to congenital cataracts that account for about 30% of cases of childhood blindness. Gene mutations are associated with approximately 50% of early-onset forms of lens opacity, with the remainder being of unknown etiology. To gain a better understanding of cataractogenesis, we utilized a transgenic mouse model expressing a mutant ubiquitin protein in the lens (K6W-Ub) that recapitulates most of the early pathological changes seen in human congenital cataracts. We performed mass spectrometry-based tandem-mass-tag quantitative proteomics in E15, P1, and P30 control or K6W-Ub lenses. Our analysis identified targets that are required for early normal differentiation steps and altered in cataractous lenses, particularly metabolic pathways involving glutathione and amino acids. Computational molecular phenotyping revealed that glutathione and taurine were spatially altered in the K6W-Ub cataractous lens. High-performance liquid chromatography revealed that both taurine and the ratio of reduced glutathione to oxidized glutathione, two indicators of redox status, were differentially compromised in lens biology. In sum, our research documents that dynamic proteome changes in a mouse model of congenital cataracts impact redox biology in lens. Our findings shed light on the molecular mechanisms associated with congenital cataracts and point out that unbalanced redox status due to reduced levels of taurine and glutathione, metabolites already linked to age-related cataract, could be a major underlying mechanism behind lens opacities that appear early in life.

Retrospective Analysis of Axial Length Changes in Overnight Orthokeratology in an Academic Myopia Control Clinic.

Although the myopia control efficacy of orthokeratology lenses has been established with clinical trials, reports of axial length change in non-study-based patient care are scarce. This study investigates the use of orthokeratology lenses for myopia control in a clinical population and compares axial elongation against those published in recent clinical investigations. This study aimed to investigate factors affecting axial elongation during use of orthokeratology lenses for myopia control in an academic clinical setting. This study was a retrospective consecutive case series from the Myopia Control Clinic at the Herbert Wertheim School of Optometry at the University of California, Berkeley (Berkeley, CA). Patients ranging from 5 to 18 years old using orthokeratology for at least 1 year were included in the study. Data from 102 patients' eyes were analyzed at baseline (before the initiation of treatment) and after 1 year of wear (12 ± 3 months). Multivariate analysis was undertaken to identify factors significantly associated with axial elongation over this period. Mean (±standard deviation) spherical equivalent refraction and axial length at baseline were -2.54 (±1.21) D and 24.53 (±0.82) mm, respectively. By the 1-year follow-up, eyes had shown significant axial elongation (0.18 ± 0.24 mm; P < .001), which was found to be inversely correlated with age ( P < .001). Race, sex, baseline axial length, and baseline refraction were not significantly associated with axial elongation. Factors influencing axial length and the magnitude of axial elongation in our orthokeratology patient population are consistent with orthokeratology treatment groups from published randomized clinical trials and support the use of these lenses for myopia control in a clinical practice setting.

Quality of life after wearing multifocal contact lenses for myopia control for 2 weeks in the BLINK Study.

To validate Pediatric Refractive Error Profile 2 (PREP2) subscales that can be used to evaluate contact lens wearers and compare vision-specific quality of life measurements between children wearing multifocal and single vision contact lenses for 2 weeks. Two hundred and ninety-four myopic children aged 7-11 years (inclusive) were enrolled in the 3-year, double-masked Bifocal Lenses In Nearsighted Kids (BLINK) Study. Participants completed the PREP2 survey after having worn contact lenses for 2 weeks. The Vision, Symptoms, Activities and Overall PREP2 subscales were used to compare participants' subjective assessment while wearing +1.50 or +2.50 D add multifocal or single vision contact lenses. Rasch analysis was used to validate each subscale and to compare participants' subjective assessment of contact lens wear. Item fit to the Rasch model was good for all scales, with no individual items having infit mean square statistics outside the recommended range (0.7-1.3). Response category function was acceptable for all subscales, with ordered category thresholds. Measurement precision, assessed by the Rasch person reliability statistic, was less than ideal (≥0.8) for three of the subscales, but met the minimum acceptable standard of 0.5. Scores for the Vision subscale differed by treatment assignment (p = 0.03), indicating that participants with the highest add power reported statistically worse quality of vision, although the difference was only 3.9 units on a scale of 1-100. Girls reported fewer symptoms than boys (p = 0.006), but there were no other differences between boys and girls. Rasch analysis demonstrates that the PREP2 survey is a valid instrument for assessing refractive error-specific quality of life. These results suggest that vision-related quality of life is not meaningfully affected by 2 weeks of soft multifocal contact lens wear for myopia control.

Attitudes and knowledge of myopia management by Spanish optometrists

PurposeTo investigate the knowledge, training and clinical practice of Spanish optometrists about preventing and controlling myopia progression.MethodsA web-based questionnaire was distributed to Spanish optometrists through social networks, optometric professional bodies and one of the major Spanish optometrists' associations to assess practitioner perception, understanding, and self-reported clinical practice behavior related to myopia diagnosis and management.ResultsA total of 534 optometrists with a mean age of 40.8 ± 10.3 years completed the survey. Most respondents have been practicing optometry for more than 20 years (89.8%), report having actively treated childhood myopia (82.4%), and are very concerned about the increasing frequency of pediatric myopia in their daily practice (85.3%). Almost all of the respondents (97.3%) agreed that the efficacy of treatment is related to the age at which it is prescribed, and more than half (53.6%) considered a progression higher than − 0.50 and up to − 1.00D as the minimum necessary to consider a myopia management option. Respondents who reported actively managing childhood myopia considered orthokeratology, atropine and soft-defocus contact lenses the most effective myopia control interventions. However, the most frequently prescribed form of myopia correction by Spanish optometrists was single-vision spectacles, followed by orthokeratology and soft-defocus contact lenses.ConclusionsSpanish optometrists are very active in the management of myopia, especially by fitting orthokeratology lenses or dual-focus soft contact lenses for myopia control, but there is still potential for improvement in the methodology they follow for both the diagnosis and management of myopia.

High myopia control is comparable between multifocal rigid gas-permeable lenses and spectacles.

Ocular pathology may be reduced by slowing myopia progression. The purpose of this study was to evaluate the potential of a novel custom-designed rigid gas permeable (RGP) contact lens to control high myopia by comparing the efficacy of multifocal RGP lenses and single-vision spectacles for high myopia control. The medical records of children fitted with spectacles or multifocal rigid gas-permeable lenses between January 2018 and May 2020 were retrospectively reviewed. Children (5-17 years) with non-cycloplegic spherical equivalent refraction of ≤ -6.00 D or spherical equivalent refraction > - 6.00 D with baseline axial length ≥ 26.5 mm, and astigmatism of ≥ -2.00 D were included. Axial length and refraction were measured at baseline, before fitting the participants with multifocal rigid gas-permeable lenses or spectacles, and at 1- and 2-year follow-up visits. Changes in axial length were compared between the groups. Among the 77 children with 1-year follow-up data, the mean axial elongation was 0.20 ± 0.17 mm and 0.21 ± 0.14 mm in the multifocal rigid gas-permeable and control groups, respectively, without significant differences between groups (F = 0.004, p = 0.835). Among the 41 patients who completed 2 years of follow-up, the mean axial elongation values in the multifocal rigid gas-permeable and control groups were 0.21 ± 0.15 mm and 0.24 ± 0.13 mm, respectively, at the 1-year follow-up, and 0.37 ± 0.27 mm and 0.43 ± 0.23 mm, respectively, at the 2-year follow-up, without significant between-group differences at either time point (p = 0.224). Axial length increased at a similar rate in both the control (spectacles) and multifocal rigid gas-permeable lens groups, suggesting that multifocal rigid gas-permeable lenses have no significant impact on controlling high myopia progression compared with spectacles.

Conservators, Creativity, and Control

ABSTRACT This article explores the role of conservators and focusses on their creative agency in the preservation of cultural heritage. It argues that conservators constitute a ‘recursive public’ who collectively make the field both highly collaborative and highly modifiable. The author then sets out how conservators engage in a form of ‘ontological constructivism’ where they use their creative agencies in adversarial, anexact, and generative processes and act as ‘art-developers’ to commit to the next version of a work. Drawing parallels with software development, the author proposes that conservation should be seen as a form of version control that creates time-stamped ‘versions of record’ that persist until the next cycle of care. To emphasise the lack of finality in any artwork the author produces a series of ‘endgames’ to illustrate the ontologically open-ended nature of cultural heritage. The article suggests that in exploring the distributed nature of creative agency through the lens of version control, conservation can provide greater understanding into the real conditions of art and cultural production and how they continue to evolve over time. This then helps disrupt conventional notions of authorship and allows conservation to contribute to a more inclusive understanding of art and culture in our institutions.

Multiple segment spectacle lenses for myopia control. Part 2: Impact on myopia progression.

Initial studies have suggested that multiple segment (MS) spectacle lenses can reduce the progression rate of childhood myopia and axial eye growth. This paper aimed to compare the effectiveness of two different available designs of MS lens and to explore the nature of their control effect. Published data from the only two clinical trials in which changes in mean spherical equivalent refraction (SER) and axial length (AL) for matched groups of myopic children wearing either MS or single-vision (SV) spectacle corrections, recorded over a period of at least 2 years, were further analysed and compared. Both trials involved Chinese children of similar ages and visual characteristics, but the trials were located in different cities. The two MS lenses examined were MiyoSmart or DIMS (Hoya) and Stellest (Essilor). Absolute changes in SER and AL differed over time during the two trials. However, if the results were expressed in terms of efficacy over successive 6-month periods, then the two MS lenses produced broadly similar results (initial efficacy for the control of myopia progression of about 60%-80%, declining over 2 years to about 35%-55%). Control appears to be absolute rather than proportional. Myopia control may be due to either the additional myopic defocus induced by the MS lenses (i.e., asymmetry of the through-focus image changes about the distance focus) or to the general reduction in image contrast that the lenslets create in the peripheral field. Multiple segment spectacle lenses offer a valuable new approach to the control of myopia progression in children. Further work is required to clarify their mechanism of action and to optimise their design parameters.

Tear film dynamics of a new soft contact lens.

To present the objective metrics from a study that evaluated the clinical performance of a senofilcon A contact lens, both with and without a new manufacturing technique. This was a single-site, five-visit, controlled, randomised, subject-masked, 2 × 2 crossover study (May-August 2021) with a 2-week lens dispensing period (bilateral wear) and weekly follow-up visits. Healthy adult (18-39 years), habitual spherical silicone hydrogel contact lens wearers were included. The High-definition (HD) Analyzer™ was used to objectively measure the lens-on-eye optical system resulting from the study lenses at 1-week follow-up. Measurements assessed were vision break-up time (VBUT), modulation transfer function (MTF) cutoff, Strehl ratio (SR), potential visual acuity (PVA) for 100% contrast and objective scatter index (OSI). Of the 50 enrolled participants, 47 (94.0%) were randomly assigned to one of the two possible lens wear sequences (test/control or control/test) and dispensed at least one study lens. The estimated odds ratio of VBUT > 10 s was 1.582 (95% confidence interval [CI]: 1.009 to 2.482) in test versus control lens. The least squares mean difference estimates of MTF cutoff, SR and PVA for 100% contrast between test versus control lens were 2.243 (95% CI: 0.012 to 4.475), 0.011 (95% CI: -0.002 to 0.023) and 0.073 (95% CI: -0.001 to 0.147), respectively. The estimated ratio of median OSI between test versus control lens was 0.887 (95% CI: 0.727 to 1.081). The test lens demonstrated superiority over the control lens with respect to VBUT and MTF cutoff. No serious adverse events were reported; eight adverse events (three ocular, five non-ocular) were indicated by six participants during the study. The test lens demonstrated an increased probability of having a longer VBUT (>10 s). Future studies may be designed to assess the efficacy and long-term use of the test lens in a larger population.

Understanding a Class of Decentralized and Federated Optimization Algorithms: A Multirate Feedback Control Perspective

Distributed algorithms have been playing an increasingly important role in many applications such as machine learning, signal processing, and control. Significant research efforts have been devoted to developing and analyzing new algorithms for various applications. In this work, we provide a fresh perspective to understand, analyze, and design distributed optimization algorithms. Through the lens of multirate feedback control, we show that a wide class of distributed algorithms, including popular decentralized/federated schemes, can be viewed as discretizing a certain continuous-time feedback control system, possibly with multiple sampling rates, such as decentralized gradient descent, gradient tracking, and federated averaging. This key observation not only allows us to develop a generic framework to analyze the convergence of the entire algorithm class, but, more importantly, it also leads to an interesting way of designing new distributed algorithms. We develop the theory behind our framework and provide examples to highlight how the framework can be used in practice.

Eye accommodation-inspired neuro-metasurface focusing

The human eye, which relies on a flexible and controllable lens to focus light onto the retina, has inspired many scientific researchers to understand better and imitate the biological vision system. However, real-time environmental adaptability presents an enormous challenge for artificial eye-like focusing systems. Inspired by the mechanism of eye accommodation, we propose a supervised-evolving learning algorithm and design a neuro-metasurface focusing system. Driven by on-site learning, the system exhibits a rapid response to ever-changing incident waves and surrounding environments without any human intervention. Adaptive focusing is achieved in several scenarios with multiple incident wave sources and scattering obstacles. Our work demonstrates the unprecedented potential for real-time, fast, and complex electromagnetic (EM) wave manipulation for various purposes, such as achromatic, beam shaping, 6 G communication, and intelligent imaging.

A thermally controlled high-Q metasurface lens

Dynamic metasurface control is a promising yet challenging prospect for next generation optical components. Here, we design and characterize a thermally controllable metasurface lens, with a high-quality-factor (high-Q) resonance working as both the basis of the lensing behavior and method for efficient modulation. Our high-Q lens is constructed via a zone plate architecture comprised of alternating regions with and without resonant character. Non-resonant regions block transmission, while resonant regions—with measured Qs up to ∼1350—transmit only on resonance. By leveraging the thermo-optic effect, we dynamically control the spectral position of the high-Q resonance to achieve wavelength selectivity of the focusing behavior. Due to the sharp spectral linewidth and amplitude variation of the high-Q resonance, thermal tuning can further result in metasurface switching, where the lensing behavior is changed between on and off states. For a device utilizing only moderate Q-factors of ∼350, the resonance's FWHM can be shifted with temperature changes of only 50 °C, and the device can be fully switched off when operating at 100 °C. Our work provides an initial experimental demonstration of dynamic control of a local high-Q wavefront shaping metasurface.

Dual-focus contact lenses for myopia control modify central retinal electrophysiology in humans.

Dual-focus contact lenses create two focal planes, one providing a clear retinal image while the other imposes myopic defocus on the retina to slow myopia progression. This study used global-flash multifocal electroretinogram (gmfERG) response amplitudes to compare central versus peripheral retinal responses under dual-focus conditions and to assess the optimal degree of myopic defocus compared with a single-vision control lens. Twenty participants each underwent three gmfERG trials, wearing a spectacle correction over dual-focus contact lenses with plano central power and peripheral secondary focal powers of either +2.00D, +4.00D or a plano single-vision lens. We compared amplitudes and latencies of the gmfERG direct and induced components (DC and IC) within participants, between the three different contact lens powers and at different retinal eccentricities (gmfERG ring). We observed significant differences in the gmfERG responses between the single-vision and dual-focus contact lenses. Overall, DC amplitudes peaked between zero and +2.00D secondary power, while IC amplitudes were maximal between +2.00D and +4.00D. Compared with the single-vision control, the greatest increase in DC and IC amplitudes while wearing dual-focus lenses occurred within the central 10° of the retina. There was no interaction effect between gmfERG ring (eccentricity) and secondary power, and no difference in the latency of the gmfERG responses between different powers. We found that dual-focus contact lenses with a +2.00D secondary power are close to that expected to induce the greatest increase in gmfERG responses relative to a single-vision lens. Dual-focus lenses produced the highest DC and IC response amplitudes relative to a single-vision lens in the central 10° of the retina. This suggests that dual-focus contact lenses slow myopia progression by modifying central rather than peripheral retinal activity.

Influence of isofocal intraocular lenses on objective refraction based on autorefraction and aberrometry.

To evaluate and compare the objective refractions obtained by autorefraction and aberrometry under different lighting conditions with an isofocal intraocular lens (Isopure, BVI medical, Liége, Belgium) compared to a monofocal control lens (Micropure, BVI medical, Liége, Belgium) with the same platform and material. Prospective, comparative and randomized study on patients undergoing cataract surgery and bilateral isofocal or monofocal IOL implantation. A total of 44 subjects were randomly assigned to either the isofocal group (n = 22) or the Micropure (n = 22). Manifest refraction (MR) was always performed under the same lighting conditions for all the patients. For objective refraction the autorefractor KR8800 and the aberrometer OPD-Scan III (Nidek Inc., Tokyo, Japan.) were used. For each eye included in the study, six result sets were collected: MR, AR (autorefraction measured with the autorefractor), WF-P and WF-M (Zernike-coefficients-based objective refraction, photopic and mesopic pupil size), OPD-C and OPD-M (autorefraction measured with the aberrometer in photopic and mesopic conditions). The mean sphere for MR was 0.03 ± 0.32D for the Isopure group and 0.24 ± 0.22D for the monofocal group (p = 0.013). For the Isopure group, Friedman analysis showed statistically significant differences for sphere measured with WF-P (p = 0.035), WF-M (p = 0.018) and OPD-M (p = 0.000), and SE measured with OPD-M (p = 0.004). In the Micropure lens group, the Friedman analysis showed differences for all values studied (p < 0.05). Correlation coefficients showed that AR is the objective method with the strongest correlation values for all components of refraction for both groups. The modification of the surfaces of the isofocal lens does not have a negative impact on the refraction obtained by AR compared to a standard monofocal intraocular lens.

ON and OFF receptive field processing in the presence of optical scattering.

The balance of ON/OFF pathway activation in the retina plays a role in emmetropization. A new myopia control lens design uses contrast reduction to down-regulate a hypothesized enhanced ON contrast sensitivity in myopes. The study thus examined ON/OFF receptive field processing in myopes and non-myopes and the impact of contrast reduction. A psychophysical approach was used to measure the combined retinal-cortical output in the form of low-level ON and OFF contrast sensitivity with and without contrast reduction in 22 participants. ON responses were lower than OFF responses (ON 1.25 ± 0.03 vs. OFF 1.39 ± 0.03 log(CS); p < 0.0001) and myopes showed generally reduced sensitivities (myopes 1.25 ± 0.05 vs. non-myopes 1.39 ± 0.05 log(CS); p = 0.05). These findings remained unaffected by contrast reduction (p > 0.05). The study suggests that perceptual differences in ON and OFF signal processing between myopes and non-myopes exist but cannot explain how contrast reduction can inhibit myopia development.

Stories of Leadership: Leading with Empathy through the COVID-19 Pandemic

Leader–follower interactions during times of complexity are critical in managing rapid change demands and ensuring organizational sustainability. Between early 2020 and 2023, many organizations worldwide witnessed an unprecedented need for organizational change that rapidly transformed the work environment. This study focused on understanding the contexts of leader and follower interactions during times of change using the shifting organizational landscapes of the COVID-19 pandemic. Applying a qualitative methodology, we collected data from 12 leaders across multiple business sectors in Africa, Asia, and the United States using semi-structured interviews. We then transcribed the interviews and applied an iterative phronetic approach to analyze the data by engaging complexity leadership, emotion in organizations, leading with empathy, belonging, and power and control as theoretical lenses for data analysis. We analyzed how individual leadership experiences during a time of complexity fostered a shift in leadership paradigms and leadership styles within organizations. The findings indicated that due to the unprecedented situations faced during COVID-19, leaders shifted from leadership styles that applied a lens of power and control to an adaptable model that follows the framework of complexity leadership and applies a lens of leading with emotional intelligence. The findings provided a nuanced understanding of the leader–follower relationship by allowing for a complex and varied description of how individuals discursively situate their experiences around issues of power and control. The findings also showed that leaders became more intentional about leading, purposely changing their leadership style to create an environment that supported open communication, belonging, empathy, and awareness. The findings also suggested that when leaders adapt elements of emotional intelligence in leading during times of organizational complexity, they do so with the goal of motivating others and creating a feeling of connection with followers. Theoretical and practical implications are discussed.

Targeting the intrinsically photosensitive retinal ganglion cell to reduce headache pain and light sensitivity in migraine: A randomized double-blind trial

Approximately 80% of patients with migraine report light sensitivity during attacks and almost half report that following headache, light sensitivity is the most bothersome symptom. Light wavelengths stimulating intrinsically photosensitive retinal ganglion cells (IPRGCs) exacerbate headache-associated light sensitivity; green light is most comfortable. We developed optical tints that block wavelengths exacerbating migraine pain and transmit wavelengths that are most comfortable. We studied patients with migraine to determine if spectacles with these tints ameliorate headache pain and light sensitivity.Randomized participants wore control lenses or lenses blocking light wavelengths that stimulate IPRGCs. Participants applied the lenses at migraine onset and recorded baseline, two- and four-hour headache pain on an 11-point scale. Primary endpoint was pain reduction at two hours following the first severe or very severe headache. Statistical tests used included mixed-effects model analysis, Mann-Whitney test, Cochran-Mantel-Haenszel test, Shapiro-Wilk test, Welch t-test.In 78 subjects, two- and four-hour pain reduction was not significantly different between groups. In post-hoc analyses of headaches with baseline pain scores ≥ 2, a mixed-effects model suggested that IPRGC lenses were associated with clinically and statistically significant reductions in two- and four-hour headache pain. In post-hoc analyses, fewer subjects wearing IPRGC lenses reported two-hour light sensitivity.Preliminary evidence suggests that optical tints engineered to reduce stimulation of IPRGCs may reduce migraine-associated pain and light sensitivity.Trial Registration: This study was registered at ClinicalTrials.gov (NCT04341298).

Universal Approximation Power of Deep Residual Neural Networks Through the Lens of Control

In this paper we show that deep residual neural networks have the power of universal approximation by using, in an essential manner, the observation that these networks can be modeled as nonlinear control systems. We first study the problem of using a deep residual neural network to exactly memorize training data by formulating it as a controllability problem for an ensemble control system. Using techniques from geometric control theory, we identify a class of activation functions that allow us to ensure controllability on an open and dense submanifold of sample points. Using this result, and resorting to the notion of monotonicity, we establish that any continuous function can be approximated on a compact set to arbitrary accuracy, with respect to the uniform norm, by this class of neural networks. Moreover, we provide optimal bounds on the number of required neurons.