Glare Reduction Research Articles

Optimizing Classroom Lighting: Balancing Illuminance Uniformity and Glare Control with Led Technology

Indoor lighting environment significantly impacts students’ concentration and learning performance. Optimal lighting conditions enhance reading speed, accuracy, and comprehension abilities. In contrast, poor lighting conditions may lead to decreased concentration and increased errors in tasks. Therefore, classroom lighting is an important factor to consider in classroom design to optimize cognitive efficiency of students. Current classroom lighting solutions using LED systems have met European Norm (EN) standard in terms of illuminance and energy efficiency. However, although the issue of glare has been addressed, it has not been completely resolved. This study introduces a solution for glare-free classroom lighting that maintains uniformity while adhering to existing standards. This approach aims to create a visually comfortable learning environment, balancing effective lighting with glare reduction.

Glare Reduction of the Artificial Lighting System Using the Digital Software Solution

Artificial lighting systems are an integral part of production halls. These systems are typically used to supplement daylight, although in some cases they are the sole source of lighting in the workplace. Every artificial lighting system is accompanied by an unfavourable phenomenon: glare. This phenomenon is one of the main factors affecting the quantitative parameters of internal lighting systems. Glare needs to be reduced in each production area to ensure visual well-being, which is linked to the visual performance of employees and consequently affects the efficiency and productivity of production. Obtaining information about glare in a real system is a difficult and lengthy process. However, digital software tools can be used in a simulated environment to predict and reduce glare. This article addresses the issue of reducing glare in artificial lighting systems using a digital software solution. The introduction discusses the theoretical aspects of glare caused by artificial lighting systems. This is followed by a practical example using the simulation method with the Dialux Evo tool to reduce glare in the workplace. The conclusion of the article provides an analysis of the results achieved and offers recommendations for practical implementation.

Multi-Criteria Decision-Making for Selecting Solar Window Film Sheets for Energy Saving in Buildings

Recently, there have been several advancements in the field of sustainable energy solutions, particularly in the selection of solar window film sheets. In this research, a multi-criteria decision-making approach was applied to compare three different types of window film sheets, Silver 35, TrueVue 15, and Sterling 40, to aid in selecting the most suitable window film based on the United Arab Emirates market. The primary aim of this work is to provide decision-makers with a structured approach to enhance their choices for selecting window film sheets. The methodology employed involves evaluating various criteria, including visible light transmittance, solar energy rejected, energy transmittance, energy absorptance, cost, glare reduction, visible light reflectance interior, and fade reduction. These criteria are assessed using the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The results demonstrate that Sterling 40 is the best choice followed by Silver 35. Based on the final TOPSIS results, the difference between the scores of these two window film sheets was not significant, while they were far from the score of TrueVue 15.

Optimizing Bus Stop Environments: Analysis of Sun Glare Reduction with Green Elements in MLS and GPR Data

Optimizing Bus Stop Environments: Analysis of Sun Glare Reduction with Green Elements in MLS and GPR Data

Simulation-Based Evaluation of the Impact of an Electrochromic Glazing on the Energy Use and Indoor Comfort of an Office Room

Electrochromic glazing alters its optical properties in the absence/presence of an electrical charge, varying from clear to dark to control daylighting and solar heat gains. This study aims to evaluate the impact of an electrochromic glazing, with indoor glare or temperature control, on the energy performance and thermal and visual comfort of an office room under three European climates, using a calibrated simulation model. The novelty of the paper lies in its combined performance assessment, using different standards and metrics. The results showed reduced climatization energy requirements with temperature control, but significantly increased artificial lighting energy use. Glare control achieved useful illuminance levels during 74–80% of working hours. Concerning temperature control, working hours within thermal comfort increased (21–43%) under a free-float regime. Moreover, the performance of this glazing was compared to that of a clear glazing with/without a reflective film and a thermochromic glazing for different solar orientations. The electrochromic glazing with glare control showed the highest energy savings (14–36%) for a western orientation, and the lowest negative impact on daylighting for a northern orientation. The best glare reduction was achieved with the reflective film. Considering the free-float regime, the electrochromic glazing, with temperature control, showed the highest increase in working hours within thermal comfort (6–9%) for a western orientation.

Optimal Design of Tilted Building Envelope Considering Air Conditioning Energy Demand, Daylight Utilization and Glare Protection—Case Study

An important energy-saving method to optimize building envelope design is the integration of local climate characteristics. This study attempts to find sloped facade configurations to balance air conditioning energy demand and daylight utilization for four directions in an area with a hot climate. Tilt angle dependence of the air conditioning energy demand, useful daylight illuminance (UDI) and daylight glare index (DGI) are selected to investigate the acceptance thresholds of the tilt angle. The final facade’s configuration is achieved by employing the graphical optimization method. An acceptable solution that balances better daylight performance and less energy consumption by air conditioning is developed. Due to the considered city being located in a low-latitude area with great daylight availability as well as a fully dimmable light control strategy, unbearable glare reduction can be achieved by benefiting from the sloped facades, without necessarily sacrificing much usable daylight. Meanwhile, there is no obvious increase in the demand for lighting energy consumption, and a good outward view is preserved. The sloped rather than vertical facade provides natural solar shading to the east-, south- and west-oriented windows while allowing low-angle winter solar heat to warm the building space. Tilt angles between 35°and 40° are preferred for the east facade, and smaller tilt angles of between 30°and 35° are recommended for the south facade. Larger tilt angles of between 40°and 45° are preferred for the west facade. However, the north-facing facade’s outward tilt would cause an undesirable increase in air conditioning energy demand. The annual air conditioning energy demand of the east-, south- and west-facing space is found to separately decrease by 7.1%, 7.3% and 9.9%, respectively, benefiting from the sloped facades.

Optimizing daylight in west-facing facades for LEED V4.1 compliance using metaheuristic approach

This study introduces an optimized design approach for west-facing room façades to improve daylighting while adhering to LEED v4.1 sustainability criteria. Employing parametric modeling, metaheuristic optimization, and validated daylight simulations, the research highlights the African Vulture Optimization Algorithm's success in achieving 100% LEED compliance and superior performance over random models in daylight sufficiency and glare reduction. Light-colored materials and transparent glazing emerged as beneficial for LEED points. Despite computational limitations and the need for empirical validation, this method offers architects versatile and sustainable design solutions. Comparative analysis reveals the algorithm's strong performance, although opportunities exist for refinement. Future research directions include contrasting this algorithm with other optimization methods, focusing on empirical backing, assessing environmental and human-centric impacts, adapting to varied building types and conditions, and examining diverse geographical and material factors. This work advances daylight-integrated façade design, suggesting a more comprehensive framework for building performance optimization.

Sunglass tint does not impact the indoor catching performance of cricket fielders.

Sunglasses are worn by outdoor athletes such as cricketers for many reasons, including comfort and glare reduction, which may help to improve vision. Anecdotally they are purported to have performance-enhancing benefits, but there is a lack of evidence for this. Further, it appears that fielders are the only position in cricket who wear sunglasses. Therefore, this study aimed to compare the catching performance of fielders when wearing three different colour sunglasses tints during an indoor, laboratory-based experiment. Twenty-one male cricketers currently playing for a university or amateur provincial teams in Makhanda, South Africa, who were non-habitual sunglass wearers, were recruited for this study. An optometrist administered pre-screening tests. Players had four testing sessions during which they wore a different colour tint at each session indoors (clear, blue, G30 (rose), and red). Players were required to catch 18 balls projected from a bowling machine. The number of balls caught, as well as the quality of the catch, was recorded. At the final session, they were asked which tint they thought was best. Pre-screening tests showed that the red lens was best for contrast sensitivity and stereopsis. During data collection, sunglass tint did not affect catching performance. The players perceived the red lens as the worst and the G30 as the best. It can be concluded that catching performance indoors is not affected by tint colour.

Multi-criteria evaluation of daylight control systems of office buildings considering daylighting, glare and energy consumption

Through the coupling of glazing and shading systems, daylight control systems (DCSs) are formed. By using such systems, the visual comfort of occupants as well as the energy efficiency of the building can be greatly enhanced. Further, these systems are imperative in climates where excessive and uncontrolled daylight may result in significant increases in cooling loads and glare, as well as a decrease in visual efficiency. There is, however, an inherent contradiction in the design of DCSs. This is due to the way daylight affects indoor spaces in that, despite being beneficial for visual comfort, it can also be detrimental to energy efficiency and glare, or vice versa. Therefore, to achieve a near-optimal indoor environment, daylighting should be increased while glare and energy consumption should be reduced. In this study, 155 unique DCSs are evaluated in cardinal and intercardinal orientations using a multi-criteria decision-making (MCDM) method. For each design alternative, daylighting, glare, and energy simulations are conducted using UDI, sGA, and EUI as performance metrics. The MCDM method, then, ranks the utility of the DCSs by aggregating the weighted simulations results. Results indicate that the coupling of “reflected horizontal louvers” with “vacuum glazing” is the most frequently used best design alternative regardless of orientation. Further, it is revealed that among all the top-ranked DCSs in each orientation, those in the south orientation are found to be the most effective at improving daylighting, glare, and energy efficiency simultaneously. It is also found that when an architectural design is intended to achieve daylighting, glare reduction, and energy efficiency simultaneously, a south-facing building is the optimal choice.

Aniridic scleral fixation of intraocular lens: The answer to vision loss with photophobia!

Aniridia is defined as missing iris tissue which can be partial, subtotal, or total. Characteristic clinical symptoms include photophobia and decreased visual acuity due to an increased light perception. In addition to this, disturbing cosmetic problems are prevalent. Even after implantation of an intraocular lens, patients often tend to be unsatisfied. The answer to this problem lies in the implantation of an aniridic scleral fixation of intraocular lens (SFIOL), which has a central optical axis that acts as the refractive lens and a peripheral rim of a hyperpigmented area that mimics the iris and hence reduces photophobia. The purpose of the video was to demonstrate the use of black diaphragm intraocular lens (BDIOL) implantation, its surgical steps, and its outcomes. We report one such case where a young patient presented with post-traumatic aniridia with subluxated total cataract and spillover vitreous hemorrhage. He was subjected to a vitrectomy, cataract removal, and placement of an aniridic SFIOL with prolene 9-0 using the four-point fixation method. This gave an extremely gratifying outcome and solved both problems, that is, vision and photophobia. Highlight: Before implantation of the SFIOL, the patients had reduced visual acuity from aphakia and intolerable glare from aniridia. In this case-based approach and with relevant example, we tried to provide a solution for tricky scenarios like co-existing traumatic cataract and traumatic aniridia. The patient showed improved visual acuity and marked glare reduction after black diaphragm SFIOL implantation. https://youtu.be/atl60WetFsM.

Enhancing building thermal performance in Saudi's extreme climates through reversible smart insulated window glazing: Laboratory-scale experiments

The positioning and type of double-glazing layers effectively regulate heat gain and heat loss during both summer and winter seasons. This study aims to evaluate the thermal performance of the Reversible Smart Insulated Window Glazing (RSIWG) system in controlling solar heat gain in Saudi Arabia's extreme climates. Laboratory-scale experiments and analytical methods were employed to examine four glazing scenarios, each characterized by the positioning and states of the Polymer Dispersed Liquid Crystal within the insulated double-glazing system. The findings indicate that SIWG-colo significantly reduces heat gain by 26 % and 78 %, respectively, compared to double insulated glazing and clear glass, making it suitable for cooling seasons. On the other hand, SIWG-rev-colo exhibits slightly less heat loss, rendering it suitable for heating seasons, especially in situations where solar radiation is absent. The RSIWG system provides added advantages such as dynamic privacy protection, glare reduction, and flexibility in response to daylighting and outdoor connection. Further research is recommended on multi-layer PDLC incorporating vacuum glass.

Development of a Patient-Reported Outcome Measure to Assess Symptoms Associated with Cataract Surgery and Intraocular Lens Implants

To develop a standardized patient-reported outcome measure of visual perceptions and symptoms for implanted premium and monofocal intraocular lenses (IOLs). Observational study before and after IOL implants to assess the measure and symptom experience. Adults scheduled for binocular implantation of the same IOL type completed the survey at baseline prior to surgery (n = 716) and postoperatively (n = 554). Most respondents were female (64%), White (81%), 61 or older (89%), and had some college or more education (62%). Administration was by web survey with mail follow-up and phone reminders. Frequency, severity, and level of symptom bother in the last 7 days for 14 symptoms: (1) glare, (2) hazy vision, (3) blurry vision, (4) starbursts, (5) halos, (6) snowballs, (7) floaters, (8) double images, (9) rings and spider webs, (10) distortion, (11) light flashes with eyes closed, (12) light flashes with eyes open, (13) shimmering images, and (14) dark shadows. The median correlation among having 14 symptoms at baseline was only 0.19. Mean uncorrected binocular visual acuity improved from a preoperative value of 0.47 logarithm of the minimum angle of resolution (logMAR; Snellen 20/59) to a postoperative value of 0.12 (20/26) and best-corrected binocular visual acuity improved from 0.23 logMAR (20/34) preoperative to 0.05 logMAR (20/22) postoperative. The most bothersome symptoms were reduced after surgery: preoperative/postoperative glare (84%/36%), blurry vision (68%/22%), starbursts (66%/28%), hazy vision (63%/18%), snowballs (55%/17%), and halos (52%/22%). All symptoms decreased significantly (P < 0.0001) from before to after surgery except for dark crescent-shaped shadows (4%/4%). The percentage of symptoms rated as quite a bit or extremely bothersome declined from before to after surgery except for dark crescent-shaped shadows (29%/32%): blurry vision (54%/15%), snowballs (52%/14%), glare (49%/15%), and halos (46%/14%). Having monofocal IOL implants was associated with significantly more reduction in halos, starbursts, glare, and rings and spider webs, but less improvement in self-reported general vision. This study provides support for the 37-item Assessment of IntraOcular Lens Implant Symptoms (AIOLIS) instrument for use to assess symptoms and general perceptions of vision in clinical studies and clinical care. Proprietary or commercial disclosure may be found after the references.

Industrial applications of sol-gel derived coatings.

Sol-gel derived coatings have many practical applications in different industries. In this paper, HI-GARD® hard coat, multi-layer antireflective coatings, and an anti-glare coating with organic particles are described. Optical and mechanical performances of these coatings are discussed in addition to adhesion properties. The HI-GARD® hard coat was dip or spin coated from a sol by hydrolyzing alkoxysilanes with water in an acidic condition. The hard coat acts as a protective coating for optical lenses with excellent optical properties with a Bayer ratio of 4.8 and an adhesion of 5B. The multi-layer antireflective coatings were prepared by incorporating titanium oxide sol into the HI-GARD® hard coat solution to obtain different layers by spin-coating with tunable refractive index. These two-layer or three-layer antireflective coatings increase transmittance by at least 3% compared to an uncoated glass substrate. Anti-glare coatings were spray-coated at room temperature on glass substrates by embedding cationic or anionic polystyrene particles in an acid-hydrolyzed silane sol. The anti-glare coating with organic particles can provide a significant glare reduction with a haze value of up to 13% for display surface without sparkling. In addition to these transparent coatings, non-transparent sol-gel derived coatings such as a sol-gel non-stick coating for cookware and bakeware, and two zinc-silicate protective coatings hydrolyzed from a silane with addition of zinc dusts for corrosion protection are also discussed briefly. The schematic structures of the hard coat on CR-39® substrate, three-layer AR coatings on glass substrate, and organic particle embedded anti-glare coatings on glass substrate, and their respective transmittance or reflective curves.

Numerical Shear Buckling Investigation of GLAREs with Initial Delamination

GLAREs as hybrid materials are widely employed members of fibre metal laminates (FMLs) in aerospace structures. Delamination is one of the most critical failure modes that happen during the manufacturing or service life, decreasing the stability and reliability of the GLARE laminates. Accordingly, this study presents an investigation of the shear buckling phenomenon, a very common load condition in aerospace structures, of different GLAREs, differentiating in the laminate layout, containing embedded delamination by the FEM ABAQUS software. The cohesive zone interface elements of FM94 are considered to evaluate the delamination growth. This parametric study displays the effect of the initial delamination dimension and its position as well as the thickness of the metal layer on the stability of GLARE laminates. The model predicts the stability reduction of GLARE laminates as a function of the delamination radius and its position. The results show that aluminium layer reinforcement increases the overall stiffness and shear buckling capacity and the specimen’s resistance to delamination growth. In addition, the produced results in this study can encourage designers to select appropriate GLARE grades based on the intended application, such as different shear loading conditions and available raw materials.

Energy saving through building automation systems: Experimental and numerical study of a smart glass with liquid crystal and its control logics in summertime

Smart glass technology is promising building envelope solution for Responsive Building Envelopes (RBEs) if smart communities with zero net emissions must be achieved. This solution could lead to energy saving and a thermal comfort improvement, but also a reduction of possible glare, improving the visual comfort. On the basis of an extended literature analysis there are some smart window technologies, such Electrochromic ones, most mature at research level, showing a large impact in the reduction in cooling demand. On the other hand, these solutions have some issues, like the long switching period or the alteration of indoor perceived colours. An example of promising alternative to Electrochromic technology could be the liquid crystal device, which performances have not been enough investigated in the current literature. In this context the purpose of the present study is to develop a deep investigation, thus numerical and experimental, of a full-scale electric-driven window (liquid crystal technology) installed in an outdoor test-room, in order to evaluate the effect of its usage on energy consumption and daylight control. Based on continuous monitoring, a numerical model of HVAC-building system with smart window was developed and calibrated. It allowed to carry out a sensitivity analysis on the energy demand by considering all window exposures, the window control logic (based on illuminance level or indoor air temperature), different climate zones (Benevento, Athens, London and Cairo) and the window to wall ratio (18% or 100%) also. Comparing the results with a static window, for all exposures and all climates, the dynamic window could reach an energy saving, up to −17%.

Experimental analysis of solar light pipes compared to direct and light-well daylight transmission methods for indoor spaces

Effective use of natural daylight in indoor spaces contributes to reduced energy consumption in electrical systems as well as improved occupants' visual comfort. Present experiments conduct image recording of three-floor level laboratory building models designed for solar daylight transmission through four different methods (simple window, light-well, and solar light pipes using two different flooring materials) under two incident light angles. The image-based analysis of the probability density functions associated with indoor illumination quantifies the qualitative visualizations of different daylight transmission techniques. It is found that using proper diffuser material for simple windows (direct method) may sacrifice nearly 2% of the light intensity, while significantly enhancing the distribution. In addition, the use of light pipes has provided the best distribution in the environment, which, in some cases, has improved the uniformity of light up to 15.7% compared to other methods. It is shown that the visual discomfort in direct and light-well methods due to the glare formation and indoor lighting non-uniformity under inclined incident light angles can be prevented by using light transmission tubes. At the same time, the use of light tubes at vertical angles improves intensity by up to 17.5% in addition to enhanced light distribution. Present findings based on statistical analysis clearly highlight the significance of quantifying the indoor ambient light distribution in addition to the overall intensity of light. From a practical point of view, the present study suggests that the proper implementation of light transmission tubes results in enhanced uniformity and visual comfort of indoor lighting due to glare reduction while providing sufficient light intensities comparable to other daylight transmission methods. For improved solar light pipe designs, it is also suggested to consider their efficiency dependence on the tube length as well as flooring materials.

Impact of Different Shading Devices on Daylight Performance and Visual Comfort of A Four Opening Sides' Reading Room In Rasht

Daylighting has become an essential feature in libraries since it can boost productivity, well-being, and energy savings. It is crucial to prevent discomfort glare irritation while maintaining the quality of view, and daylight demands. This study compares four different shading systems on all fronts of a reading room. Shading devices include a Perforated Solar Screen (PSS), besides three Venetian Blinds typologies (exterior, interior, and exterior integrated with overhangs) are generated considering various parameters. The 60-min time step for an entire year is used to find out the worst dates for glare analysis in different positions for Rasht, Iran. The findings of Daylight Autonomy (DA), Useful Daylight Illuminance (UDI), Daylight Glare Probability (DGP), and Quality of View (QV) depict that PSS is ineffective at glare reduction but is adequate for annual metrics and view quality. Moreover, Venetian Blinds in every three typologies are sufficient to deal with glare problems on most dates, despite differences in their characteristics being reported. Annual metrics and Quality of View in these cases, depending on variables, are changeable.

Optimization of classroom design: use of natural light for visual comfort in Villa María, Argentina

The present work addresses the problem of natural lighting in educational buildings, focusing on the study of natural lighting strategies that contribute to reaching recommended levels of lighting comfort in classrooms, correct light distribution and glare reduction. In this framework, a building on the campus of the National University of Villa María, Córdoba, Argentina, was analyzed in which the behavior of natural lighting was evaluated using simulation models and in situ measurements. The work was complemented by evaluating the Daylight Glare Probability (DGP) index: verifying the occurrence of glare. The diagnosis showed excess lighting at points close to openings, insufficient lighting at points far from them, low levels of uniformity in the distribution of natural lighting and intolerable glare thresholds. Consequently, a new arrangement of the classroom was proposed, incorporating elements for the redirection of sunlight and its performance was verified. The results of the proposal showed important differences. A significant reduction in lighting levels was achieved, reaching levels of visual comfort for classrooms (300-500 average lux), improvements in the uniformity of natural light, with its consequent verification according to standards, and a significant reduction in glare levels due to penetration direct sun.

Daylighting evaluation in deep plan office buildings with OPV windows through simulation on Radiance

This research aims to evaluate the OPV window (OPVW) potential application in a deep-plan multi-storey office building, in order to verify its contribution to indoor daylighting quality. OPVW is a cost-effective technology with reduced environmental impact, suitable for application in a multi-story office building due to its potential to adapt to different architectural configurations, lightness and transparency, etc. In an earlier study developed by the authors, an experiment was conducted with a generic office room scale model. Three window materials were compared under real sky conditions (overcast and clear): 3 mm single glass (A scenarios); single glass with OPV (B scenarios); and single glass with application of solar control film (C scenarios). In the present study the same parameters from the experiment were used as input for simulations on Radiance, whose results were compared to previous (work plane illuminance, Daylight Factor and model interior photographs). We found similarities between them. Thus, further results were produced: isolux curves, Daylight Glare Index and render images. The rendered images show a brighter view at A scenarios, and at B and C scenarios. Even if average illuminance is reduced, a better daylight distribution and a reduction in glare are achieved. DGI indicates perceptible glare for some of A scenarios. On the other hand, at most of B and C scenarios, glare was below the perceptible range. Furthermore, the scenarios with OPVW (B scenarios) still show one more advantage: the energy production for artificial lighting when illuminance values are not sufficient.

Microscale surface texturing on nonplanar surface of diffusion lens for anti-glare LED light

In this study, we present the fabrication technique and characterization results of a concave-bottom rod lens (CB-RL) covered with microstructures to diffuse the Light-emitting diode (LED) light for anti-glare. The spherical concave bottom of the rod lens was designed based on a basic refraction theory and was fabricated by using the hyper-elastic deformation characteristics of polydimethylsiloxane film to form microstructures on the nonplanar surface. The rod lens mold and microstructure mold were prepared via the metal cutting process and photoresist reflowing process, respectively. In the experimental study, a CB-RL with and without microstructures was fabricated and compared. A CB-RL mounted on an LED effectively changed the isomeric luminous intensity profile into a batwing-shape profile. The reduction in discomfort glare induced by a single LED was characterized by comparing the uniformities of the luminous intensity between the bare and proposed lens-mounted LEDs. The full width half maximum (FWHM) value of the luminous intensity was increased from 50.9% to 71.4%, and the maximum-to-minimum ratio of the luminous intensity was reduced from 3.91 to 1.94. For a light bulb consisting of eight LEDs, the FWHM value and maximum-to-minimum ratio of the luminous intensities were improved from 38.0% to 55.0% and from 10.96 to 6.96, respectively.