Levels Of Glare Research Articles

ANALYSIS OF GLARE IN CLASSROOMS UNDER ABNT NBR 15.215-3:2024 AND CONSIDERING USER'S PERSPECTIVE

The new version of the Brazilian standard for Daylighting - Part 3 - Procedures for the evaluation of daylighting in indoor spaces, ABNT NBR 15.215-3:2024 proposes assessing the quality of lighting in indoor spaces based on new parameters, including the phenomenon of glare. Glare caused by daylight can affect the performance of users in educational spaces. This study aimed to examine the occurrence of daylight glare in a classroom at the Federal University of Minas Gerais using computer simulation with the ClimateStudio plug-in for Rhinoceros software based on methodologies proposed in the Brazilian standard along with questionnaires. Users' perception indicated that the level of glare might be higher than predicted by the simulations. It was concluded that control devices are essential to mitigate discomfort caused by glare in daylit spaces.

The overall performance of a novel semi-transparent photovoltaic window with passive radiative cooling coating – A comparative study

Semi-transparent photovoltaic (STPV) glazing is a promising building integrated photovoltaic (BIPV) technology for converting traditional windows into on-site energy-producing building components. Besides electricity generation, there is also an urgent demand to enhance the thermal management of STPV glazing. Passive radioactive cooling paint is an emerging nanomaterials technology that shows great potential to reduce the painted surface temperature. Aiming to further promote the PV window’s energy efficiency, this study designed and investigated a novel coated semi-transparent photovoltaic (CSTPV) glazing supplemented with highly transparent passive radiative cooling coating. In addition, the STPV/CSTPV’s impacts on indoor visual environments were investigated, especially on the rarely studied aspect of interior colour rendering performance.This paper employs a combination of numerical simulation and experimental measurements to comprehensively assess these innovative glass systems in terms of electricity generation, thermal performance, daylighting efficiency, and the impact of color on the indoor environment. The results indicate that the CSTPV windows can significantly reduce the heat gain rate by about 15 % and achieve excellent electricity generation, with an annual output approximately 3 % higher than that of STPV windows. Despite the radiative cooling coating, CSTPV glazing maintains a level of daylight illumination comparable to that of STPV glazing, with glare levels remaining within acceptable limits. Furthermore, the study emphasizes the effects of CSTPV and STPV on the indoor Color Rendering Index (CRI) and Correlated Color Temperature (CCT) performance. All samples measured have CCT values within the range of neutral light, and CRI values exceeding 96, demonstrating satisfactory high-quality indoor lighting conditions. This research shows that CSTPV and STPV glass technologies not only significantly enhance the energy efficiency of buildings but also provide a scientific foundation for sustainable development in architectural design.

Solar responsive building glazing: Experimental analysis of the impact of photochromic glazing on indoor thermal and luminous conditions

The application of films on conventional glazing aims at increasing the glazing performance by reducing energy needs and increasing indoor comfort. Photochromic films in particular can alter their optical properties due to a chromatic change in response to solar radiation, allowing for reduced glare levels and solar heat gains. However, despite the potential of application, this refurbishment solution is still poorly explored. Therefore, the main purpose of this work was to experimentally evaluate the thermal and luminous performance of a double glazing with and without a photochromic film installed, using two office rooms in Lisbon as case study. An extended field experimental campaign was conducted simultaneously in both offices, where temperature, solar radiation and illuminance levels were collected. The key contribution and novelty of this research lies on the experimental assessment of the thermal and visual comfort conditions with the photochromic film under real-occupancy. Even though the photochromic film significantly increased the surface temperatures of the glazing, the indoor air temperature was not negatively affected, with an increase up to 14 % of working hours with comfortable temperature during the heating period. Illuminance levels on vertical/horizontal plane were reduced by 24/36 % in the presence of the photochromic film, when compared to the clear glazing without film, resulting in an increase of 7 % of working hours with useful illuminance during the heating period, and large areas in the office room with imperceptible daylight glare levels when facing the glazing system. The impact of the film was less noticeable during the cooling period.

Comparative Validation of Light Environment Simulation with Actual Measurements

The quality of indoor lighting significantly influences human well-being, emphasizing the need to integrate lighting planning into the architectural design process. To optimize indoor lighting conditions, light environment simulations are commonly employed. While much of the relevant literature clearly shows that simulations are widely used to predict lighting environments, there is limited active research validating these simulations. Therefore, this study aimed to assess the alignment between actual measurements and simulations, specifically focusing on daylight-induced glare. To achieve this, a comparative analysis and verification of glare levels between simulations and actual measurements were conducted that accounted for glare location and direction. Disparities between the simulated and measured glare levels were revealed contingent on the glare location and direction. These variations primarily arose from the simulation’s utilization of a fisheye field of view (FOV) for glare measurement. To improve the accuracy of glare analysis in simulations, it is advisable to follow the standards related to the human perception of glare, such as the human field of view (FOV), instead of solely depending on a fisheye FOV. The study’s limitations include challenges in environmental replication, minor measurement errors, and tree branch shading interference. Despite the potential for simulations to not replicate temporary glare effects, consistent differences with actual measurements indicate that the fisheye FOV was a key contributing factor.

A cross-climate assessment of the visual and energy performance of flexible photochromic films for in-situ window retrofits

Driven by their low thermal resistance and static transmittance to solar radiation, existing static clear windows are often considered the least-efficient components in the building envelope, driving the heating and cooling demands and compromising the thermal and visual comfort of building occupants. Hence, window retrofit technologies that utilize innovative coatings are critical for enhancing energy efficiency and indoor daylight quality in the existing building stock. In particular, dynamic photochromic window films that reversibly modulate solar gains responding to the abundance of ultraviolet radiation are promising but received little attention. In this paper, five commercial flexible photochromic window films were experimentally characterized, and their energy and daylighting performance were numerically and parametrically evaluated in a representative office with different window configurations and orientations across six representative cities with a diverse range of climates. This is one of the first works dealing with photochromic window films as a retrofit technology. The results show that the films exhibit excellent colour-rendering and cyclic stability with rapid switching/bleaching rates. In addition, annual energy savings in the 1% − 4% range were observed for low window-wall ratios, reaching 10% − 14% in cooling-dominated climates with lower latitudes using PC-1, which resulted in the most significant cooling energy savings. Although the film influenced the quantity of light, resulting in lower daylight autonomy, improvements in the useful daylight illuminance and significant reductions in discomfort glare levels were the major benefits of retrofitting existing double-glazed clear windows with the photochromic film.

Subjective and Simulation-Based Analysis of Discomfort Glare Metrics in Office Buildings with Light Shelf Systems

Glare is a kind of physiological phenomenon that influences occupants’ visual comfort. Discomfort glare scenes in comparison to other levels of glare have been difficult to estimate and need accurate and reliable metrics. In contemporary architecture, the glass façade is so popular since it can remarkably minimize energy consumption in buildings and maximize daylight utilization as a natural energy. However, it is necessary to consider occupants’ visual discomfort due to the daylighting glare risks during the initial stage of design. Since the measured glare metrics should have an acceptable correlation with the human subject data study, the agreement on the glare indices is complicated. This paper presents a comparison between subjective and simulation-based analysis of discomfort glare metrics in offices with a light shelf system. The discomfort glare metrics considered in this study include Daylight Glare Index (DGI), CIE Glare Index (CGI), Visual Comfort Probability (VCP), Unified Glare Rating (UGR), and Daylight Glare Probability (DGP). The parallel comparison was conducted by using simulation and questionnaire surveys to determine which criteria are more useful under different conditions. According to the findings, DGP yields the most reliable results in different levels of glare based on the subjective analysis and VCP has the lowest accuracy in each stage. UGR also has the highest accuracy rate for evaluating perceptible glare, DGI is applicable for assessing imperceptible glare, and CGI can be an acceptable index for approximating intolerable glare. The study results significantly reduce the complexity of the problem and can provide useful guidance for designers to select the most reliable glare metric based on climatic conditions.

Comparing microscope light-associated glare and comfort between heads-up 3D digital and conventional microscopes in cataract surgery: a randomised, multicentre, single-blind, controlled trial

ObjectiveTo compare subjective levels of comfort and visual experiences related to microscope light in patients undergoing their first cataract surgery with topical anaesthesia using a digital microscope (the NGENUITY three-dimensional...

Study on the risk assessment of light pollution based on entropy weight method-TOPSIS model

In the process of rapid human development, artificial light has gradually increased. People use artificial light more consider light to bring us benefits, but light pollution and the use of light at the same time harm human beings, even to the point of endangering human health and affecting the ecological environment. The problems caused by light pollution are waiting to be solved by us and all human beings together. In this paper, regional vulnerability (e.g., regional development level, population, biodiversity, etc.) is considered. Together with the intensity of pollution sources (e.g. road glare level, light hours, light violation level, etc.), the risk level of light pollution is determined. The risk level model of light pollution was established by calculating the weights of each index using TOPSIS entropy weighting method and hierarchical analysis method. The natural interruption point method was used to classify the risk level of light pollution into level I, level II, level III, level IV, and level v. The risk level model of light pollution was applied to four regions. We derived the risk level as level IV for urban communities, level II for protected land and suburban communities, and level II for rural communities.

A study of daylight glare evaluation with prism daylighting redirecting fenestrations

This study explored daylight glare evaluation for Prism Daylight Redirecting Fenestrations (PDRF) with young adults. HDR photography was employed to calculate daylight glare indices, and subjective response was measured by continuous and discrete scales. The statistical results showed that Daylight Glare Probability (DGP) correlated strongly with subjective glare perception and was more robust than Daylight Glare Index (DGI) with PDRF systems. In addition, subjectively estimated glare tolerance time was proposed, and the research results revealed that subjectively estimated glare tolerance time strongly correlated with subjective responses. Vertical eye illuminance as a daylight glare index for PDRF was also investigated. Three Ev thresholds of different glare perception levels were determined based on the confidence intervals analysis. Three Ev values on four categories of perceived glare levels with PDRF for young adults in classrooms under subtropical skies were identified as 2300 lx, 3000 lx, and 4300 lx, corresponding to the thresholds of imperceptible-perceptible, perceptible–disturbing, and disturbing-intolerable, respectively.

Contrast-based evaluation of the reflected daylight glare on the blackboard in a classroom with complex fenestration systems

Visual comfort within a classroom determines students’ concentration, productivity and well-being. The existing glare-based metric (e.g. Daylight Glare Probability, DGP) cannot reveal the visual comfort level when students look at notes written on the blackboard in a daylit classroom. Contrast-based metric has been proven as a more appreciate method for evaluating the vision within the area of a blackboard. The aim of this article is to explore the applicability of a contrast-based metric in evaluating classroom daylight design. The contrast-based metric was proposed based on the statistical results of a previous study on disturbing reflections on a blackboard. The evaluation method using contrast ratios within the blackboard area was established based on RADIANCE simulation and validated against experimental measurements. Bidirectional scattering distribution function (BSDF) data was used to model the complex fenestration systems (CFS) in the studied classroom. The validation results show that the error of simulated contrast ratio is within 17%. When using the contrast-based metric for assessing the studied classroom with different fenestration designs, the simulation results indicate that applying vertically placed daylight redirecting louver can significantly improve the contrast performance while maintain the daylight availability, providing design guidance for fenestration systems of classrooms. The simulation also illustrates that using DGP in a classroom leads to an underestimation of the glare level. This study contributes to expanding the knowledge on visual environment evaluations of classrooms, demonstrating the capacity of using contrast-based metric on determining disturbing glares in a classroom daylight design.

IOL glistenings and disability glare

AbstractGlistenings are small fluid‐filled microvacuoles that appear within the intraocular lens (IOL) optic when it is placed in an aqueous environment. Subsurface nanoglistenings are much smaller fluid‐filled gaps from the surface of the optic of the IOL and they may give the IOL surface whitish coloration when the light is directed at the IOL at the angle of incidence of 30° or greater. It has been proposed that the optical quality of an IOL is not significantly affected by the level of glistenings. However, glistening was shown to degrade vision by inducing glare symptoms (straylight) rather than by lowering visual acuity; straylight elevation demonstrates a proportional relationship with the number of glistenings. Retinal straylight, even presenting in low levels, can cause increase in halo size, elevation in luminance detection threshold, and reduction in contrast sensitivity, being a reason for persistent visual complaints. The magnitude of retinal straylight can be clinically determined by the level of disability glare. Moreover, glistenings are not unique to adults and have been reported in paediatric patients Thus, patients having undergone cataract surgery in childhood should undergo a periodical ophthalmic follow‐up for evaluating visual quality and disability glare, and subsequently as determined by grade of glistenings.

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.

Contrast Sensitivity Changes after Phototherapeutic Keratectomy in Heterozygote Granular Corneal Dystrophy Type 2

Purpose: Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. In granular corneal dystrophy type 2 (GCD2), opacity of the corneal stroma causes deterioration in visual function. We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients.Methods: This study included 22 eyes of heterozygote GCD2 patients. The visual acuity and contrast sensitivity were measured before and after PTK. The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd).Results: The contrast sensitivity increased after PTK at 1.5 and 3 cpd in mesopic and photopic conditions with G0-2 glare (p < 0.05). At 6 cpd, the contrast sensitivity increased in the mesopic condition with G1 glare, and in the photopic condition with G0-2 glare (p < 0.05). However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK.Conclusions: In GCD2 patients, the contrast sensitivity increased significantly after PTK. The vision of GCD2 patients, which is decreased due to corneal opacity, is improved after PTK.

An empirical investigation of disability glare and visibility level during driving inside very long road tunnels: A case study

IntroductionDisability glare from lighting systems is considered to be one of the main causes of accidents in road tunnels. The present study aimed to investigate the estimated method of disability glare, the experimental method of visibility level, overall uniformity, and longitudinal uniformity of the tunnel lighting system during driving inside very long road tunnels. MethodsThe disability glare in different road sections of the tunnel was estimated based on the threshold increment (TI) recommended by the CIE 88–2004 method. For visibility level measurements, a standard 20 × 20 cm barrier with a reflection coefficient of 20% was placed in different road sections of the tunnel, and the barrier visibility level was recorded as a self-reported questionnaire by 40 professional drivers in four age groups. The estimated method was used to compare the disability glare data with the experimental method of visibility level. Also, in order to investigate the effect of overall uniformity and longitudinal uniformity in different road sections of the tunnel on visibility level, according to the IESNA LM-71-96 and IESNA LM-50-99 standards, these factors were also examined. ResultsFor the age groups of 19, 40, 64, and 80 years, respectively, the TI in the north lane in road sections 5 (17.7%, 18.4%, 28.65%, 44.3%), 8 (28%, 31.3%, 41.2%, 52.7%), and in the south lane in road section 4 (16.8%, 17.4%, 24.2%, 41.3%) had a higher disability glare than the CIE88 standard (TI = 15%). The results showed that visibility levels were reduced in sections of roads with higher disability glare. Also, in road sections 5 and 8 of the north lane and road section 4 of the south lane, longitudinal uniformity was equal to 0.53, 0.57, and 0.5, respectively, which is less than the CIE88 recommended (0.6),Therefore, when comparing longitudinal uniformity with visibility level, it showed that visibility decreased significantly in these road sections. However, although overall uniformity was reported to be less than standard in most road sections, no correlation was observed between overall uniformity and visibility level. The estimation method also showed that the level of disability glare in drivers’ increased with age, which was associated with a decreased visibility level in the experimental study. ConclusionThere is an inverse relationship between the theoretical equations of disability glare and the decreasing visibility level in different road sections of the tunnel. A direct relationship was observed between visibility level and longitudinal uniformity. But this relationship between visibility level and overall uniformity was not observed. Also, age had a significant effect on disability glare in different road sections of the tunnel.

Analysis of dynamic louver control with prism redirecting fenestrations for office daylighting optimization

Daylighting with redirecting complex fenestration system (CFS) may improve the indoor luminous environment. This study is to explore the strategies for controlling louver tilts of dynamic micro-prism film louvers corresponding to different solar incident angles, to optimize the work-plane illuminance (WPI) at the middle/back zone of the analyzed large-depth office, based on the simulation results of daylight filtering. To reduce the rotation frequency of the slats, several slat tilt angles were tested to adapt to the changes of different sun incident angles. The study compared the annual daylight performance and glare levels of the three CFSs with dynamic metal louvers, dynamic micro-prism film louvers, and micro-prism film, using the Five-phase method (5-PM). The results showed that the dynamic micro-prism film louvers combined with the proposed control strategy provided a better daylighting luminous environment, regarding the improved useful daylight illuminance (UDI) at inner space, and yielded less glare occurrence rates at space close to windows, compared with dynamic metal louvers and double glazing. Furthermore, the study proposed the combined dynamic louvers that consisted of micro-prism film slats and metal slats to reduce the possible glare on the premise and improve the indoor illuminance at the inner space. The simulation results showed that the combined dynamic louvers could reduce the discomfort glare occurrence rate by 68.9%, compared to the discomfort rate with double glazing at the front zone; UDI300-2000 lx of the combined louvers could be improved by 23%, compared with that of double glazing at the front zone. Compared with the metal louvers with similar low glare occurrence rate, the combined louvers could improve UDI100-300 lx at front/middle/back zones by 7.9%, 29.1%, and 2.9%, respectively, and UDI300-2000 lx by 40.0%, 11.7%, and 5.7% at these zones, respectively.

Study on the Influence of Opposing Glare from Vehicle High-Beam Headlights Based on Drivers’ Visual Requirements

The anti-glare facilities in median strips are designed to block opposing headlights in order to avoid disability glare, but a large amount of headlight leakage results in uncomfortable glare, to the point that drivers can barely detect dangerous obstacles or road conditions. This paper aims to explore the glare range under high-beam headlights on drivers’ visual requirements. Based on an analysis of the mechanism of headlight glare, this paper proposes a subjective headlight glare scale, and classifies glare discomfort into two categories: interference glare, and acceptability glare. Combining the scales, 24 drivers and a standard light-emitting diode automotive headlamp were used to conduct glare effect tests. The size of the laboratory that closes to scotopic vision is 12 m × 6 m. The illuminance thresholds of disability glare–interference glare (DGIG) and interference glare–acceptability glare (IGAG), along with the spatial distribution of each glare level, were collected at the longitudinal distances of 3 m, 5 m, 7 m, 10 m, and 12 m. Meanwhile, the illuminance threshold and the spatial distribution of each glare level up to a longitudinal distance of 120 m were calculated. The results indicate that disability glare is distributed in the central area, while interference glare and acceptability glare are distributed from the center to the margins. At the same longitudinal distance, the vertical illuminance of the driver’s eye under the same glare level is almost equal. In the range of a longitudinal distance of 120 m, the spatial distribution of each glare level enlarges with each increase in longitudinal distance. The results can provide scientific evidence for calculating the reasonable heights of anti-glare facilities for expressways with different alignments.

Contributed Session I: Impact of glare strength on Contrast Sensitivity

Clinical investigations of intraocular lenses are guided by ISO and ANSI standards, which outline parameters for procedures such as contrast sensitivity (CS). The effect of glare on CS is often studied, however is not standardized. ISO/ANSI recommend a level of glare that reduces mesopic CS by 0.1 log units at 6 cpd, determined through a small pilot study, however this ambiguous criterion might result in varying glare intensities across manufacturers. Healthy young adults (<40 yrs.), with VA of at least 20/20 were enrolled. Mesopic CS at 6 cpd was measured with and without glare in 39 subjects using the Clinical Trial Suite (CTS, M&S Technologies) and in 20 subjects using the CSV-1000 (Vector Vision) at 2.5 meters. Glare strength was set as standard for both devices (CTS:150 lux; CSV:12 lux, both before a 1.5 ND filter). Two attenuated glare levels (69 and 110 lux) were also evaluated with the CTS. The mean decrease in CS under standard glare strength was 0.16log units for CTS (95% CI 0.05, n=29) and 0.09log units (95% CI 0.08, n=12) for CSV. Under attenuated glare, the decrease in CS measured with the CTS was 0.14 (95% CI 0.06, n=20) and 0.15 (95% CI 0.05, n=24) log units for 69 and 110 lux, respectively, both above 0.1 log unit criteria. These results suggest that different criteria were used to calibrate glare strength of both systems, which resulted in ~12 fold difference in strength. Subsequently, clinical data obtained may not be comparable across these systems.

Clinical Outcomes of a New Hybrid Monofocal IOL With Extended Depth of Focus.

To evaluate a new extended depth of focus intraocular lens (IOL), the xact Mono-EDOF ME4 (Santen Pharmaceuticals), Conformitè Europëenne-marked as a monofocal IOL, which has four diffractive rings intended to enhance intermediate vision. Results are reported for 47 IOLs implanted in 28 patients who underwent cataract surgery and implantation of the xact Mono-EDOF ME4 IOL in one (9 patients) or both (19 patients) eyes. Postoperative follow-up examinations included visual acuity testing (monocular and binocular; uncorrected distance visual acuity [UDVA], corrected distance visual acuity [CDVA], uncorrected intermediate visual acuity [UIVA], distance-corrected intermediate visual acuity [DCIVA]), defocus curve and contrast sensitivity testing, and dysphotopsia evaluation. Follow-up at 6 months postoperatively revealed a monocular UDVA of 0.08 ± 0.15 logMAR, binocular UDVA of -0.02 ± 0.09 logMAR, monocular CDVA of -0.07 ± 0.08 logMAR, binocular CDVA of -0.09 ± 0.09 logMAR, monocular UIVA (70 cm) of 0.18 ± 0.16 logMAR, binocular UIVA (70 cm) of 0.09 ± 0.12 logMAR, monocular DCIVA (70 cm) of 0.25 ± 0.14 logMAR, and binocular DCIVA (70 cm) of 0.13 ± 0.11 logMAR. Defocus curve testing demonstrated a functional defocus of 1.25 diopters at 0.20 logMAR for monocular and 1.50 diopters at 0.20 logMAR for binocular testing. The contrast sensitivity corresponded to the age-appropriate normal values. Patients reported low levels of halo and glare. The xact Mono-EDOF ME4 IOL showed good functional results for far and intermediate distance visual acuity while inducing a low level of photic phenomena. [J Refract Surg. 2021;37(9):601-608.].

Evaluation of disability glare caused by headlights of most common vehicles in Iran

Background and Objectives: Road traffic accident is one of the leading causes of death in some countries such as Iran. Disability glare due to headlights of vehicles can increase the risk of crashes and make dangerous conditions. This study aimed to investigate the level of glare induced by the headlights of most common vehicles in Iran. Materials and Methods: This cross-sectional study was conducted in a suburban road of Ilam province in 2019. The disability glare resulted from the headlights of Pride Saba GTX, Pride 131SL, Samand Soren, Peugeot 405, Megan, and Peugeot Pars was measured at the distances of 10–100 m away from the headlights. The Threshold Elevation index under the high-beam and low-beam conditions (headlight's operation modes) was obtained for the background luminance condition including 1 and 50 cd/m2 for the age groups of 20, 35, 70, and 83 years old. Results: When the background luminance was 1 cd/m2, the mean glare level caused by the high-beam mode of illumination exceeded the recommended disability glare thresholds of all age groups. When the background luminance was 50 cd/m2, at certain longitudinal distances, glare level exceeded the disability glare thresholds of the elderly drivers (aged 70 and 83 years). At the background luminance of 1 cd/m2, low-beam mode of illumination caused disability glare at certain distances but not in general. At the background luminance of 50 cd/m2, low-beam mode of illumination did not cause disability glare at any distance. Conclusion: The results showed the mutual effect of luminance and the angle of line of sight with respect to glare source on the emergence of disability glare. The age also exhibited a significant association with the disability glare, as the highest glare levels were obtained for older drivers.

Comparison of visual outcomes after implantation of AtLisa tri 839 MP and Symfony intraocular lenses

PurposeTo compare visual outcomes after implantation of AtLisa tri 839 MP and Symfony intraocular lenses (IOLs).MethodsAll subjects underwent sequential bilateral cataract extraction with AtLisa tri 839 MP or Symfony IOL implantation. The design is prospective case series. Each group consists of 20 patients (40 eyes). At 1 year postoperatively, the following parameters were analysed: binocular uncorrected visual acuity (log MAR): for distance (UDVA) at 4 m, for intermediate distances (UIVA) at 60, 70, 80 cm and for near (UNVA) at 40 cm, defocus curve, mesopic and photopic contrast sensitivities (CSs), spectacle independence, visual function test questionnaire modified VFQ-25), photopic phenomena and postoperative complications.ResultsIn the AtLisa tri 839 MP group, the mean binocular UNVA and UIVA were significantly better than in the Symfony group (UNVA: − 0.01 ± 0.04 vs. 0.21 ± 0.15; p = 0.000; 60 cm UIVA: − 0.01 ± 0.04 vs. 0.09 ± 0.09, p = 0.001; 70 cm UIVA − 0.05 ± 0.06 vs. 0.11 ± 0.08, p = 0.002; 80 cm UIVA − 0.01 ± 0.06 vs. 0.15 ± 0.08, p = 0.019). There were no significant between-group differences in the mean binocular UDVA and CS, with one exception: the mean binocular distance CS (18 cpd) under mesopic conditions was significantly better in the Symfony group than in the AtLisa tri 839 MP group (1.39 ± 0.22 vs. 1.17 ± 0.27; p = 0.015). The defocus curve analysis revealed significant between-group differences at vergences of 2.0 to − 4.0 D (p < 0.05), except for 2.0, 1.0, 0 and − 1.5. All subjects in AtLisa tri 839 MP group and 18 subjects (90%) in Symfony group were spectacle independent. Patients from both groups highly rated their overall vision quality in the VFQ-25 (1.67 ± 0.47 vs. 1.85 ± 0.5 in the Symfony and AtLisa tri 839 MP group, respectively, p = NS). The scores for daytime driving (1.00 ± 0.00 vs. 1.21 ± 0.36; p = 0.002), night driving (1.57 ± 0.55 vs. 2.13 ± 1.15; p = 0.027) and difficult situation driving (1.14 ± 0.31 vs. 1.53 ± 0.56; p = 0.049) were significantly better in the AtLisa tri 839 MP group than in the Symfony group. The incidence and perception level of halo and glare were significantly reduced (p = 0.00) in the Symfony group as compared to the AtLisa tri 839 MP group. The postoperative course was uneventful in all subjects.ConclusionsVisual outcomes achieved with both IOLs are comparable. In both groups, 90% of patients achieved spectacle independence. Whereas the AtLisa tri 839 MP IOL implantation was associated with slightly better intermediate distance VA and significantly better near VA, photic phenomena were less perceived by patients with Symfony IOLs.