Visual Comfort for Motorists

Existing visual comfort metrics are reviewed and critiqued based upon their ability to explain the variability in human subjective responses in a daylit private office laboratory environment. Participants (n = 48) evaluated visual comfort and preference factors, totaling 1488 discreet appraisals, and luminance-based metrics were captured with high dynamic range images and illuminance-based metrics were recorded. Vertical illuminance outperformed all commonly referenced visual comfort metrics including horizontal illuminance, IES luminance ratios, daylight glare probability (DGP), and daylight glare index (DGI). The bounded borderline between comfort and discomfort is introduced, and preliminary visual comfort design criteria are proposed for several existing metrics. Fundamental limitations of glare indices are documented, and the implications of inconsistent application of luminance ratio calculation methods are quantified. Future research is detailed.

The visual feeling of a luminous environment in indoor stadiums is essential to athletes and spectators. Creating a visually comfortable luminous environment in indoor stadiums that rely solely on artificial lighting is necessary. Current visual comfort metrics based on luminance require designers to keep luminance or luminance ratios within certain ranges, which makes it challenging to satisfy these requirements for visual comfort at the design stage due to the difficulty of measuring luminance. The multiple lighting standards and power demand enhance the complexity of lighting design for indoor stadiums. Aiming at these, this article first takes the RAVI (ratio of the average vertical illuminance) of the spectator stands relative to the playing field for indoor stadiums. It was found that visual comfort is optimal when RAVI reaches 0.4 through a VR (virtual reality) subjective evaluation experiment. Subsequently, the optimal RAVI is implemented in a multi-objective optimization method, NSGA-II (Non-dominated Sorting Genetic Algorithm-II), as a constraint is applied for lighting optimization design to optimize the lighting standards and power demand taking the example of the basketball field. The results show that the optimized solution satisfies the proposed RAVI while meeting the lighting standards (Chinese standard JGJ 153–2016) and having relatively low energy consumption. The energy efficiency of this method is verified, and the results show that the uniformity of illuminance is increased by at least 7%, and the total power of the luminaires is reduced by 13%. This study provides a reference for lighting optimization design considering visual comfort in indoor stadiums.

Assessment and optimization of tunnel lighting quality based on drivers' visual comfort: From methodology to application

The EBD-SIM (evidence-based design, simulation) framework is a conceptual framework developed to integrate the use of lighting simulation in the EBD process to provide a holistic performance evaluation method. A real-time case study, executed in a fully operational office building, is used to demonstrate the framework’s performance. The case study focused on visual comfort analysis. The objective is to demonstrate the applicability of the developed EBD-SIM framework using correlations between current visual comfort metrics and actual human perception as evaluation criteria. The data were collected via simulation for visual comfort analysis and via questionnaires for instantaneous and annual visual comfort perception. The study showed that for user perception, the most crucial factor for visual comfort is the amount of light on a task area, and simple metrics such as Eh-room and Eh-task had a higher correlation with perceived visual comfort than complex performance metrics such as Daylight Autonomy (DA). To improve the design process, the study suggests that, among other things, post-occupancy evaluations (POEs) should be conducted more frequently to obtain better insight into user perception of daylight and subsequently use new evidence to further improve the design of the EBD-SIM model.

BackgroundCeramic tiles are widely used in workplace environments, and their visual characteristics can influence users’ perceptual and cognitive experiences. However, research remains limited on how ceramic tile properties affect visual comfort, cognitive performance, and related neural responses.MethodThis study examines six common types of mass-produced ceramic tiles, employing virtual reality (VR) and electroencephalogram (EEG) technologies to evaluate visual comfort and cognitive performance. A 2 (patterned vs. non-patterned) × 3 (light-toned, medium-toned, dark-toned) factorial design was used to construct six immersive VR environments through 3D modeling. Data on visual comfort ratings, cognitive behavioral performance, and EEG responses were collected from participants in each environment. The effects of tile’s pattern and brightness on visual comfort, cognitive outcomes, and neural activity were analyzed.ResultThe findings indicate that environments with non-patterned and light-toned ceramic tiles received higher visual comfort ratings and elicited increased alpha wave power spectral density, reflecting positive emotional experiences. In terms of cognitive performance, the participants had shorter reaction durations in the environments of light-toned ceramic tiles and patterned ceramic tiles, and were negatively correlated with the beta wave power spectral density values.DiscussionThe results suggest that ceramic tile selection can be tailored to the functional needs of interior spaces. For instance, in relaxing settings such as lounges, tiles that enhance alpha-wave activity may be preferable, while in workspaces requiring high cognitive engagement--such as studios, meeting rooms, or offices--tiles that promote moderate beta-wave activity may be more suitable. This study provides valuable insights and evaluation methods for interior and ceramic tile designers, especially for design of Chinese region.

Guest Editorial: Shedding new light on the twilight zone

Color asymmetry of the left and right views is a common phenomenon in the stereoscopic three‐dimensional (S3D) display, which can lead to visual discomfort. Due to visual discomfort is a subjective sensation, we hypothesize that variations of pupil diameter while viewing S3D images are related to experienced visual comfort. To test this hypothesis, we conducted eye‐tracking experiments on humans viewing hue‐asymmetric stereoscopic images while simultaneously collecting their judgment scores of experienced visual discomfort. From the collected eye‐tracking data, pupil diameter variations were extracted by a normalization formula. Results show that change in hue asymmetry levels causes a significant change in pupil diameter variations. There was a strong negative correlation between the pupil diameter variation and the visual comfort assessment (VCA) score, and the Pearson's r = −0.8936. We conclude that as the hue asymmetric level of stereoscopic image increases, the pupil diameter of the participant becomes smaller and the visual comfort decreases. A visual comfort predication model was fitted well using pupil diameter variation. It predicts that when the pupil diameter variation exceeds 20.57%, the brain feels visual discomfort.

Visual comfort models based on coloured text and neutral background combinations

Effects of non-uniform perforated solar screen on daylighting and visual comfort performance

Daylighting is essential to the well-being of occupants in educational spaces. It increases students’ performance and provides an opportunity for achieving energy efficiency, as well as indoor visual and thermal comfort. However, daylight performance is rarely accounted for when taking decisions attributed to building renovation. This results in increased or decreased daylighting lighting levels and glare which jeopardizes the functional requirements of the space. Hence, this study adopted a mixed qualitative/quantitative approach to compare two recently renovated educational spaces (architectural design studio drawing halls) in terms of the effect of renovation activities on daylighting and visual comfort, noting that both spaces were located in the same building and subject to similar prevailing climatic conditions. This included a sequence of site measurements, surveys and simulations. The results showed great variation between both studied spaces in terms of daylight efficiency and visual comfort. Some design proposals were tested in order to deduct learnt lessons for proper accounting of daylight during building renovation plans.

Comparison of novel digital microscope using integrated intraoperative OCT with Ngenuity 3D visualization system in phacoemulsification

Adequate daylighting is a vital element of effective learning environments, profoundly affecting students' visual comfort, cognitive performance, and psychological well-being. Insufficient access to natural light not only hampers academic productivity but can also negatively impact the physical and mental health of occupants. In tropical climates such as Chittagong, Bangladesh, the design of educational buildings must strike a careful balance between daylight access and thermal comfort. While external shading devices play a crucial role in minimizing solar heat gain and glare, they can also obstruct daylight entry, potentially diminishing indoor lighting quality. This study explores how different configurations of external shading devices influence daylight performance in south-facing classrooms, using a typical classroom at the Chittagong University of Engineering and Technology (CUET) as a case study. A mixed-method approach was adopted, integrating on-site illuminance measurements with daylight simulation tools to evaluate the effectiveness of the existing shading strategies. Alternative shading configurations were subsequently proposed and analyzed to assess their impact on indoor daylight distribution. The findings indicate that carefully optimized shading geometries can enhance daylight penetration while maintaining acceptable thermal comfort levels, thus improving overall indoor environmental quality. This research provides evidence-based design recommendations for the integration of passive shading solutions in classroom architecture, aiming to assist architects and designers in creating sustainable, energy-efficient educational environments that support both visual comfort and occupant well-being in tropical regions.

Daylighting is an effective method in creating a comfortable visual environment and energy efficiency in university buildings. The potential for energy savings through daylighting studies is great was investigated using a case study approach on the three design studios in KAED Building, International Islamic University Malaysia (IIUM). The methodology simultaneously undertook field measurements and opinion surveys in the studios facing north, south, and northwest. Daylighting measurements using the Lux-Meter and calculations of the lighting energy consumption were conducted. The questionnaire survey was distributed to the users of the studios to assess their opinions on visual comfort. The results showed that the lighting levels were not up to the required standard. However, the lack of daylight did not hinder the users' visual comfort. The study proposed changing the existing less-efficient Fluorescent-T8 lamps to the more-efficient LED (light-emitting diode) lights for energy efficiency. Calculations on the annual energy consumption yielded a 40% reduction in the lighting bills and a payback period of around five years.

Lighting plays an important role in the Hospital Diagnostic and Treatment Room. It shall be environmentally and functionally suitable for three groups of people: patients, hospital professionals and visitors. On the other hand lighting is considered a major consumer of electrical energy and therefore, hospital lighting design should consider the visual performance, visual comfort and energy efficiency. This article discusses the performance of different types of lighting installations used for hospital lighting system design applications: first the visual comfort and second to save energy consumptions in such applications. DIALux 4.8 simulation software is used to study and evaluate the efficient lighting scheme for the hospitals through the use of different types of lamps. Also, visual environment lighting system design procedure is explained. Economics of different lighting scenarios are highlighted.

This paper proposes a new disparity remapping framework to improve the visual comfort of stereoscopic images. The proposed framework adaptively remaps disparities of a scene according to different causes of visual discomfort. A linear disparity remapping is first performed in order to address visual discomfort induced by excessive disparities. This linear remapping changes the disparities of the scene to obtain an overall target disparity range. Then, a nonlinear disparity remapping process selectively adjusts the disparity of problematic local disparity ranges according to their contribution to the visual discomfort. The proposed nonlinear disparity remapping process enables us to minimize the loss in perceived depth range while further improving visual comfort. The effectiveness of the proposed disparity remapping framework has been successfully evaluated by subjective assessments of visual comfort and naturalness. Experimental results demonstrate the validity of the proposed remapping framework. More importantly, we show that the nonlinear refinement of disparity in problematic regions can efficiently improve visual comfort while maintaining the naturalness of the scene.