The Visual Preference, Aesthetic Judgement, and Mood Response to Human-Centric Lighting in Office Spaces

Architectural lighting is a significant visual stimulus that impacts the occupants' moods and aesthetic experiences within the office environment. Previous literature suggests that the good quality of architectural lighting is considered an important factor that contributes to the visual aesthetic experience of an environment through psychological mechanisms. Lighting uniformity, luminance distribution, and direct/indirect lighting have been discussed in other studies, but lighting spatial patterns are unclear. In particular, assessing the combined effects of lighting parameters on human mood and visual aesthetic experience is challenging. Featured film scenes depicting office environments offer convenient material to study the effects of Lighting on occupants' visual perception and mood.This thesis presents the result of an exploratory mixed-method approach to determine how human-centered lighting design affects occupants' mood, visual aesthetic judgment, and visual preferences in open office spaces. Six spatial lighting patterns of open office workstations were analyzed using image content analysis of selected film scenes. The six rendered images were presented to 60 participants via an online survey to determine their preferences, interests, and aesthetic judgments. This research has revealed that two light spatial patterns were significantly preferred among the six lighting spatial patterns. The first lighting spatial pattern (LS-3) that the overall low average luminance environment, equipped with work view region lighting, which also has a higher luminance ratio (R), is visually preferred. In terms of the higher overall average luminance environment (LS-4), people preferred the overall uniform luminance without desk area lighting with a low luminance value (R). The study also indicated that subjects’ aesthetic judgment (mood repones) and the lighting spatial patterns (LS- 3) within lower overall average illuminance and only equipped with diffused pendant lighting and desk area lighting triggered visually felt more pleasant, relaxed, and satisfied

TFOS lifestyle: Impact of the digital environment on the ocular surface

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as “the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing”. Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not ‘diagnostic’ of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts)

Daylighting design for energy saving in a building global energy simulation context

A key factor to substantially reduce the energy consumption for electric lighting consists in a more widespread exploitation of daylight, associated with the use of the most energy efficient lighting technologies, including LEDs or electric lighting controls. At the same time daylight harvesting in indoor spaces can influence the global energy performance of a building also in terms of heating and cooling loads. For this reason, it’s always necessary to account for the balance between daylighting benefits and energy requirements. Furthermore the increasing awareness of the potential benefits of daylight has resulted in an increased need for objective information and data on the impact that different design solutions, in terms of architectural features, can have on the daylighting condition and energy demand of a space. Within this frame the research activity has been focusing on three main aspects: − Analyzing limits and potentials of the current daylighting design practice and proposing synthetic information and tools to be used by the design team during the earliest design stage to predict the daylight condition within a space. − Analyzing the effect of a proper daylighting design approach on energy requirements for electric lighting, associating with the use of efficient lighting technologies and control systems. − Assessing the influence of energy demand for electric lighting on the global energy performance. The methodology that was adopted relies on dynamic simulations carried out with Daysim and EnergyPlus used in synergy to perform a parametric study to assess the indoor daylighting conditions and the energy performance of rooms with different architectural features. Within the first phase the database of results of the lighting analysis was used to assess the sensitivity of new metrics which have been proposed by the scientific community as predictors of the dynamic variation of daylight. Furthermore it was analyzed how indoor daylight can be influenced by room’s architectural features. Than the energy demand for electric lighting for all simulated case studies have been analyzed so as to examine the influence of a proper daylighting design in presence of different lighting control systems. Finally results related to the amount of daylight available in a space were compared with annual energy demand for lighting, heating and cooling to highlight the influence of a proper daylighting design on the global energy performance

How visual ergonomics interventions influence health and performance - with an emphasis on non-computer work tasks

Visual ergonomics evaluations and interventions were performed on non-computer work tasks at recycling facilities, post sorting facilities and operating theatres. The results can to some extent be applicable to other professions and workplaces. The purpose of the research was to investigate the effects of visual ergonomics interventions on eyestrain, musculoskeletal discomfort, headache, and visual performance at work. Individuals with eyestrain reported more musculoskeletal discomfort than individuals without eyestrain. Factors shown to have an impact on eyestrain and musculoskeletal discomfort were the visual environment, the individual’s perceived visual ability and need for spectacles. Such findings have been reported among computer users. The results presented here show that non-computer work tasks may induce similar findings as well. Evaluations of workplaces and interventions with lighting and spectacles were performed in the studies presented in this thesis. The interventions were evaluated by direct observations such as an expert approach and by indirect observations by means of questionnaires. After the evaluation and measurement of the lighting at the recycling facilities, a number of lighting recommendations were suggested to increase visibility and reduce accident risks. For the younger postal workers in particular, better lighting reduced eyestrain and musculoskeletal discomfort. Pre-intervention, the individuals with eyestrain had lower productivity than those without; their productivity increased with better lighting. The musculoskeletal discomfort from the neck decreased especially from the static side for the postal workers after they were provided with correct power in their spectacles. It is possible to improve the work posture of presbyopic postal workers with customised sorting spectacles, in particular because using the sorting spectacles results in a decrease of the backward tilt of the head. In visually demanding work such as surgery, the luminance contrast within the visual field is essential. This is especially the case for the scrub nurse who has to look into the very bright operating light and also see the less highly lit instrument table and other important aspects in the operating room. The visual focus of the surgeons is in the operating cavity, and their eyes are completely adjusted to that level. It can take up to two minutes before their vision is fully functioning again after being exposed to the high illuminance from the operating cavity. This poses a risk if something happens in the operating room outside the operating cavity that requires good visibility from the surgeon. It is thus vital to increase the general lighting in an operating room, especially around the operating table, to decrease the luminance contrasts and facilitate the operating personnel’s visual ability. In this intervention study, the operating personnel rated the improved lighting as improving their perceived visual ability and a decreasing tiredness. All together, the studies show that visual ergonomics is a multidisciplinary science that requires a holistic approach. This thesis will hopefully contribute to increasing the awareness of the effects of a good visual environment and its benefits for the individual’s health