Effects of glare on binocular vision and reading behaviour performing computer work

We spend more and more time working with computers. When we do so our central visual field lacks three-dimensional (3D) features and this leads to reduced binocular control and may result in eye-related symptoms. When other factors such as direct and indirect glare are added to a computer work situation further stress is placed on the visual system and binocular control may be even further reduced and our reading behaviour may also be influenced. These factors are likely to contribute to the vision- and eye symptoms referred to collectively as computer vision syndrome (CVS). Three areas of clinical study are included in the context of using a computer screen for demanding near visual tasks. This research aimed to explore the theoretical relationship between: (1) the importance of centrally placed 3D features in respect to accommodation and vergence mechanisms; (2) the influence of degraded stimuli and/or degraded retinal image on the quality of binocular vision as an indicator of visual fatigue; (3) the influence of degraded stimuli and/or degraded retinal image on eye movements when reading. Paper I clarified the importance of implementing centrally placed 3D fixation stimuli to contribute to increase vergence accuracy and fixation stability. Paper II evaluated the influence of disability glare on binocular coordination. The results indicated that binocular coordination increased in instability with the severity of glare and there was a more pronounced effect when lighting condition created direct glare. Paper III described the influence of disability glare on eye movements when reading. It is clear that these eye movements were negatively affected in the direct- and indirect glare lighting conditions. Paper IV evaluated the threshold luminance of direct glare using a subjective response regarding eye symptoms in addition to an evaluation of the effect on binocular coordination as a benchmark. Direct glare of 2000 cd/m2 was found to decrease the instability of binocular coordination with an increased level of eye pain. In conclusion, these findings argue for a more pronounced relationship between reduced cues of centrally placed 3D features when working with computers with elevated exposure to disability glare. Direct glare appears to degrade the visibility of the retinal image to such a high degree that it can be identified as the most pronounced inappropriate lighting condition. Evaluation of the luminance threshold of direct glare suggests that it reasonable to recommend that stray light toward the eyes should be significantly lower than 2000 cd/m2. This research has taken a step in the direction of justifying the importance of following lighting design recommendations in computer work environments

Multi-method approach for evaluating visual conditions incontrol room environments

With increased automation and implementation of information and communicationtechnology in occupational settings, more people are working in control room environments across various sectors. The work often involves continuous visual assessments of several screens. Poor visual conditions can cause eye-related problems and musculoskeletal disorders.The purpose of this paper is to describe and discuss the rationale for, and the procedures of, a methodological approach for evaluating visual conditions in control room environments. The paper draws from experiences gained at four field studies in Sweden, where 13 different control rooms have been assessed and involving 30 control room operators. The multi-methodapproach produces a comprehensive and contextualized understanding of the visual requirements, as well as of the operators’ perceived work load, visual experience and eyerelatedhealth. The experiences support the relevance of providing an optimized visual environment when designing control room work for a safe, sustainable and inclusive working life

Visual fatigue during control room work in process industries

BACKGROUND: Working in front of computer screens is visually demanding and related to adverse eye symptoms. Occurrence of glare further increases visual fatigue. OBJECTIVE: This paper presents results from an examination of visual ergonomics in control room environments at two Swedish process industries. METHODS: Visual conditions were examined and evaluated in nine control rooms and eighteen process operators answered questions about their perceived workload and visual experiences. RESULTS: When working in the control rooms, the mental workload was rated significantly higher by the participants, compared to experienced performance. The operators further experienced significantly higher visual fatigue and blurred vision compared to double vision and sore eyes. Visual demands were increased in conditions where contrast glare was present, as well as frequent changes of focusing distances, and low contrast between background and characters in computer screens. CONCLUSIONS: Suboptimal visual working conditions in the control rooms contributes to increased visual demands on the operators. Presence of glare is leading to visual fatigue and an unnecessary high mental load. The findings support the relevance of considering principles of general and visual ergonomics when designing and organizing work in control rooms. Workstation design should also be flexible to allow for individual and contextual adjustments

Risks in the visual environment such as glare, illuminance, and luminance ratio - risk assessments made with visual ergonomics risk assessment method - VERAM - a descriptive paper

The visual environment has an impact on subjective strain and headaches. A visual ergonomics risk assessment method, VERAM, was used on 217 workplaces, and consists of both of a subjective questionnaire and an objective risk assessment, the objective risks are presented in this paper. The risk for daylight was assessed to be yellow (risk) or red (high risk) at 53% of the workplaces and the risk for glare was yellow or red at 66%. The assessment of the lighting design showed a yellow or red risk at 44% of the workplaces and the illuminance was assessed to be insufficient at 49% of the workplaces. Flicker or TLM (temporal light modulation) was assessed to be a problem among 33%. These results show that the design of the visual environment is in most cases not performed in a satisfying way. To increase wellbeing, health and performance a good visual environment is essential

Belysning och utveckling av undersökningsrum : Multifunktionsrum i sjukvården

Employees in an eye hospital spend many hours in semidarkness or darkness performing visually demanding activities that can cause fatigue and eye strain. As preparation for the planning of a new eye hospital, this project was initiated in order to produce knowledge of how to improve lighting in examination rooms. Current light conditions at S:t Erik Eye Hospital were assessed including questionnaires to employees/patients, and measurements of luminance, space analyses and energy consumption. Visits to other prominent eye hospitals and a literature review were performed. The questionnaires revealed that eyestrain problems were common in eye care professionals, especially in women. Working in dark rooms increased the subjective feeling of fatigue. Many, but not all, lacked daylight. The general lighting system was often insufficient with poor light distribution, shadows, and a colour temperature that in general was too low. Improvements included possibilities to regulate inflow of daylight, installation of remote controls, and timing and level of adaptation to different light levels. These improvements have been tested in a real scale installation that used the latest technology in terms of artificial lighting, a lighting control systems and a novel solution to control daylight. Five different light scenarios were preinstalled and evaluated by professionals and patients. A majority reported an improvement compared with traditional solutions. Current and actual energy consumption was monitored. Simulations of future consumption points to a possible energy reduction by 50 %, using new lighting technology, daylight and optimal room design. With improved logistics, new buildings and new work organization, energy savings can be even higher, around 70 %.QC 20130611</p

Strategies to develop and strengthen human factors and ergonomics knowledge among stakeholders in Sweden

Knowledge and application of human factors and ergonomics (HFE) has significant potential as auseful tool and solution provider in the development, design and implementation of safe, efficient and sustainable artefacts and systems. Yet, it seems that this HFE knowledge is not utilised to its full potential. In a world of competing financial and commercial priorities, HFE specialists have apparently not succeeded in selling the systems approach as a tool towards improved overall systems performance and human well-being. The present paper describes the strategic and practical workperformed by the Swedish Ergonomics and Human Factors Society (EHSS) to strengthen the quality of human factors and ergonomics knowledge and practice among various stakeholders in Sweden. EHSS view human factors and ergonomics as a systems and design oriented discipline that extends across all aspects of human activity. Beyond the traditional domains of specialization within the discipline, the physical, cognitive and organisational ergonomics, EHSS has identified three focus areas; visual ergonomics, voice ergonomics and ergonomics design for all. Practitioner Summary: This paper presents the strategic and practical work performed by the Swedish Ergonomics and Human Factors Society (EHSS) in order to strengthen the quality of human factors and ergonomics knowledge and practice in Sweden. EHSS has identified three focus areas for its strategic work: visual ergonomics, voice ergonomics and ergonomics design for all

Strategies to develop and strengthen human factors and ergonomics knowledge among stakeholders in Sweden

Knowledge and application of human factors and ergonomics (HFE) has significant potential as auseful tool and solution provider in the development, design and implementation of safe, efficient and sustainable artefacts and systems. Yet, it seems that this HFE knowledge is not utilised to its full potential. In a world of competing financial and commercial priorities, HFE specialists have apparently not succeeded in selling the systems approach as a tool towards improved overall systems performance and human well-being. The present paper describes the strategic and practical workperformed by the Swedish Ergonomics and Human Factors Society (EHSS) to strengthen the quality of human factors and ergonomics knowledge and practice among various stakeholders in Sweden. EHSS view human factors and ergonomics as a systems and design oriented discipline that extends across all aspects of human activity. Beyond the traditional domains of specialization within the discipline, the physical, cognitive and organisational ergonomics, EHSS has identified three focus areas; visual ergonomics, voice ergonomics and ergonomics design for all. Practitioner Summary: This paper presents the strategic and practical work performed by the Swedish Ergonomics and Human Factors Society (EHSS) in order to strengthen the quality of human factors and ergonomics knowledge and practice in Sweden. EHSS has identified three focus areas for its strategic work: visual ergonomics, voice ergonomics and ergonomics design for all

Conceptual and Practical Strategy Work to Promote Ergonomics/Human Factors in Sweden

This paper describes the results of the conceptual and practical strategy work performed by the Swedish Ergonomics and Human Factors Society (EHSS) today. The rationale of EHSS is to strengthen the quality of ergonomics/human factors knowledge and practice in Sweden and form a multidisciplinary platform across disciplines and professions for collaboration and for knowledge sharing. EHSS gathers about 350 members, representing different occupations in industry, academia and the public sector. Together, EHSS members hold knowledge and experience in physical, cognitive and organizational ergonomics and its application in working life and society. The overall aim of this paper is to inspire related societies and stakeholders to initiate discussions about strategies and future projects that allow for collaboration and knowledge sharing. Proposedly follow the EHSS model where we have formed a multidisciplinary platform for collaboration across disciplines and professions. The activities initiated and supported by EHSS are one step towards broadening the knowledge and application of HFE in Sweden, and to comprise new arenas of specialization. By participating in the key areas in society such as teaching, standardization, product development and occupational safety and health, the work of EHSS is one piece of the puzzle to improve human activities in the future. The vision is that together, we can improve safety, efficiency and well-being for all