Tor Martin Kvikstad

Eye-related pain induced by visually demanding computer work.

Purpose. Eye strain during visually demanding computer work may include glare and increased squinting. The latter may be related to elevated tension in the orbicularis oculi muscle and development of muscle pain. The aim of the study was to investigate the development of discomfort symptoms in relation to muscle activity and muscle blood flow in the orbicularis oculi muscle during computer work with visual strain. Methods. A group of healthy young adults with normal vision was randomly selected. Eye-related symptoms were recorded during a 2-h working session on a laptop. The participants were exposed to visual stressors such as glare and small font. Muscle load and blood flow were measured by electromyography and photoplethysmography, respectively. Results. During 2 h of visually demanding computer work, there was a significant increase in the following symptoms: eye-related pain and tiredness, blurred vision, itchiness, gritty eyes, photophobia, dry eyes, and tearing eyes. Muscle load in orbicularis oculi was significantly increased above baseline and stable at 1 to 1.5% maximal voluntary contraction during the working sessions. Orbicularis oculi muscle blood flow increased significantly during the first part of the working sessions before returning to baseline. There were significant positive correlations between eye-related tiredness and orbicularis oculi muscle load and eye-related pain and muscle blood flow. Subjects who developed eye-related pain showed elevated orbicularis oculi muscle blood flow during computer work, but no differences in muscle load, compared with subjects with minimal pain symptoms. Conclusions. Eyestrain during visually demanding computer work is related to the orbicularis oculi muscle. Muscle pain development during demanding, low-force exercise is associated with increased muscle blood flow, possible secondary to different muscle activity pattern, and/or increased mental stress level in subjects experiencing pain compared with subjects with minimal pain.

Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape

This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed. The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view.

Will Musculoskeletal, Visual and Psychosocial Stress Change for Visual Display Unit (VDU) Operators When Moving From a Single-Occupancy Office to an Office Landscape?

This study investigated the effect of moving from single-occupancy offices to a landscape environment. Thirty-two visual display unit (VDU) operators reported no significant change in visual discomfort. Lighting conditions and glare reported subjectively showed no significant correlation with visual discomfort. Experience of pain was found to reduce subjectively rated work capacity during VDU tasks. The correlation between visual discomfort and reduced work capacity for single-occupancy offices was rs = .88 (p = .000) and for office landscape rs = .82 (p = .000). Eye blink rate during habitual VDU work was recorded for 12 operators randomly selected from the 32 participants in the office landscape. A marked drop in eye blink rate during VDU work was found compared to eye blink rate during easy conversation. There were no significant changes in pain intensity in the neck, shoulder, forearm, wrist/hand, back or headache (.24 < p < .67). Pain levels in different body areas were significantly correlated with reduced work capacity, .77 < rs < .99 (p = .000).

The impact of second home tourism on local economic development in rural areas in Norway

Over recent decades, rural–urban migration and a decrease in wealth have been major challenges faced by European rural areas. Maintaining urban and rural settlements throughout the country has been an important aim of Norwegian regional politics. This paper assesses the impact of second home tourism on local economic development in rural municipalities in Norway. The study is based on data collected as part of an ongoing research project initiated in 2002. Having developed and tested a model consisting of socio-economic factors and factors associated with the second home as such, the authors examine how and to what extent these factors explain the impact of second home tourism on local economic growth. They find that the size and standard of the recreational home are important factors in explaining variations in annual consumption by second home owners, and more so in rural communities with a broad and well-structured trading activity than in areas with a weaker trading structure. It appears that urban recreational tourism based on second homes of high standard offers the best potential for sustainable local rural economic growth. Based on their findings, the authors also discuss possible local government strategies to achieve economic growth through second home tourism.

Happy Living in Darkness! Indoor Lighting in Relation to Activities of Daily Living, Visual and General Health in 75-Year-Olds Living at Home

ABSTRACT Lighting has been identified as a significant environmental attribute for promoting vision and general health among older people, enabling successful aging at home, but it has received little attention in the literature. Indoor lighting levels, self-reported vision and general health, and activities of daily life were measured in 114 healthy 75-year-old Norwegians. Despite very low levels of indoor lighting, the subjects were happy and healthy. There is a large discrepancy between self-assessed health and recommended lighting levels, and low awareness of the effect of lighting on age-related vision loss or daily living in the future. Knowledge of how to utilize indoor lighting to ensure healthy and safe aging in the home is needed.

Reliability of muscle blood flow measurements in orbicularis oculi.

Purpose Orbicularis oculi muscle tension and muscle blood flow have been shown to be objective measures of eyestrain during visually demanding activities, such as computer work. In line with this, positive associations between eye-related pain and muscle blood flow in orbicularis oculi have been observed. A hypothesis regarding work situations with cognitive tasks and low-level muscle activity, such as computer work, proposes that muscle pain originates from the blood vessel-nociceptor interactions of the connective tissue of the muscle. Noninvasive muscle blood flow measurements in the orbicularis oculi muscle are preferable to using an invasive technique. The aim of this study was to test reproducibility and stability of muscle blood recordings in orbicularis oculi using photoplethysmography. Methods In the reproducibility tests, 12 subjects were tested twice within 1 to 5 weeks. To study the stability of the method, six of the subjects were randomly selected and tested four more times within 2 to 6 weeks. Test subjects were doing identical visually demanding computer work for 10 minutes in each test. Results The short-term repeatability of muscle blood flow measurements was considered good, but the stability of blood flow recordings over time in orbicularis oculi was low because of a greater within-subject maximum variability compared with between-subject average variability. Conclusions Investigators should be aware of the effect of time, possibly attributed to confounding factors such as environmental changes and mental stress, when comparing photoplethysmography muscle blood flow recordings.

Do the luminance levels of the surroundings of visual display units (VDU) and the size of the characters on the screen effect the accommodation, the muscle load and productivity during VDU work?

This study aims at quantifying how much a background glare situation of a VDU, and different text sizes influence muscle load and production. Production was evaluated both as quantity of work, and number of errors that were made. The results showed no significant changes in the postural load in terms of electromyographic (EMG) measurements of m. trapezius and m. infraspinatus. However, a significant decrease in working speed and productivity was seen. There were no significant changes in the number of errors that was done. The transient myopic shifts (TMS) observed in an earlier study among presbyopic users [1] were not as clear in this study.