Magne Helland

Demographics of international contact lens prescribing

Knowledge of differences in the demographics of contact lens prescribing between nations, and changes over time, can assist (a) the contact lens industry in developing and promoting various product types in different world regions, and (b) practitioners in understanding their prescribing habits in an international context. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA between 2000 and 2008 reveal an ageing demographic, with Japan being the most youthful. The majority of fits are to females, with statistically significant differences between nations, ranging from 62 per cent of fits in Norway to 68 per cent in Japan. The small overall decline in the proportion of new fits, and commensurate increase in refits, over the survey period may indicate a growing rate of conversion of lens wearers to more advanced lens types, such as silicone hydrogels.

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.

International rigid contact lens prescribing.

Rigid lenses have been fitted less since the introduction of soft lenses nearly 40 years ago. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA between 2000 and 2008 facilitate an accurate characterization of the pattern of the decline of rigid lens fitting during the first decade of this century. There is a trend for rigid lenses to be utilized primarily for refitting those patients who are already successful rigid lens wearers-most typically older females being refit with higher Dk materials. Rigid lenses are generally fitted on a full-time basis (four or more days of wear per week) without a planned replacement schedule. Orthokeratology is especially popular in the Netherlands, but is seldom prescribed in the other countries surveyed.

A multidisciplinary approach to solving computer related vision problems

Citation information: Long J & Helland M. A multidisciplinary approach to solving computer related vision problems. Ophthalmic Physiol Opt 2012, 32, 429–435. doi: 10.1111/j.1475‐1313.2012.00911.x

Soft toric contact lens prescribing in different countries.

There have been significant improvements in toric soft contact lens design over the past decade. Data from our international contact lens prescribing survey were mined to assess recent trends in toric soft contact lens fitting. This survey was conducted by sending up to 1000 survey forms to contact lens fitters in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA each year between 2000 and 2009. Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the forms and to return them to us for analysis. The data revealed a gradual increase in the extent of toric soft lens fitting this century. Excluding Japan--which had a consistently low rate of soft toric lens fitting over the survey period--soft toric lenses now represent over 35% of all soft lenses prescribed; it can be assumed that, on average (and again excluding Japan), all cases of astigmatism 0.75 D or less remains uncorrected among contact lens wearers. Toric lenses are fitted more to those who are older, full-time wearers and reusable lens wearers, and less to those wearing silicone hydrogel and extended wear lenses.

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.

The influence of staff use of a virtual learning environment on student satisfaction

The use of virtual learning environments in higher education has shown significant growth over the last few years. This presents challenges in a variety of ways, challenges to provide effective educational materials within virtual learning environments (VLE), challenges in teaching style and the development of appropriate pedagogy. In this paper we discuss the work done introducing a VLE at Buskerud University College (HiBu) in Norway, and the impact that there can be shown through the use of satisfaction surveys, A longitudinal survey which have been carried out on general level of student satisfaction over a nine year period, a specific survey on satisfaction with the use of a VLE and a survey on staff attitude to e-learning. Our interest is in considering how the introduction of the VLE itself has impacted on satisfaction of students, whether it has changes the nature of the environment and whether it has resulted in changes in expectations. And from the survey we will attempt to describe what effects it has had HiBu has been engaged in a number of activities aimed at increasing staff and student use of its VLE. These efforts have been focused on training staff in different discipline areas and some training of students, and the optimisation of the development of learning material to support academic activity. Additionally there has been further product training in the various facilities available through the VLE to support other aspects of academic factors. This training has not been limited to the lecturing staff but includes all categories of employees. Additionally HiBu has established a major task in focusing on the pedagogical model to support the use of the VLE. This task has been the responsibility of a group of predominantly academic staff, but with representation from technical and library staff. The responsibility of this group has been to identify this pedagogical model as the basis for e-learning within HiBu. HiBu has been collecting data on student satisfaction for a number of years, both pre and post use of the VLE. The model adopted for the student satisfaction surveys is reasonably consistent, with the exception of some questions that have been introduced to cover the use of the VLE. As a result of this HiBu has been able to determine the effect on student satisfaction of the use of the VLE. There has been no significant change in the satisfaction levels in the last few years. However there is a notable change in the student requests for change of activities.

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.

Can visual discomfort influence on muscle pain and muscle load for visual display unit (VDU) workers

In three different prospective epidemiological studies, correlation between visual discomfort and average pain intensity in the neck and shoulder, were 0.30<r<0.72 for VDU workers. In the first study, correlation between visual discomfort and pain in the neck and shoulder was 0.30<r<0.40. In the second study, visual discomfort was related to neck pain, (r=0.40, p=0.003). In the third study, visual discomfort correlated to neck pain (r=0.69, p=0.000) and shoulder pain (r=0.72, p=0.000). In order to study more in detail the correlation between visual stress and muscle load, a laboratory study was carried out. Visual stress was induced by the size of characters on the screen (8 points and 12 points Times New Roman) and the luminance levels in the surroundings of the screen (between 1500 and 2300 cd/m2) versus (between70 and 100 cd/m2). The results showed that the smallest characters 8 points and the highest luminance levels had no significant influence on the muscle load in neck and shoulder regions. However, the productivity was significant lower when using the 8 points characters compared with 12 points. There was also a tendency to an increase in the number of errors made.

Visual challenges using Visual Display Units (VDU) in office landscapes

A total of 85 VDU operators, in three main Scandinavian Alcatel-Lucent headquarters, were followed in a process moving from single occupancy offices to an office landscape. This paper discusses the visual challenges and implications in such a transfer. In the oral presentation recommendation on how to avoid visual problems will be given.