No / Visual impairment is an important risk factor for falls. However, relatively little is known about how visual impairment affects stair or step negotiation. The aim of the present study was to determine the effects of blurred vision on the mechanics of landing during stepping down by the elderly. Twelve elderly subjects (72.3±4.7 year) stepped down from three levels (7.2 cm, 14.4 cm and 21.6 cm). Step execution time, ankle and knee joint angular displacements at the instance of ground contact, and vertical landing stiffness and the amount of bodyweight supported by the contralateral (support) limb during the initial contact period were recorded. Measurements were repeated with vision blurred by light scattering lenses. With blurred vision, step execution time increased (P<0.05), knee flexion and ankle plantar-flexion increased (P<0.05), vertical stiffness decreased (P<0.01), and the amount of bodyweight being supported by the contralateral leg increased (P<0.05). These findings suggest that under conditions of blurred vision, subjects were more cautious and attempted to ‘feel’ their way to the floor rather than ‘drop’ on to it. This may have been an adaptation to increase the kinaesthetic information from the lower limb to make up for the unreliable or incomplete visual information. Correcting common visual problems such as uncorrected refractive errors and cataract may be an important intervention strategy in improving how the elderly negotiate stairs.

No / PURPOSE: The risk of falling increases dramatically with age, and visual impairment is known to be an important risk factor. Therefore, it is highly pertinent to assess the effects of age and vision on the performance of everyday tasks linked to falling, such as stepping from one level to another. METHODS: Nine young (age, 26 +/- 4 years) and ten elderly (age, 72 +/- 5 years) subjects performed a stepping-up task of three different heights. Their stepping strategies with blurred and optimally corrected vision were compared. Center of mass (CM), center of pressure (CP) dynamics (in the mediolateral and anteroposterior directions), and foot clearance parameters were determined, and statistical regression modeling was applied. RESULTS: Elderly subjects spent 20% more time (P = 0.03) than young subjects during double support and they had reduced anteroposterior CM-CP divergence (P < 0.001) during double support and slower anteroposterior (P < 0.001) and mediolateral (P = 0.002) CM velocities during initiation of movement and single limb support. Blur caused similar adaptations, such as increased toe clearance, across both age groups, though mediolateral (ML) CM-CP divergence in elderly subjects was significantly more reduced than in young subjects (P < 0.001). CONCLUSIONS: Findings indicate, in general, that older subjects used a more cautious and controlled stepping strategy. However, the lack of significant age differences in toe clearance suggests this strategy was mainly aimed at reducing ML instability rather than increasing margins of safety regarding toe clearance.

Yes / Purpose: The aim of this study was to systematically review the literature to investigate the link (if any) between vision and dizziness. Methods: Medline, CINAHL, AMED, Web of Science and The Cochrane Library were searched with keywords chosen to find articles which investigated the causes of dizziness and considered vision as a possible trigger. Citation chaining of all included papers was performed in addition to the hand searching of all reference lists. Unpublished literature was identified using www.opengrey.eu. The review considered studies involving adults which link, measure or attempt to improve any aspect of vision in relation to dizziness. Results: Nine thousand six hundred and eighty one possible references were found, and the abstracts were screened independently by two reviewers to determine if they should be included in the study. Thirteen papers were found which investigated whether dizziness was linked to an assessment of vision. Visual impairment measures were crude and typically self-report, or Snellen visual acuity with little or no measurement details. Five studies found an independent link between dizziness and vision, five found a weak association (typically finding a link when univariate analyses were used, but not when multivariate analyses were used), and three found no association. Studies finding a strong link were usually cross-sectional with a large study population whereas those finding a weak association had relatively small numbers of participants. Studies which did not find an association used a broad definition of dizziness that included the term light-headedness, an unreliable Rosenbaum near visual acuity chart or an unusual categorisation of visual acuity. Conclusions: This review suggests that dizziness (although likely not ‘light-headedness’) is linked with poor vision although further studies using more appropriate measures of vision are recommended. / Deborah Armstrong was funded by a College of Optometrists Research Scholarship and Emily Charlesworth by a College of Optometrists summer studentship.

No / Visual impairment is an important risk factor for falls, but relatively little is known about how it affects stair negotiation. The present study determined how medio-lateral (ML) dynamics of stepping and single limb support stability when stepping up or down to a new level were affected by blurring the vision of healthy elderly subjects. Twelve elderly subjects (72.3±4.2years) were analysed performing single steps up and single steps down to a new level (7.2, 14.4 and 21.6cm). Stepping dynamics were assessed by determining the ML ground reaction force (GRF) impulse, lateral position of the centre of mass (CM) relative to the supporting foot (average horizontal ML distance between CM and CP during single support) and movement time. Stability was determined as the rms fluctuation in ML position of the centre of pressure (CP) during single support. Differences between optimal and blurred visual conditions were analysed using a random effects model. Duration of double and single support, and the ML GRF impulse were significantly greater when vision was blurred, while the average CM¿CP ML distance and ML stability was reduced. ML stability decreased with increasing step height and was further decreased when stepping down than when stepping up. These findings indicate that ML balance during stepping up and down was significantly affected by blurring vision. In particular, single limb support stability was considerably reduced, especially so during stepping down. The findings highlight the importance of accurate visual feedback in the precise control of stepping dynamics when stepping up or down to a new level, and suggest that correcting common visual problems, such as uncorrected refractive errors and cataract may be an important intervention strategy in improving how the elderly negotiate stairs.

The purpose of this qualitative study was to explore self-determination in daily life and external programs for youth with visual impairments. To achieve this, the researcher explored three areas that contribute to the development of self-determination based on Wehmeyer’s Functional Theory of Self-determination: capacity, opportunities, and support. All participants in this study participated in Cane Quest, an external program specifically designed for youth with visual impairments. Cane Quest is a long cane competition for youth with visual impairments. These youth independently complete on a route using their orientation and mobility skills while navigating through complex environments such as residential areas, commercial areas, stores, buses, and a college campus. Data were collected through individual interviews, focus group sessions, and document collection. The phenomenological approach was used to analyze the data. Results suggest that youth with visual impairments are facing barriers to capacity, opportunities, and appropriate support in their daily lives. The finding also identified that external programs, like Cane Quest, can provide opportunities and appropriate support for youth with visual impairments to practice and develop self-determination skills. External programs, such as Cane Quest, can be beneficial for youth with visual impairments by filling in some of the gaps that may be occurring in their daily lives.

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No description available.

Diets containing 5.0% excess phenylalanine; 6.0% excess protein (gelatin), and limited in tryptophan (75mg/lOOg) and/or vitamin E (O.lmg/IOOg) were fed to male rats during gestation and lactation. Addition of 5.0% phenylalanine result in a greater incidence of cataract than studies previously reported with diets limited in tryptophan and vitamin E alone, or a single supplementation of Vitamin E (40.0.mg/lOOg). Supplementation with tryptophan (500mg/lOOg) and vitamin E (40.0mg/100g) prevented cataract formation. Replacing the 5.0% excess phenylalanine and 6.0% excess protein (gelatin) with an equivalent of a balanced free amino acid mixture prevented cataract formation in the group supplemented with vitamin E alone. Addition of balanced free amino acids resulted in decreased fertility, pup survival, and increased diuresis. Supplementation with vitamin E (40.0mg/lOOg) alone prevented these effects. Urinary excretions of keto acid (phenylpyruvate), nitrogen, urea, and creatinine were examined during the 7-l4th days of gestation. Amino acid analysis were performed on plasma and soluble lens hornogenates from young progeny. Protein separations of soluble lens homogenates from young progeny were obtained. Analysis of these parameters did not indicate distinct differences between cataractous and noncataractous groups. / Master of Science

This thesis is based on five empirical studies of pupils with visual impairments, their reading ability and processes of reading acquisition within the framework of mainstream education in comprehensive schools. The aim of the thesis is to increase our understanding and knowledge of reading acquisition in pupils with visual impairments in mainstream education. A further aim is to find factors, which influence reading acquisition from an individual, as well as an environmental, perspective. Developmental theories regarding the individuals' possibilities to acquire an optimal development in interaction with their environment offer a theoretical framework for the thesis. Different research designs, descriptive and explorative, have been used to fulfil the purpose. The studies have revealed a heterogeneous group of readers with visual impairments bearing in mind functional visual ability, reading media (print and braille) and reading ability. As a result of these studies, it was possible to divide the readers into three groups with regard to reading performance. About one quarter of the population was average or high achievers, another quarter extremely low achievers, irrespective of visual acuity, reading media or reading devices. In most cases, additional impairments, intellectual impairment or language problems caused low achievement. The largest group, about half of the population, consisted of readers who were able to read but demonstrated difficulties in other ways. Visual acuity and reading media varied greatly in this group. There were uncertain readers, readers with low reading rate but good comprehension, readers with less stamina and readers who did not use their reading ability except for schoolwork. The pupils were well equipped with optical devices, lighting and special desks but seldom used the facilities for reading. In general, the pupils with visual impairments read less compared with their sighted peers. Nor were they exposed to text in natural situations in society, which decrease their incidental reading training. Consequently, a large group of readers with visual impairments need an adapted reading program in order to stimulate reading from the start and to use their potential ability. Competence in the school and home environment is necessary for compensating lack of training and preventing the visual impairment being the reason for reading difficulties. Reading disabilities due to biological factors were significant for a smaller group. Visual impairment as a reading handicap is, in this thesis, identified when a person, able to read, does not have access to the text in an appropriate reading medium or format, reading and writing tools are missing or reading must be performed in a badly adapted environment. Increased knowledge and effective environmental measures could reduce a reading handicap caused by a visual impairment for a larger group of children and young people. / <p>Härtill 5 uppsatser. Endast sammanfattning s. 1-93 i fulltext.</p><p></p>

The goal of this study was to explore the psychosocial aspects within the workplace of people with visual impairment, after mobility training at Optima College Pretoria. The objectives of this study were: To build up a theoretical framework by means of a literature study as well as consultation with experts on the psychosocial aspects of people with visual impairment within the workplace after mobility training at Optima College. To conduct an empirical study of the psychosocial aspects of people with visual impairment within the workplace after mobility training at Optima College. To come to conclusions and to make recommendations for improved adaptation of people with visual impairment within the workplace. This qualitative study endeavoured to answer the following research question: What are the psychosocial aspects experienced by people with visual impairment within the workplace and what are the viewpoints of supervisors and colleagues in this regard? By answering this question, the researcher aimed to document these experiences to understand the phenomenon and to make recommendations for improved adaptation within the workplace. Non-probability sampling methods were used to select the five respondents. Data was gathered by conducting interviews, using semi-structured interview schedules with five people with visual impairment, as well as a supervisor and colleague for each of the five respondents. These interviews were taped and transcribed and subsequently analysed, extracting themes as well as sub-themes. The study was feasible, as it was within the financial and practical means of the researcher. She had access to the target group and she had permission from Optima College to conduct the study, using their resources, clients and data. Five main themes emerged from the data analysis, namely: 1.The adaptation at Optima College and the experience of the training 2.Adaptation at the workplace and investments made by the employers 3.Psychosocial aspects experienced within the workplace as well as in the community 4.The experiences of the supervisor of the person with visual impairment 5.The experiences of the colleague of the person with visual impairment. From the research findings, recommendations were made on micro, macro and meso-levels. On micro-level, people with visual impairment can play a role by telling supervisors and colleagues about their needs and problems. On macro-level, recent employers of people with visual impairment can motivate other employers to employ people with visual impairment. When stigmatization as well as prejudices are removed from society, employers will be more motivated to employ people with visual impairment. On meso-level, Optima College, the South African National Council for the Blind, as well as public media, can play a leading role in publishing positive articles regarding people with visual impairment in the workplace. Optima College must continue with the training of people with visual impairment. / Dissertation (MSD (Health Care))--University of Pretoria, 2006. / Social Work and Criminology / Unrestricted