This research is about evaluating vision in the periphery. Peripheral vision is of fundamental importance in the performance of our everyday activities. The aim of this thesis is to develop methods suitable for the evaluation of peripheral vision and to assess how different visual functions vary across the visual field. The results have application both within the field of visual rehabilitation of people with central visual field loss (CFL)and as well as in myopia research. All methods for assessing peripheral vision were implemented with adaptive psychophysical algorithms based on Bayesian statistics. A routine for time-efficient evaluation of peripheral contrast sensitivity was implemented and verified for measurements out to 30° in the visual field. Peripheral vision was evaluated for different properties of the stimuli: sharpness, motion, orientation, and extent. Optical quality was controlled using adaptive optics and/or corrective spectacles specially adapted for the peripheral viewing angle. We found that many peripheral visual functions improved with optical correction, especially in people with CFL. We also found improvements in peripheral contrast sensitivity for low spatial frequencies when stimuli drifted at 5 to 10 Hz; this applies both for people with normal vision and those with CFL. In the periphery, it is easier to see lines that are oriented parallel with respect to the visual field meridian. We have shown that this directional bias is present for both resolution and detection tasks in the periphery, even when the asymmetric optical errors are minimized. For accurate evaluation of peripheral vision, we therefore recommend using gratings that are oriented oblique to the visual  field meridian. The directional bias may have implications in how peripheral image quality affects myopia progression. Another proof that peripheral vision can influence central visual function is the fact that, when the stimulus extent was increased beyond the fovea, the blur in the stimulus was less noticeable. / Denna forskning handlar om att utvärdera synen i periferin. Vår perifera syn är ovärderlig i det dagliga livet. Målsättningen med denna avhandling är dels att utveckla metoder speciellt lämpade för perifer synutvärdering och dels att mäta hur olika synfunktioner varierar över synfältet. Resultaten har tillämpning både inom synrehabilitering för personer med centraltsynfältsbortfall och inom närsynthetsforskning. Adaptiv psykofysisk metodologi baserad på Bayesiansk statistik användes vid all utvärdering av det perifera seendet. Vi implementerade en rutin för tidseffektiv mätning av perifer kontrastkänslighet och verifierade den ut till 30° i synfältet. Den perifera synen utvärderades för olika egenskaper hos objektet: skärpa, rörelse, riktning och utbredning. Skärpan kontrollerades med hjälp av adaptiv optik och/eller glasögonkorrektion speciellt anpassad för den perifera synvinkeln. Vi fann att många periferasynfunktioner förbättras av optisk korrektion, särskilt för personer med centralt synfältsbortfall. Vi hittade även förbättringar i periferkontrastkänslighet för låga ortsfrekvenser när objektet modulerades med hastigheter mellan 5 och 10 Hz, vilket gäller både normalseende och personer med centralt synfältsbortfall. I periferin är det lättare att se linjer som är orienterade parallellt med synfältsmeridianen. Vi har visat att denna riktningsbias gäller både för upplösning och detektion i periferin, även när de asymmetriska optiska felen minimeras. För bästa mätnoggrannhet rekommenderar vi därför att använda randmönster som ligger snett relativt synfältsmeridianen. Denna riktningsbias skulle även kunna påverka hur den perifera bildkvalitén inverkar på utvecklingen av närsynthet. Ytterligare ett bevis för att perifer syn kan påverka den centrala synfunktionen är att, när objektets utbredning ökades, uppfattade personen det som mindre suddigt. / <p>QC 20160826</p>

INTRODUÇÃO: A falta da correção óptica recentemente foi reconhecida como importante causa de baixa visão e parece ser um problema fácil de ser resolvido com o uso de óculos. No entanto, a falta da correção óptica é um problema complexo do seu diagnóstico ao tratamento, envolvendo a procura e alcance da assistência médica, além da confecção e uso dos óculos. OBJETIVOS: Determinar a frequência da necessidade de correção óptica em escolares; determinar a influência do absenteísmo no estudo da frequência da necessidade de correção óptica e suas causas; determinar o impacto da reconvocação dos faltosos na cobertura do atendimento oftalmológico; verificar cobertura oftalmológica prévia; verificar uso da correção óptica prescrita e causas de abandono de óculos. MÉTODO: Foi realizado um estudo transversal analítico. Escolares de 7 a 10 anos do ensino público de Guarulhos foram triados e encaminhados para exame oftalmológico na Campanha Olho no Olho 2006 e 2007. RESULTADOS: Foram triados 40.197 escolares e encaminhados 11.741 escolares com suspeita de problemas visuais. O absenteísmo na primeira convocação foi 42.5% e na reconvocação foi 62.2%. A Campanha alcançou 73.6% dos escolares encaminhados. A reconvocação ampliou a cobertura do projeto em 16.1%. A falta de orientação (não ter recebido aviso ou guia de encaminhamento) foi a razão mais frequente (35.6%) alegada para o não comparecimento, seguida de trabalho (20.6%) e doença (12.4%). A necessidade de óculos não foi fator associado ao comparecimento. Para 60.2% dos escolares foi a primeira oportunidade de exame ocular, sendo que 27.3% procuraram mas não tiveram acesso a consulta médica. Dos 1.379 escolares que já haviam feito exame, 48.3% utilizaram o SUS e 1.029 receberam prescrição de óculos em exame prévio. Destes, 899 (87.4%) fizeram os óculos e apenas 590 (57.3%) usavam os óculos no dia do exame. Dos óculos doados na Campanha, 84.7% dos escolares utilizavam a correção óptica após um ano. A estimativa da frequência da necessidade de correção óptica, na população estudada, foi de 6.9%. CONCLUSÕES: O erro refracional não corrigido foi a maior causa de baixa acuidade visual entre os escolares. A Campanha foi a primeira oportunidade de exame ocular para a maioria dos escolares. Existe uma parcela de pais que não leva seus filhos para exame, mesmo com oferecimento de facilidades (acesso, transporte, alimentação, duas oportunidades diferentes de exame gratuito realizado em fins de semana e doação de óculos). O absenteísmo poderia ser evitado em 87,1% dos casos, com melhor estruturação da primeira convocação. A reconvocação não é recomendada quando os recursos financeiros são escassos / INTRODUCTION: The lack of optical correction was recently recognized as an important cause of low vision and it seems to be an easy problem to be solved with the use of spectacles. However, it is a complex problem from its diagnosis to treatment, which includes medical assistance searching and finding, and spectacles acquisition and use. PURPOSES: To determine the frequency of optical correction need; to determine the impact of the recall of those absent in the ophthalmologic service coverage and its causes; to check the previous ophthalmologic coverage; to check the use of the prescribed optical correction and causes to neglect the use of spectacles. METHOD: An analytical cross-sectional study was conducted. Students between 7 and 10 years old of public education from Guarulhos were screened and referred to ophthalmologic exam in the Eye to Eye Campaign 2006 and 2007. RESULTS: 40.197 students were screened and 11.741 (29,2%) were referred with suspicion of visual problems. The absenteeism in the first call was 42.5% and in the recall 62.2%. The Campaign reached 73.6% of the referred students. The recall expanded the project coverage in 16.1%. The lack of guidelines (parents did not receive notification or referral guide) was the most frequent reason (35.6%) provided by parents for the non attendance, followed by work (20.6%) and disease (12.4%). The need of glasses was not related to the attendance. For 60.2% of the students, it was the first opportunity for ophthalmological exam, whereby 27.3% searched but did not have access to a medical visit. Among the 1.379 students who had already performed an exam, 48.3% used the Public Health System and 1.029 received prescription of glasses in the previous exam. From those, 899 (87.4%) made their glasses and only 590 (57.3%) were wearing glasses on the day of the exam. From the donated spectacles in the Campaign, 84.7% of the students were using the donated optical correction after one year. The estimate of optical correction need within the studied population was 6.9%. CONCLUSIONS: The uncorrected refractive error was the main cause of low visual acuity among students. The Campaign was the first opportunity of ocular exam for most of them. A significant number of parents did not take their children for ophthalmological exams, even when facilities (access, free transportation, meal, two different opportunities of free exam over the weekend and spectacle donation) were offered. For 87.1% of the absenteeism cases, the difficulties could have been overcome via improved structuring of the first call. A recall is not recommended when financial resources are low

This work builds up on the greatest minds of Cambridge Holography: Adrian Cable, Edward Buckley, Jonathan Freeman, and Christoph Bay. Cable and Buckley, developed an OSPR algorithm which was the first to provide high-quality real-time hologram generation using general-purpose hardware while Freeman designed a method to correct arbitrary aberrations. As ingenious as the method was, the calculations were extensively lengthy. Addressing this issue, a variant of OSPR suited for correcting spatially-varying aberration is presented. The algorithm combines the approaches of Cable, Buckley and Freeman to provide real-time hologram generation while incorporating various corrections (aberration, distortion, and pixel shape envelope). A high-performance implementation on a mid-range GPU achieved hologram generation up to 12 fps. Following topic studied is an adaptive optical correction. This work attempts to construct a set of methods, forming an automated testbed for holographic projectors. Each model, after exiting the production line is placed on such testbed, having all of its imperfections characterized. Once calibrated, each model is able to display highest-quality image throughout its life-span. An application of this work to industry was carried in collaboration with Dr Phillip Hands (University of Edinburgh) and LumeJET. Three demonstrators are constructed intending for a cost-effective system for holographic lithography. They are characterized using the developed testbed. Using the supersampled Adaptive OSPR algorithm, the diffraction limit was surpassed 2.75 times allowing to increase the patterning area. This combines approaches of Cable, Buckley, Freeman and Bay to achieve a wide field-of-view and high pixel-count replay field using off-the-shelf components. This thesis is finished describing the work on 3D holography carried with Penteract28. It is shown that the 2D hologram in the presence of spatially-varying aberrations is mathematically equivalent to a 3D hologram. The same implementation of the algorithm can be used to provide real-time 3D hologram generation.

INTRODUÇÃO: A falta da correção óptica recentemente foi reconhecida como importante causa de baixa visão e parece ser um problema fácil de ser resolvido com o uso de óculos. No entanto, a falta da correção óptica é um problema complexo do seu diagnóstico ao tratamento, envolvendo a procura e alcance da assistência médica, além da confecção e uso dos óculos. OBJETIVOS: Determinar a frequência da necessidade de correção óptica em escolares; determinar a influência do absenteísmo no estudo da frequência da necessidade de correção óptica e suas causas; determinar o impacto da reconvocação dos faltosos na cobertura do atendimento oftalmológico; verificar cobertura oftalmológica prévia; verificar uso da correção óptica prescrita e causas de abandono de óculos. MÉTODO: Foi realizado um estudo transversal analítico. Escolares de 7 a 10 anos do ensino público de Guarulhos foram triados e encaminhados para exame oftalmológico na Campanha Olho no Olho 2006 e 2007. RESULTADOS: Foram triados 40.197 escolares e encaminhados 11.741 escolares com suspeita de problemas visuais. O absenteísmo na primeira convocação foi 42.5% e na reconvocação foi 62.2%. A Campanha alcançou 73.6% dos escolares encaminhados. A reconvocação ampliou a cobertura do projeto em 16.1%. A falta de orientação (não ter recebido aviso ou guia de encaminhamento) foi a razão mais frequente (35.6%) alegada para o não comparecimento, seguida de trabalho (20.6%) e doença (12.4%). A necessidade de óculos não foi fator associado ao comparecimento. Para 60.2% dos escolares foi a primeira oportunidade de exame ocular, sendo que 27.3% procuraram mas não tiveram acesso a consulta médica. Dos 1.379 escolares que já haviam feito exame, 48.3% utilizaram o SUS e 1.029 receberam prescrição de óculos em exame prévio. Destes, 899 (87.4%) fizeram os óculos e apenas 590 (57.3%) usavam os óculos no dia do exame. Dos óculos doados na Campanha, 84.7% dos escolares utilizavam a correção óptica após um ano. A estimativa da frequência da necessidade de correção óptica, na população estudada, foi de 6.9%. CONCLUSÕES: O erro refracional não corrigido foi a maior causa de baixa acuidade visual entre os escolares. A Campanha foi a primeira oportunidade de exame ocular para a maioria dos escolares. Existe uma parcela de pais que não leva seus filhos para exame, mesmo com oferecimento de facilidades (acesso, transporte, alimentação, duas oportunidades diferentes de exame gratuito realizado em fins de semana e doação de óculos). O absenteísmo poderia ser evitado em 87,1% dos casos, com melhor estruturação da primeira convocação. A reconvocação não é recomendada quando os recursos financeiros são escassos / INTRODUCTION: The lack of optical correction was recently recognized as an important cause of low vision and it seems to be an easy problem to be solved with the use of spectacles. However, it is a complex problem from its diagnosis to treatment, which includes medical assistance searching and finding, and spectacles acquisition and use. PURPOSES: To determine the frequency of optical correction need; to determine the impact of the recall of those absent in the ophthalmologic service coverage and its causes; to check the previous ophthalmologic coverage; to check the use of the prescribed optical correction and causes to neglect the use of spectacles. METHOD: An analytical cross-sectional study was conducted. Students between 7 and 10 years old of public education from Guarulhos were screened and referred to ophthalmologic exam in the Eye to Eye Campaign 2006 and 2007. RESULTS: 40.197 students were screened and 11.741 (29,2%) were referred with suspicion of visual problems. The absenteeism in the first call was 42.5% and in the recall 62.2%. The Campaign reached 73.6% of the referred students. The recall expanded the project coverage in 16.1%. The lack of guidelines (parents did not receive notification or referral guide) was the most frequent reason (35.6%) provided by parents for the non attendance, followed by work (20.6%) and disease (12.4%). The need of glasses was not related to the attendance. For 60.2% of the students, it was the first opportunity for ophthalmological exam, whereby 27.3% searched but did not have access to a medical visit. Among the 1.379 students who had already performed an exam, 48.3% used the Public Health System and 1.029 received prescription of glasses in the previous exam. From those, 899 (87.4%) made their glasses and only 590 (57.3%) were wearing glasses on the day of the exam. From the donated spectacles in the Campaign, 84.7% of the students were using the donated optical correction after one year. The estimate of optical correction need within the studied population was 6.9%. CONCLUSIONS: The uncorrected refractive error was the main cause of low visual acuity among students. The Campaign was the first opportunity of ocular exam for most of them. A significant number of parents did not take their children for ophthalmological exams, even when facilities (access, free transportation, meal, two different opportunities of free exam over the weekend and spectacle donation) were offered. For 87.1% of the absenteeism cases, the difficulties could have been overcome via improved structuring of the first call. A recall is not recommended when financial resources are low