Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 31 for “"Refractive error"”.
-
Validation and Repeatability of Pediatric Refractive Error Profile 2 (PREP2)
Many myopia control studies use refractive correction as a means to slow axialgrowth. The Pediatric Refractive Error Profile (PREP) is a survey used to measure qualityof life of children wearing refractive correction and can be used in these studies. ThePREP2 is an updated version of this survey. …
-
User accessibility to refractive error correction services in selected Zambian hospitals
Background: Uncorrected Refractive Errors (UREs) are the most common cause of vision loss globally. The burden is particularly worse in low- and middle-income countries like Zambia, where access to Refractive Error Correction Services (RECS) is limited. This study aimed to assess the user's …
-
School vision screening programmes: the benefits of including measurements of refractive error.
… attention has been paid to the role of detecting refractive error namely hyperopia thus far. The purpose of this thesis was to determine the benefits of including a refractive error assessment at vision screening. The value of including a refraction was investigated by retrospectively analysing …
-
School Vision Screening Programs In Reducingchildren With Uncorrected Refractive Error In Low And Middle-income Countries (Lmic)(Systematic Review)
Background: The prevalence of uncorrected refractive error among school-age children is on the rise with a detrimental effect on academic performance and socio-economic status of those affected. School vision screening appears to be an effective way of identifying children with uncorrected …
-
Ocular biometric change in orthokeratology. An investigation into the effects of orthokeratology on ocular biometry and refractive error in an adult population.
… on a number of biometric parameters and refractive error in an adult population. Method; Forty three myopic subjects were recruited to a twelve month study into the effects of orthokeratology on ocular biometry and refractive error. Two different back surface lens designs were applied …
-
Peripheral Refractive Error and its Association with Myopia Development and Progression. An examination of the role that peripheral retinal defocus may play in the origin and progression of myopia
… myopia progression by manipulating peripheral refractive error. This study proposed to establish the distribution of peripheral refractive errors in hyperopic, emmetropic and myopic children and to test the hypothesis that relative peripheral hyperopia is a risk factor in the onset and …
-
The Labrador Retriever as a Model of Naturally Occurring Myopia: Genetic and Environmental Contributions
… of Labrador Retrievers was phenotyped for refractive error. Using statistical (familial aggregation) analysis, refractive error data was used to investigate the inheritance of the trait within the pedigree. DNA samples were taken for later analysis. Potential environmental factors early in …
-
Refractive error, ocular biometry and oculomotor function: The prevalence of myopia and its potential risk factors in the Middle East, with an investigation of dynamic accommodation responses and axial length fluctuations in young myopic adults.
… a cross-sectional study of the prevalence of refractive error and its biometric correlates in Middle Eastern adults. In addition dynamic accommodative responses and twenty-four hour axial length fluctuations were investigated in young myopic adults. The prevalence of myopia in 3000 Middle …
-
Influence of ocular monochromatic aberrations in the development and/or progression of myopia
… ocular aberrations and a myopic change in refractive error using the data obtained longitudinally. Methods: On and off-axis aberrations of cyclopleged eyes (5 mm pupil diameter) of 646 children were measured during 2004-2005 (age, 12.7 ± 0.4 years) and 5 years later in 2009-2010 (age, 17.1 …
-
The Role of the crystalline lens in ametropia
… found that some may vary with different types of refractive error. The effects of several of these variations on refractive error are investigated in this thesis. To examine whether lens thickness was significantly different in youth-onset myopes compared with emmetropes, a structural model was …
-
Influence of Light Exposure on the Melanopsin Driven Pupil Response and Circadian Rhythm
… suggests that light exposure plays a role in refractive error development. This study sought to investigate whether melatonin level and sleep quality can be modulated by decreasing nighttime input to the ipRGCs. Another goal was to investigate links between light exposure, ipRGCs, refractive …
-
Visual Function in New Zealand Children: from Preschool to Primary School
… childhood vision conditions. Uncorrected refractive error is the leading cause of visual impairment in children and has been associated with reduced academic performance. This thesis investigated the role of the current preschool vision screening programme in detecting vision conditions, …
-
Modeling Of Mouse Eye And Errors In Ocular Parameters Affecting Refractive State
<p>ABSTRACT</p> <p>MODELING OF MOUSE EYE AND ERRORS IN OCULAR PARAMETERS AFFECTING REFRACTIVE STATE</p> <p>by</p> <p>GURINDER BAWA</p> <p>September 2013</p> <p>Advisor: Dr. Ivan Avrutsky</p> <p>Major: Electrical Engineering</p> <p>Degree: Doctor of Philosophy</p> <p>Rodents eye are particularly …
-
Prevalence and risk factors of myopia among Grade 8 learners in Vhembe District
Myopia is not a simple refractive error but an eyesight-threatening disorder. The disorder has a great impact on public health and the socio-economic well-being of people, particularly children. The aim of this study was to investigate the prevalence of myopia and the risk factors associated with …
-
Lasting effects of atlanto-axial manipulation on edge light pupil cycle time
… constant, unaffected by visual acuity, refractive error, eye colour, pupil size or gender. Recent studies have shown that high-velocity manipulation of the upper cervical spine causes an immediate decrease in ELPCT on the same side as the manipulation. This change is presumed to me …
-
The Effect of Age on Dark Focus Distance and Visual Information Transfer Rate
… is still unknown. Previous studies suggest that refractive error is minimal at the intermediate resting point of accommodation — i.e., at the dark focus distances. Additionally, aging is closely linked to increased refractive error. In order to assess the effects of age on dark focus distance and …
-
Structural and functional aspects of myopia in young adults. An investigation of nearwork-induced transient myopia and accommodation in relation to refractive stability.
… and accommodation responses in relation to refractive stability, multichromatic stimuli and orthokeratology. Five individual studies have been carried out. Initially an investigation into the temporal and dioptric aspects of nearwork-induced transient myopia was undertaken, suggesting that …
-
The Effects of Low Intensity Ambient Lighting on Refractive Development in Rhesus Monkeys (Macacca mulatta)
… alterations in ambient lighting levels influence refractive development. The purpose of the studies reported in this dissertation was to evaluate the extent to which low ambient lighting influences refractive development in primates and to determine whether and how low ambient lighting levels …
-
Smart photonics in imaging and sensing
… is also presented and demonstrated for myopic refractive error vision corrections from zero to -5 Diopters. In addition, a novel eyewear design is also proposed which uses aperture control for vision correction. Sensor applications are discussed next, including design of an agile wavelength …
Page 1 of 2