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.
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Showing 1 to 11 of 11 for “"Crystalline lens"”.
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The Role of the crystalline lens in ametropia
When examining the dimensions of the crystalline lens, it is 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 …
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Structural correlates of shape change in the primate crystalline lens
… fibre modification and the role of the lens capsule. Accommodation was simulated monocularly in one animal with local administration of 1/4% phospholine iodide and by dislocation in another followed by fixation by perfusion. Three types of junctional structures were observed: angle …
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Aufbau und Validierung einer digitalen Messstrecke für die dynamische Bestimmung der Krümmungsradien und der Lage der menschlichen Augenlinse unter natürlichen Sehbedingungen
… radii of curvature and the position of the human crystalline lens. There had to be determined the anterior and posterior radii of curvature of the crystalline lens as well as the decentralisation and rotation of the crystalline lens with regard to the corneal axis. The experimental setup had to …
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Transillumination techniques in ophthalmic imaging
… retro-reflection and back-illumination of the crystalline lens and cornea. To enhance phase-gradient contrast, we apply asymmetric illumination by illuminating one side of the fundus. The technique produces micron-scale lateral resolution across a 1-mm diagonal field of view. We show …
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A new catoptric system in the eyes of penaeid shrimp
… state, the distal absorbing pigment envelops the crystalline lens or portions of the crystalline tract. This pigment is either movable or fixed in different species. Proximal pigment covers the light receptor unit and the tapetal layer is contracted in some species. Dark pigment prevents …
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Influence of ocular monochromatic aberrations in the development and/or progression of myopia
… change’ versus ‘no change’ directs focus to the crystalline lens. There may be variations in crystalline lens characteristics such as asphericity, curvature, refractive index between refractive error groups and with ocular growth and needs further investigation.
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Assessment of Ocular Accommodation in Humans
… with an extended depth-of-focus intraocular lens. Using an absolute cut-off criteria of +0.30logMAR improved the repeatability and reliability of the depth-of-focus metrics over a cut-off criteria relative to the best corrected visual acuity. A swept-source anterior segment optical coherence …
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Consolidating Approaches to Maximise Outcomes and Minimise Complications of Contemporary Cataract Surgery
Cataract is an unavoidable age-change of the crystalline lens which progressively develops and causes visual impairment affecting millions worldwide. Cataract surgery with an intraocular lens, typically performed under local anaesthetic, transforms both vision and quality of life. This thesis …
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Sutured posterior chamber intraocular lenses for traumatic cataract in Africa
… manifestations of ocular trauma every year. The lens and its supporting structures, major refractive components of the eye, may be damaged in more than half of cases of severe trauma. Despite this, there is still some doubt as which is the best modality for the most successful rehabilitation of …
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Numerical modelling of ocular accommodation process
… process and pertinent changes in the lens. Secondly, given the fact that the lens material possesses both mechanical and optical gradient properties, the contributions of both gradients to the accommodative response of the lens are quantified. Results show that although the lens GRIN …
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Computer Generation of Integral Images using Interpolative Shading Techniques
… to some extent) where the focal length of the crystalline lens is adjusted to view an image. The important binocular cues are convergence and parallax. Convergence allows the observer to judge distance by the difference in angle between the viewing axes of left and right eyes when both are …