Browsing by Subject "Aberrations"

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    Focus correction in an apodized system with spherical aberration
    (Optica Publishing Group, 2015-07-24) Bernal Molina, Paula; Castejón Mochón, José Francisco; Bradley, Arthur; López Gil, Norberto; Didáctica de las Ciencias Matemáticas y Sociales
    We performed a theoretical and computational analysis of the through-focus axial irradiance in a system with a Gaussian amplitude pupil function and fourth- and sixth-order spherical aberration (SA). Two cases are analyzed: low aberrated systems, and the human eye containing significant levels of SA and a natural apodization produced by the Stiles–Crawford effect. Results show that apodization only produces a refraction change of the plane that maximized the Strehl ratio for eyes containing significant levels of negative SA.
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    Optical and visual metrics.
    (Taylor & Francis Group, LLC., 2017) Guirao, Antonio; Física
    The eye is a complex imaging system whose optical components determine the first step of vision. Quantifying and measuring the ocular quality, and how this affects the quality of the retinal images, can allow us to better understand the visual process and to improve diagnostics and correction methods. The optical quality is lowered by aberrations (consequence of the shape of the refracting surfaces), diffraction at the pupil, and scattering (due to particles and nonuniformities localized in the media). The combined effect of these three factors is that light deviates from the ideal trajectory and spreads over a deteriorated retinal image that will limit the visual performance. In general, a system with less aberrations, scattering, and diffraction will produce images with higher quality. Consequently, one expects to have a better vision when images at the retina are fine. However, although the optics, the retinal image stage, and the visual perception are dependent with each other, there is not a direct or obvious relationship between these three levels. In this context, it is necessary to distinguish between optical quality, optical performance (image quality), and visual performance and to be able to define metrics that quantitatively measure each of these matters