PURPOSE Corneal collagen cross-linking (CXL) is a treatment strategy used in keratoconic eyes. Evaluation of long-term changes of higher-order aberrations (HOAs) after CXL is useful in understanding the efficacy of this procedure in improving optical, refractive, and visual acuity. This study aims to investigate the long-term effect of CXL on ocular HOA in patients with progressive keratoconus ...

The chromaticity control is very important ingredient in the operation of a high energy ring accelerator. The strong nonlinear magnetic field is then necessary to correct the large chromaticity, which inevitably enhances the nonlinearity of the beam dynamics of the circular accelerator. Hence, for the purpose of precisely controlling the chromaticity, one should understand the higher order beha...

An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced...

Although the human eye has a relatively simple optical system, it is not perfect. It has been well known that the human eye suffers from the wavefront aberration that includes both lower (defocus and astigmatism) and higher order aberrations. The lower order aberration has been effectively corrected with conventional ophthalmic lenses such as spectacles and contact lenses. However, it is more c...

PURPOSE To evaluate the correlation between refractive error and higher-order aberrations (HOAs) in patients with myopic astigmatism. METHODS HOAs were measured using the Zywave II aberrometer over a 6 mm pupil. Correlations between HOAs and myopia, astigmatism, and age were analyzed. RESULTS One hundred and twenty-six eyes of 63 subjects with mean age of 26.4±5.9 years were studied. Mean s...

The ideal location for an aberration corrector in an electron-optical column is at the place where the aberration is introduced. In practice, this of course typically cannot be achieved. The resultant separation between where an aberration is introduced and where it is removed produces combination aberrations for all aberrations of higher than first order. In the case of third-order aberration ...