PURPOSE To determine in vitro image qualities of artificial eyes achieved with spherical, aberration-free, average spherical aberration-correcting, and customized spherical aberration-correcting IOLs in centered, decentered, and tilted positions. METHODS The in vitro performance of these IOL models was determined by optical bench measurements. The experimental setup included a laser light sou...

PURPOSE To investigate corneal spherical aberration and corneal asphericity after small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). METHODS This study enrolled 70 patients having SMILE and 64 subjects receiving FS-LASIK. The preoperative spherical equivalent (SE) was -5.83 ± 1.23 diopters (D) and -6.20 ± 1.52 D, respectively. T...

with a negative spherical aberration designed to compensate for positive spherical aberration found in the cornea of the typical cataract patient. However, these lenses depend on precise positioning. A small offset in centration may result in significant higher order aberrations such as coma, along with significant visual impairment. These negative spherical aberration IOLs are contra-indicated...

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...

Expressions for describing Gaussian beams focused by a lens with spherical aberration have been derived. Numerical results show that, when the coefficient of the spherical aberration is negative, one can obtain flattened laser irradiance at two positions along the focused field. The larger the coefficient of negative spherical aberration, the larger the flatness is. The effect of the Fresnel nu...

The in vivo spherical aberration of the lenses of 26 subjects was estimated from the measured total aberration of the eye and that predicted from the measured shape of the anterior corneal surface. Since it was only possible to estimate the aberration contribution from the posterior corneal surface, its value led to an uncertainty in the final aberration level of the lens. For all the subjects ...

PURPOSE To develop a corneal model to better explain how refractive surgery procedures induce spherical aberration. SETTING Department of Ophthalmology and Center for Visual Science, University of Rochester, Rochester, New York, USA. METHODS The preoperative cornea was modeled as a rotationally symmetric surface with various radii of curvature and asphericities. The postoperative cornea was...

purpose: to investigate the effects of surface ablation excimer surgery on higher-order aberrations and to assess the safety and efficacy of wavefront-guided surface ablation excimer surgery in patients with hyperopia and hyperopic astigmatism. methods: in this analytical & descriptive study, wavefront-guided surface ablation excimer surgery was performed in 58 eyes of 31 patients with hyperopi...

PURPOSE The aim of this study was to design and evaluate in the laboratory a new intraocular lens (IOL) intended to provide superior ocular optical quality by reducing spherical aberration. METHODS Corneal topography measurements were performed on 71 cataract patients using an Orbscan I. The measured corneal surface shapes were used to determine the wavefront aberration of each cornea. A mode...

VIII. IX. X. XI. XII. Sign Conventions Aberration-Free Image Spherical Wavefront, Defocus, and Lateral Shift Angular, Transverse, and Longitudinal Aberration Seidel Aberrations A. Spherical Aberration B. Coma C. Astigmatism D. Field Curvature E. Distortion Zernike Polynomials Relationship between Zernike Polynomials and Third-Order Aberrations Peak-to-Valley and RMS Wavefront Aberration Strehl ...