نتایج جستجو برای: corneal wavefront aberration

تعداد نتایج: 38950  

Journal: :Applied optics 2014
Visa Korkiakoski Christoph U Keller Niek Doelman Matthew Kenworthy Gilles Otten Michel Verhaegen

We present two complementary algorithms suitable for using focal-plane measurements to control a wavefront corrector with an extremely high-spatial resolution. The algorithms use linear approximations to iteratively minimize the aberrations seen by the focal-plane camera. The first algorithm, Fast & Furious (FF), uses a weak-aberration assumption and pupil symmetries to achieve fast wavefront r...

2016
Ali Mirzajani Sattar Aghataheri Mohammad Ghoreishi Ebrahim Jafarzadepour Mohadese Mohammadinia

PURPOSE This study reports the characteristics of corneal higher order aberrations (HOAs) in eyes with normal topographic pattern using the Pentacam scheimpflug system. METHODS In this prospective, observational, comparative study, 165 eyes of 97 patients separated into five groups based on corneal topographic patterns were enrolled. All eyes received a comprehensive ophthalmologic examinatio...

Journal: :Journal of vision 2007
Hema Radhakrishnan W Neil Charman

This study investigates the changes in aberrations with monocular accommodation as a function of age. Second-order and higher order wavefront aberrations and pupil size were measured as a function of accommodation demand over the range of 0-4 D in the right eyes of 47 normal subjects with ages between 17 and 56 years. Higher order ocular Zernike aberrations were analyzed for the natural pupil s...

2015
Yung-Jen Lai Shu-I Yeh Huey-Chuan Cheng

PURPOSE To investigate the distribution of corneal and ocular spherical aberrations (SAs) in eyes with cataract in the Taiwanese population. METHODS Corneal and ocular SAs were measured in the central 6-mm optical zone using wavefront aberrometry. Axial length (AL) and keratometry (K) were also evaluated in each eye. RESULTS A total of 413 eyes in 234 patients were analyzed. The mean age of...

2005
Gonzalo Muyo Andy Harvey

Recent years have witnessed the development of a new imaging technique, known as wavefront coding, that employs an aspherical phase mask and post-detection electronic processing to enable high-performance imaging with far greater tolerance to defocus aberration than traditional optical imaging [1]. Various methods have been employed for synthesizing the design of wavefront-coding phase mask [1,...

Background: Optimized is a common and important method in which aberrations are created by the device and the surgeon, but high-grade aberrations are out of the surgeon's control and are induced by the device in the patient. The aim of this study was the evaluation of out-of-control high-order aberration changes before and after PRK surgery and these impact on vision outcome. Materials and meth...

Journal: :Saudi Journal of Ophthalmology 2014

Journal: :Investigative ophthalmology & visual science 2004
Antonio Guirao Jaime Tejedor Pablo Artal

PURPOSE To study the effect of small-incision cataract surgery on the optical aberrations of the cornea. METHODS Corneal topography was measured before and after cataract surgery on 70 eyes of 70 patients. Monofocal foldable IOLs were implanted after phacoemulsification through a clear-cornea, 3.5-mm incision without suture. Corneal aberrations, up to the fifth order and 6-mm pupil, were calc...

Journal: :Transactions of the American Ophthalmological Society 2005
Peter S Hersh

PURPOSE To define the corneal optics of conductive keratoplasty (CK) and assess the clinical implications for hyperopia and presbyopia management. METHODS Four analyses were done. (1) Multifocal effects: In a prospective study of CK, uncorrected visual acuity (UCVA) for a given refractive error in 72 postoperative eyes was compared to control eyes. (2) Surgically induced astigmatism (SIA): 20...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید