introduction: contrast sensitivity is one of the most important psychophysical tests that may be used for the evaluation of refractive state of eye and retinal image quality. yellow vs. blue color contrast sensitivity may be more suitable in this regard. materials and methods: thirty myopic eyes were considered in this study. yellow vs. blue color contrast sensitivity was evaluated under the sa...

Optical aberrations lead to defects in image-forming, the image obtained being imperfect and thereby decreasing the quality of vision. When an optic system is not perfect, as happens with the eye, the rays of light that pass through the system produce optical aberrations. The purpose of this review is to describe optical aberrations and their impact on vision and how refractive surgery outcomes...

In this paper we experimentally demonstrate the proof of concept for predictive control of thermally induced wavefront aberrations in optical systems. On the basis of the model of thermally induced wavefront aberrations and using only past wavefront measurements, the proposed adaptive optics controller is able to predict and to compensate the future aberrations. Furthermore, the proposed contro...

Purpose The human eye has typically more optical aberrations than conventional artificial optical systems. While the lower order modes (defocus and astigmatism) are well studied, our purpose is to explore the influence of genes versus the environment on the higher order aberrations of the optical components of the eye. Methods We have performed a classical twin study in a sample from the Regi...

PURPOSE To compare experimental optical performance in eyes implanted with spherical and aspheric intraocular lenses (IOLs). METHODS Corneal, total, and internal aberrations were measured in 19 eyes implanted with spherical (n=9) and aspheric (n=10) IOLs. Corneal aberrations were estimated by virtual ray tracing on corneal elevation maps, and total aberrations were measured using a second-gen...

PURPOSE To evaluate the optical aberrations induced by LASIK refractive surgery for myopia on the anterior surface of the cornea and the entire optical system of the eye. METHODS Total and corneal aberrations were measured in a group of 14 eyes (preoperative myopia ranging from -2.5 to -13 D) before and after LASIK surgery. Total aberrations were measured using a laser ray-tracing technique. ...

This work presents a study of the influence and compensation of aberrations in optical imaging systems by superimposing surfaces described by Zernike polynomials. The aim is to investigate how to compensate for aberrations and their effectiveness when dealing with aberrations of different types. The study is done in the Zemax packet by modeling the optical imaging system and passing test images...

SEPTEMBER 2010 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 35 T he introduction of wavefront-sensing techniques to ophthalmology has redefined the clinical meaning of refractive error. Now, all imperfections in the components and materials within the eye that cause light rays to deviate from their desired path are referred to as optical aberrations. Lower-order aberrations (defocus and astigmati...

Keratoconus causes a reduction in the optical quality of the eye as a result of corneal distortion, corneal scarring and higher-order aberrations. The correction of these optical aberrations would significantly improve the visual performance of keratoconic eyes. However the first step would be to measure the optical flaws in keratoconus accurately, which in itself presents a challenge. This pap...