Photorefractive methods have become popular in the measurement of refractive and accommodative states of infants and children owing to their photographic nature and rapid speed of measurement. As in the case of any method that measures the refractive state of the human eye, monochromatic aberrations will reduce the accuracy of the measurement. Monochromatic aberrations cannot be as easily predi...

Optical distortion is one of the optical aberrations of optical systems that do not affect image sharpness. Thus, it can be beneficial to correct optical distortion computationally rather than optically. Computational correction versus optical correction will generally yields lighter optical systems. This is of great importance for head-mounted displays where the weight of the viewer needs to b...

by Christopher O. Porter Aero-optical aberrations associated with turbulent compressible flow fields can seriously degrade the performance of an optical system; the effect of these aberrations increases as the wavelength of the transiting light becomes shorter, and so is particularly strong at visible and near-infrared wavelengths. These aero-optic aberrations originate from both spatialand tem...

PURPOSE In most current aberrometers, near infrared light is used to measure ocular aberrations, whereas in some applications, optical aberration data in the visible range are required. We compared optical aberration measurements using infrared (787 nm) and visible light (543 nm) in a heterogeneous group of subjects to assess whether aberrations are similar in both wavelengths and to estimate e...

a T p HE PRESENCE OF OPTICAL ABERRATIONS THAT BLUR retinal images were the subject of popular lectures by Helmholtz in the 1860s, and led him to state: Now, it is not too much to say that if an optician wanted o sell me an instrument which had all these defects, I hould think myself justified in blaming his carelessness in he strongest terms and giving him back his instrument.”1 ecently, the av...

Sodium Laser Guide Stars (LGSs) are elongated sources due to the thickness and the finite distance of the sodium layer. The fluctuations of the sodium layer altitude and atom density profile induce errors on centroid measurements of elongated spots, and generate spurious optical aberrations in closed–loop adaptive optics (AO) systems. According to an analytical model and experimental results ob...

We demonstrate a simple method for mapping optical aberrations with 3D resolution within thick samples. The method relies on the local measurement of the variation in image quality with externally applied aberrations. We discuss the accuracy of the method as a function of the signal strength and of the aberration amplitude and we derive the achievable resolution for the resulting measurements. ...

PURPOSE To assess the repeatability of corneal wavefront aberrations derived from Pentacam (Oculus) corneal topography. SETTING Flinders Eye Centre, Flinders Medical Centre, Bedford Park, South Australia, Australia. METHODS Forty-five normal participants and 10 participants with keratoconus were tested. Intraobserver and interobserver repeatability was determined using 4 observers within an...

PURPOSE To describe the treatment of highly aberrated eyes due to previous excimer laser surgery or trauma. METHODS Three eyes (three patients) with reduced visual quality due to previous decentration or corneal laceration (one eye) underwent topography-guided ablation using the CXIII excimer laser (NIDEK Co Ltd) to correct residual refractive error and/or wavefront aberrations. RESULTS Pos...

PURPOSE To evaluate the repeatability of wavefront measurements using the NIDEK OPD-Scan. METHODS A total of 179 eyes from 90 healthy volunteers (57 women and 33 men) with no corneal or lenticular pathology and normal visual acuity were enrolled in this study. Mean patient age was 39 years (range: 17 to 85 years). All patients underwent four consecutive measurements by one examiner with the N...