Aberration correction in the TEM is now relatively well established with more than 20 corrected instruments installed worldwide. This paper will review these instrumental advances and will also describe the underlying theory and computation required to optimise data acquisition and interpret aberration corrected images. Finally the combination of direct electron optical correction and indirect ...

The resolution of conventional electron microscopes is usually limited by spherical aberration. Microscopes equipped with aberration correctors are then primarily limited by higher order, chromatic, and misalignment aberrations. In particular the Nion third-order aberration correctors installed on machines with a low energy spread and possessing sophisticated alignment software were limited by ...

Scanning confocal electron microscopy (SCEM) is a new imaging mode in electron microscopy. Spherical aberration corrected electron microscope instruments fitted with two aberration correctors can be used in this mode which provides improved depth resolution and selectivity compared to optical sectioning in a conventional scanning transmission geometry. In this article, we consider the depth res...

We derive equations for defocus and primary spherical wave aberration coefficients caused by a shift in image plane of a perfect optical system. The spherical aberration equation is accurate at describing changes in the spherical aberration of an aberrated schematic eye.

and Applied Analysis 3 operator, the chromatic aberration Canny operator was used instead to extract the coastline. (1) Calculation of the Chromatic Aberration Amplitude by Means of Chromatic Aberration Canny Operator. In order to improve on deficiencies of the traditional Canny operator, an improved Canny operator was used based on the LAB color model as the main technical route in this paper,...

As a single aperture, approximately monofocal optical system, the human eye generally creates a single image on the retina. However, the literature contains many reports of perceptual monocular diplopia. While it is easy to understand how distortion may produce monocular diplopia, its reported high incidence in normal eyes is less easily understood. We examine a model which ascribes monocular d...

The scaling of root mean square (RMS) wave aberration in an isometrically growing eye is investigated, along with changes due to measurements made at different relative pupil sizes. It is found that, relative to an initial state, if an eye expands in all directions by the factor k, and the wave aberration is then measured at a relative pupil size which has changed over the pupil size used for t...

The geometric theory of the aberration sensitivity of an unstable cavity to a spatially localized intracavity phase distortion is provided. Such a localized perturbation source could be caused by a small imperfection in some intracavity mirror (such as a deformable mirror) or by a turbulence zone in the flow field of a gas-laser gain medium. This geometric theory, first developed by Anan'ev [So...

PURPOSE Despite the proliferation of wavefront sensors to characterize the optical quality of individual eyes, there is not yet an accurate way to determine from a wave aberration how severely it will impact the patient's vision. Some of the most commonly used metrics, such as RMS wavefront error and the Strehl ratio, predict subjective image quality poorly. Our goal is to establish a better me...

purpose: to compare tecnis z9000 and acrysof iq aspheric intraocular lenses (iols) regarding spherical aberration and contrast sensitivity. methods: thirty-four eyes of 34 patients undergoing phacoemulsification cataract surgery were randomly assigned to implantation of tecnis or iq iols. three months postoperatively, best-corrected visual acuity (bcva), spherical aberration (with 4 and 6 mm pu...