The invention of spherical aberration correctors has been the most significant contribution to the field of transmission electron microscopy since the field emission gun. Chromatic and spherical aberration, well known from optics, also play a role in electron microscopy. Lens aberrations are not unique to the magnetic lenses used in electron microscopes, but rather a fundamental problem of opti...

The technological developments in the design of an adaptive optical scanning acoustic microscope are described. Its two key elements include a multi-channel acoustic wavefront detector to detect the acoustic wavefront aberration and a highly adaptive acoustic source to correct for the effects of aberration. We present experimental images acquired with the instrument that indicate the degree of ...

A contralateral bundle branch block (BBB) aberration during tachycardia with a preexisting BBB strongly suggests the presence of ventricular tachycardia. We report on a middle-aged, female patient presented with wide QRS tachycardia. The patient had orthodromic atrioventricular tachycardia with a left BBB aberration in the presence of a preexisting right BBB due to an abnormal His-Purkinje syst...

We read with interest the article by Esteve-Taboada et al.1 The authors measured the modulation transfer function (MTF) of three intraocular lenses (IOLs) using a corneal eye model with zero spherical aberration using monochromatic light. This means that corneal higher order aberrations and chromatic aberration were not taken into account for the evaluation, even though it has been shown that s...

If we talk about Stellar Aberration, then think of the form Aberration that was first discovered and explained by Bradley. In addition to Bradley's which can also be defined as Relative will define Absolute based on just one measurement. Here after refer $ASA$. We try explain in a few words why it is necessary measure interpret this way. Suppose performed two measurements Doppler Effect within ...

Advancements in cataract surgery and intraocular lens (IOL) design have optimized the postoperative optical performance of the pseudophakic eye. One of the recent spotlights of IOL design has been formulating optical properties similar to a clear, young lens and addressing spherical aberration. Spherical aberration in the human eye is a combination of the positive spherical aberration of the co...

PURPOSE To develop a prototype instrument that uses adaptive optics to introduce virtually any desired aberration profile in a subject's eye. At the same time, the instrument could be used to evaluate the subject's spatial vision for each controlled aberration profile. This "aberration testing station" or "visual simulator" allows us to study the relationship between specific aberrations and vi...

purpose: to determine the outcomes of visual correction with femto-lasik following pk. methods: in this prospective study, 34 eyes of 31 patient who had undergone thin – flap lasik due to high refractive error after corneal grafting were evaluated .after complete ocular examination and assessment of uncorrected and corrected distant visual acuity (ucva and bcva) , the patients underwent femto-l...

The expansion of wavefront-sensing techniques redefined the meaning of refractive error in clinical ophthalmology. Clinical aberrometers provide detailed measurements of the eye's wavefront aberration. The distribution and contribution of each higher-order aberration to the overall wavefront aberration in the individual eye can now be accurately determined and predicted. Using corneal or ocular...