نتایج جستجو برای: aberrations

تعداد نتایج: 17220  

Journal: :Journal of vision 2010
Lucie Sawides Enrique Gambra Daniel Pascual Carlos Dorronsoro Susana Marcos

We measured the effect of the correction of the natural aberrations of the eye by means of adaptive optics on the subject's performance on three different visual tasks: subjective sharpness assessment of natural images, familiar face recognition, and facial expression recognition. Images were presented through a dedicated psychophysical channel and viewed through an electromagnetic deformable m...

Journal: :Bulletin de la Societe belge d'ophtalmologie 2006
S Marcos

This paper addresses the concept, measurement and applications of wave aberrations. The ocular optics is not perfect. Apart from conventional low order aberrations (such as defocus and astigmatism) retinal images are degraded by other high order aberrations. Aberrometers typically measure ray deviations at the retinal plane, as a function of pupil position, i.e. local derivatives of the wave ab...

Journal: :Haematologica 2011
Rebeqa Gunnarsson Larry Mansouri Anders Isaksson Hanna Göransson Nicola Cahill Mattias Jansson Markus Rasmussen Jeanette Lundin Stefan Norin Anne Mette Buhl Karin Ekström Smedby Henrik Hjalgrim Karin Karlsson Jesper Jurlander Christian Geisler Gunnar Juliusson Richard Rosenquist

BACKGROUND High-resolution genomic microarrays enable simultaneous detection of copy-number aberrations such as the known recurrent aberrations in chronic lymphocytic leukemia [del(11q), del(13q), del(17p) and trisomy 12], and copy-number neutral loss of heterozygosity. Moreover, comparison of genomic profiles from sequential patients' samples allows detection of clonal evolution. DESIGN AND ...

Journal: :Investigative ophthalmology & visual science 2017
Achim Fieß Alexander K Schuster Ruth Kölb-Keerl Markus Knuf Bernd Kirchhof Philipp S Muether Jacqueline Bauer

Purpose To compare corneal aberrations in former preterm infants to that of full-term infants. Methods A prospective cross-sectional study was carried out measuring the corneal shape with Scheimpflug imaging in former preterm infants of gestational age (GA) ≤32 weeks and full-term infants with GA ≥37 weeks now being aged between 4 to 10 years. The main outcome measures were corneal aberration...

2009
Ľudovít Mušák Erika Halašová Tatiana Matáková Lucia Letková Ludmila Vodičková Janka Buchancová Henrieta Hudečková Oto Osina Pavel Souček Pavel Vodička

Authors compared the incidence of chromosomal aberrations (CAs) of workers occupationally exposed to cytostatics (group EXP1) or anaesthetics (group EXP2) in relationship to polymorphism of GSTM1, GSTP1 and GSTT1 genes. The cytogenetic analysis for chromosomal aberrations frequency and for polymorphisms of genes the PCR and PCR-RFLP method were used. Statistically higher frequency of total CAs ...

Journal: :Investigative ophthalmology & visual science 2005
Robert Montés-Micó Jorge L Alió W Neil Charman

PURPOSE To examine the dynamics of the tear film in patients with dry eye by measuring the wavefront aberrations of the anterior surface of the film. METHODS Anterior surface aberrations for a 7-mm pupil were determined in 13 patients with dry eye at 1-second time intervals, for 15 seconds after a blink. The aberrations were calculated from the elevations provided by corneal topography. All d...

Journal: :Vision Research 2007
Ramkumar Ramamirtham Chea-su Kee Li-Fang Hung Ying Qiao-Grider Juan Huang Austin Roorda Earl L. Smith

The purpose of this study was to investigate the relationship between refractive errors and high-order aberrations in infant rhesus monkeys. Specifically, we compared the monochromatic wave aberrations measured with a Shack-Hartman wavefront sensor between normal monkeys and monkeys with vision-induced refractive errors. Shortly after birth, both normal monkeys and treated monkeys reared with o...

Journal: :Head & neck 2007
Bernhard Schick Silke Wemmert Ulrike Bechtel Piero Nicolai Thiemo Hofmann Wieslaw Golabek Steffi Urbschat

BACKGROUND Frequent beta-catenin mutations have been detected in juvenile angiofibromas, but the tumor pathogenesis remains unknown. METHODS Metaphase-comparative genomic hybridization (CGH) was used to identify chromosomal aberrations in 29 tumor specimens. Two tumors were investigated using genome DNA microarrays. RESULTS Three hundred eleven chromosomal gains and losses were detected by ...

2005
C. Cavarroc A. Boccaletti P. Baudoz T. Fusco D. Rouan

We analyse the fundamental limitations for the detection of extraterrestrial planets with Extremely Large Telescopes. For this task, a coronagraphic device combined to a very high order wavefront correction system is required but not sufficient to achieve the 10 −10 contrast level needed for detecting an Earth-like planet. The stellar residuals left uncorrected by the wavefront correction syste...

Journal: :Journal of the Optical Society of America. A, Optics, image science, and vision 2002
Geun-Young Yoon David R Williams

The development of technology to measure and correct the eye's higher-order aberrations, i.e., those beyond defocus and astigmatism, raises the issue of how much visual benefit can be obtained by providing such correction. We demonstrate improvements in contrast sensitivity and visual acuity in white light and in monochromatic light when adaptive optics corrects the eye's higher-order monochrom...

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