Results 301 to 310 of about 643,248 (351)

Spherical aberrations of multipoles

Journal of Applied Physics, 1987
It is demonstrated in this article that for an electromagnetic 2n−pole system with n=odd, the only existing symmetric aberration which could be used to correct the spherical aberrations of a round lens is the order of 2n−3. Thus, a 2n−pole corrector can only be used to cancel the aberration of round lenses of order 2n−3.
Zhifeng Shao, A. V. Crewe
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Corneal Asphericity and Spherical Aberration

Journal of Refractive Surgery, 2007
ABSTRACT PURPOSE: To summarize the various values of asphericity in different notations and present how corneal asphericity, corneal curvature, and entrance pupil diameter influence the longitudinal spherical aberration of the anterior corneal surface. METHODS: After the conversion factors between the different asphericity notations
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Spherical aberration in contact lens wear

Contact Lens and Anterior Eye, 2008
The aim of the present studies was to investigate the effect on spherical aberration of different non custom-made contact lenses, both with and without aberration control.A wavefront analyser (Zywave, Bausch & Lomb) was used to measure the aberrations in each subject's right eye uncorrected and with the different contact lenses.
A, Lindskoog Pettersson, C, Jarkö, A, Alvin, P, Unsbo, R, Brautaset   +4 more
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Spherical Aberrations of Human Astigmatic Corneas

Journal of Refractive Surgery, 2011
Purpose: To evaluate whether the average spherical aberration of human astigmatic corneas is statistically equivalent to human nonastigmatic corneas. Methods: Spherical aberrations of 445 astigmatic corneas prior to laser vision correction were retrospectively ...
Huawei, Zhao, Guang-Ming, Dai, Li, Chen, Henk A, Weeber, Patricia A, Piers   +4 more
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Spherical gradient-index polymer lens with low spherical aberration

Applied Optics, 1994
A sphere lens with a spherical gradient index (GRIN) was prepared by the modified suspension polymerization technique. GRIN spheres with quadratic- and linear-index distributions were obtained by two different methods to confirm the effect of the GRIN profile on the focusing property of the sphere lens.
Y, Koike, A, Kanemitsu, Y, Shioda, E, Nihei, Y, Ohtsuka   +4 more
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Spherical aberration reduction in nuclear cataracts

Graefe's Archive for Clinical and Experimental Ophthalmology, 2016
To measure higher-order aberrations (HOAs) in nuclear cataracts and to investigate spherical aberration changes with nuclear cataract progression.A total of 102 eyes of older subjects (>50 years) were classified based on the nuclear opalescence (NO) grading of the Lens Opacities Classification System III: Group 1 (< NO2, 35), 2 (NO2, 23), 3 (NO3, 23 ...
Jong-Hyuck, Lee, Hun Gu, Choo, Sun Woong, Kim   +2 more
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Spherical aberration gauge for human vision

Applied Optics, 2010
Spherical aberration affects vision in varying degrees depending on pupil size, accommodation, individual eye characteristics, and interpretations by the brain. We developed a spherical aberration gauge to help evaluate the correction potential of spherical aberration in human vision.
Bruce M, Pixton, John E, Greivenkamp
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Spherical aberration of the crystalline lens

Vision Research, 1983
Split beams of varying separations from a helium-neon laser were directed through the crystalline lenses of a number of vertebrates. Photographs of the focal effects indicate the extent to which the refractive index variation of the lens and lens shape control spherical aberration.
J G, Sivak, R O, Kreuzer
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Predictability of ocular spherical aberration after cataract surgery determined using preoperative corneal spherical aberration

Journal of Cataract and Refractive Surgery, 2010
To evaluate the predictability of total postoperative spherical aberration after aspheric intraocular lens (IOL) implantation using preoperative corneal spherical aberration.Keio University Hospital, Tokyo, Japan.Corneal and ocular higher-order aberrations (HOAs) were analyzed preoperatively and postoperatively in eyes having cataract extraction with ...
Kazuno, Negishi, Chiyo, Kodama, Takefumi, Yamaguchi, Hidemasa, Torii, Megumi, Saiki, Murat, Dogru, Kazuhiko, Ohnuma, Kazuo, Tsubota   +7 more
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Adaptive aberration correction for specimen induced spherical aberration

Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170), 2001
Summary form only given. In normal operation with a dry or oil immersion microscope objective there is an index mismatch with a water-based biological sample. This index mismatch causes a depth dependant spherical aberration that severely limits the range that a sample can be imaged along the optical axis.
L. Sherman, J.Y. Ye, T.B. Norris
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