Results 81 to 90 of about 43,714 (202)

Simultaneously measuring ocular aberration and anterior segment biometry during accommodation [PDF]

Journal of Innovative Optical Health Sciences, 2015
In the human eye, accommodation is essential for functional vision. However, the mechanisms regulating accommodation and the ocular parameters affecting aberrations remain to be explored.
Yuanyuan Wang, Yilei Shao, Yimin Yuan
doaj   +1 more source

Reaching the fundamental sensitivity limit of wavefront sensing on arbitrary apertures with the Phase Induced Amplitude Apodized Zernike Wavefront Sensor (PIAA-ZWFS) [PDF]

arXiv, 2023
In the last two decades many people have been searching for the optimal wavefront sensor as it can boost the performance of high-contrast imagining by orders of magnitude on the ELTs. According classical information theory, the optimal sensitivity of a wavefront sensor is 1/2 radian rms per photon.
arxiv  

Soft X‐ray wavefront sensing at an ellipsoidal mirror shell

Journal of Synchrotron Radiation, Volume 31, Issue 4, Page 690-697, July 2024.
Phase retrieval at an axisymmetric ellipsoidal mirror is demonstrated with soft X‐rays (277 eV), completed by a reconstruction of the focus as well as figure and alignment error of the mirror. Based on simple measurements of the cross‐focal, three‐dimensional intensity distribution, an intuitive algorithm is proposed which combines the advantages of ...
Christoph Braig, Jürgen Probst, Heike Löchel, Ladislav Pina, Thomas Krist, Christian Seifert   +5 more
wiley   +1 more source

A new low-cost, compact, auto-phoropter for refractive assessment in developing countries

Scientific Reports, 2017
Using a phoropter to measure the refractive error is one of the most commonly used methods by ophthalmologists and optometrists. Here, we demonstrate design and fabrication of a portable automatic phoropter with no need for patient’s feedback. The system
Babak Amirsolaimani, Gholam Peyman, Jim Schwiegerling, Arkady Bablumyan, N. Peyghambarian   +4 more
doaj   +1 more source

Gaze and behavioural metrics in the refractive correction of presbyopia

Ophthalmic and Physiological Optics, Volume 44, Issue 4, Page 774-786, June 2024.
Abstract Purpose To investigate gaze and behavioural metrics at different viewing distances with multifocal contact lenses (MFCLs), single vision contact lenses (SVCLs) and progressive addition lenses (PALs). Methods Fifteen presbyopic contact lens wearers participated over five separate study visits.
Sarah L. Smith, Carole Maldonado‐Codina, Philip B. Morgan, Michael L. Read   +3 more
wiley   +1 more source

Optimization Of Zonal Wavefront Estimation And Curvature Measurements [PDF]

, 2007
Optical testing in adverse environments, ophthalmology and applications where characterization by curvature is leveraged all have a common goal: accurately estimate wavefront shape.
Zou, Weiyao
core   +1 more source

Detection of significant vision conditions in children using QuickSee wavefront autorefractor

Ophthalmic and Physiological Optics, Volume 44, Issue 3, Page 501-513, May 2024.
Abstract Purpose This study evaluated the ability of QuickSee to detect children at risk for significant vision conditions (significant refractive error [RE], amblyopia and strabismus). Methods Non‐cycloplegic refraction (using QuickSee without and with +2 dioptre (D) fogging lenses) and unaided binocular near visual acuity (VA) were measured in 4‐ to ...
Anh Bui, G. Lynn Mitchell, Catherine McDaniel, Ann Morrison, Andrew Toole, Michelle Buckland, Marjean T. Kulp   +6 more
wiley   +1 more source

Ametropia detection using a novel, compact wavefront autorefractor

Ophthalmic and Physiological Optics, Volume 44, Issue 2, Page 311-320, March 2024.
Abstract Introduction Despite the well‐known reproducibility issues of subjective refraction, most studies evaluating autorefractors compared differences between the device and subjective refraction. This work evaluated the performance of a novel handheld Hartmann–Shack‐based autorefractor using an alternative protocol, which considered the inherent ...
Carlos S. Hernández, Andrea Gil, Amal Zaytouny, Ignacio Casares, Jesús Poderoso, Alfonso de Lara, Alec Wehse, Shivang R. Dave, Daryl Lim, Eduardo Lage, Nicolas Alejandre‐Alba   +10 more
wiley   +1 more source

Spectral characterization of optical aberrations in fluidic lenses

Frontiers in Physics
We report an extensive numerical study and supporting experimental results on the spectral characterization of optical aberrations in macroscopic fluidic lenses with tunable focal distance and aperture shape.
Graciana Puentes, Graciana Puentes, Fernando Minotti, Fernando Minotti   +3 more
doaj   +1 more source

Spectrally resolved single-shot wavefront sensing of broadband high-harmonic sources [PDF]

, 2017
Wavefront sensors are an important tool to characterize coherent beams of extreme ultraviolet radiation. However, conventional Hartmann-type sensors do not allow for independent wavefront characterization of different spectral components that may be present in a beam, which limits their applicability for intrinsically broadband high-harmonic generation
arxiv   +1 more source