As an extension of the knife-edge test, a noninterferometric method for inspecting circularly symmetric aspheres is proposed in which the test surface is illuminated by a spherical wave. When a small circular stop is placed around the curvature center of the best-fitting sphere, only rays characteristic for the deviation from a perfect sphere remain unobstructed. An image of the tested surface is thereby obtained, showing light and dark regions whose boundaries are correlated to the surface profile, the stop size, and the stop position along the symmetry axis. The experiment has been carried out with a paraboloid.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/ao.37.005969 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Can fundus features tell us something about 3D eye shape?
Ophthalmic Physiol Opt
January 2025
Robert O Curle Ophthalmology Suite, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh, UK.
Purpose: To determine whether imaging features derived from fundus photographs contain 3D eye shape information beyond that available from spherical equivalent refraction (SER).
Methods: We analysed 99 eyes of 68 normal adults in the UK Biobank. An ellipsoid was fitted to the entire volume of each posterior eye (vitreous chamber without the lens)-segmented from magnetic resonance imaging of the brain.
Comparison of two-year myopia control efficacy between spectacle lenses with highly aspherical lenslets and orthokeratology lenses.
Cont Lens Anterior Eye
January 2025
State Key Laboratory of Ophthalmology, Optometry and Vision Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China; National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital Wenzhou Medical University, Wenzhou, China. Electronic address:
Purpose: To compare the two-year efficacy of spectacle lenses with highly aspherical lenslets (HAL) and orthokeratology (OK) lenses in managing myopia in children.
Methods: This retrospective study examined medical records from the Affiliated Eye Hospital of Wenzhou Medical University, involving 1683 HAL users and 1192 OK users. Participants were children aged 8-13 with a refractive error of -0.
Advances in Corneal Diagnostics Using Machine Learning.
Bioengineering (Basel)
November 2024
Department of Electrical & Electronic Engineering, College of Engineering, Universiti Tenaga Nasional, Kajang 43000, Malaysia.
This paper provides comprehensive insights into the cornea and its diseases, with a particular focus on keratoconus. This paper explores the cornea's function in maintaining ocular health, detailing its anatomy, pathological conditions, and the latest developments in diagnostic techniques. Keratoconus is discussed extensively, covering its subtypes, etiology, clinical manifestations, and the application of the Q-value for quantification.
View Article and Find Full Text PDFAspherical Surface Wavefront Testing Based on Multi-Directional Orthogonal Lateral Shearing Interferometry.
Sensors (Basel)
December 2024
School of Opto-Electronics Engineering, Xi'an Technological University, Xi'an 710021, China.
To overcome the limitations of phase sampling points in testing aspherical surface wavefronts using traditional interferometers, we propose a high-spatial-resolution method based on multi-directional orthogonal lateral shearing interferometry. In this study, we provide a detailed description of the methodology, which includes the theoretical foundations and experimental setup, along with the results from simulations and experiments. By establishing a relational model between the multi-directional differential wavefront and differential Zernike polynomials, we demonstrate high-spatial-resolution wavefront reconstruction using multi-directional orthogonal lateral shearing interferometry.
View Article and Find Full Text PDFExtremely high accuracy is demanded for optics working at very short wavelength. Interferometric testing of optical aspheres or freeform surfaces requires null optics, typically computer-generated holograms (CGHs), to balance the wave aberrations. The measurement uncertainty is primarily limited by the accuracy of the test wavefront, which is predominantly influenced by the CGH and the interferometer optics.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!