NIMO: a new tool for asphere and free-form optics measurement

Joannes, Luc; Heraud, M. M.; Ligot, Renaud; Saoul, Bruno; Dupont, Olivier

doi:10.1117/12.696006

Cited by 3 publications

(3 citation statements)

References 5 publications

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“…This technique combines the Schlieren principle with the phase-shifting technique that is used in interferometry by using a Schlieren lter and an adapted set-up. After the application of the phase shift technique, the Schlieren phase was calculated and converted into beam deviation values 17 .…”

Section: Measurements Of the Optical Pro Le Of Contact Lensesmentioning

confidence: 99%

“…in multifocal solutions two continuous zones can be discontinuous and present radically different sagittal powers that cannot be represented with a single set of Zernike polynomials). This is one of the major reasons for the lack of a procedure to derive an optical quality metric from optical pro les produced by optical metrology instruments such as NIMO 17 .…”

Section: Introductionmentioning

confidence: 99%

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Fourier Tools for the Evaluation of Refractive Multifocal Designs

Gracia

2023

Preprint

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Tools and methods for the theoretical evaluation of optical properties of refractive multifocal commercial designs are presented, which use segmentation techniques to divide the pupil and classical Fourier optics. They can be applied to refractive designs such as multifocal contact lenses and intraocular lenses as well as to the study of small aperture designs and corneal inlays. In this paper, the optical profiles of 12 multifocal, commercially available, contact lenses from four companies were measured with the help of the NIMO equipment (LAMBDA-X). The corresponding through-focus Visual Strehl ratios were computed in the frequency domain to quantify image quality as a single scalar value. The multifocal properties of each of the commercial contact lenses were evaluated for three different base prescriptions (-6.00 D, -3.00 D, and + 1.00 D) in 65 patients. The contact lenses of this study were also evaluated in conjunction with the higher-order aberrations obtained from 65 eyes collected by using a standard Shack-Hartmann sensor. The diameters used for the evaluation of the contact lenses varied according to each eye’s pupil size (from 2.45 to 6.27 mm). The proposed tools have allowed us to evaluate multifocal solutions in a theoretical manner without the necessity of creating prototypes. They helped us differentiate between lenses created for young and old presbyopes, instructed the proper utilization of hyperfocal distance in the field of contact lens design, and demonstrated the importance of the effective aperture effect. This is the first proposed method that converts sagittal powers of multifocal solutions into their equivalent optical quality metric. It can be applied to the evaluation of myopia control methods. It is the author’s hope that the reader appreciates the tools presented and uses them to further the field of refractive multifocality.

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Section: Measurements Of the Optical Pro Le Of Contact Lensesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fourier Tools for the Evaluation of Refractive Multifocal Designs

Gracia

2023

Preprint

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“…18 There are other means of measuring the deflection of rays by the test surface or in transmission by a lens under test, e.g., phase shifting Schlieren. 19 All deflectometric measurement approaches have in common that they are sensitive to gradients and thus excel in the detection of high-frequency surface defects even down to a height of a few nanometers. But for global shape measurements, due to the integration step involved, the absolute curvature and low-frequency surface errors tend to be detected with a lower accuracy, which is a disadvantage compared to height measuring methods such as interferometry.…”

Section: Testing Of Aspheres and Freeform Lensesmentioning

confidence: 99%

Measuring aspheres quickly: tilted wave interferometry

Pruß

Baer²,

Schindler

2017

Opt. Eng

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Abstract. Functional surfaces with a rising degree of complexity are becoming increasingly important for modern industrial products. It is common knowledge that one cannot produce surfaces better than it is possible to measure them. Consequently, the demand for their effective and precise measurement has increased to the same extent as their production capabilities have grown. Important classes of optical functional surfaces are aspheres and freeforms. Both types of surfaces have become essential parts of modern optical systems such as laser focusing heads, sensors, telescopes, glasses, head-mounted displays, cameras, lithography steppers, and pickup heads. For all of them, the systematic quality control in the process of their fabrication is essential. We review the challenges of asphere and freeform testing and how available metrology systems cope with it. A special focus is on tilted wave interferometry and how it compares to other methods. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Fourier tools for the evaluation of refractive multifocal designs

De Gracia

2023

Sci Rep

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This paper presents innovative tools and methodologies for the theoretical assessment of optical properties in refractive multifocal designs. Utilizing lens segmentation techniques and classical Fourier optics, these tools can be of help evaluating multifocal contact lenses, intraocular lenses, small aperture designs, and corneal inlays. As an example of their utility, this study presents the through-focus Visual Strehl ratios in the frequency domain of 12 multifocal contact lenses from four companies, derived from the sagittal power profiles obtained with a NIMO equipment (LAMBDA-X) for three base prescriptions (− 6.00 D, − 3.00 D, and + 1.00 D). The contact lenses are also assessed alongside higher-order aberrations obtained from 65 eyes, measured using a Wavefront Sciences Complete Ophthalmic Analysis System (AMO). Diameter variations, corresponding to individual pupil sizes (2.45–6.27 mm), were considered in the evaluation. These novel tools enable the theoretical evaluation of multifocal solutions without the need for prototypes. In the case examples presented, they differentiate between lenses tailored for different presbyopic age groups, offer guidance on optimizing hyperfocal distance in contact lens design, and underscore the relevance of the effective aperture effect. Notably, this paper introduces the pioneering conversion of sagittal powers of multifocal solutions into an equivalent wavefront and optical quality metric, with potential applications in myopia control assessments. The author hopes that readers recognize and utilize these tools to advance the field of refractive multifocality.

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NIMO: a new tool for asphere and free-form optics measurement

Cited by 3 publications

References 5 publications

Fourier Tools for the Evaluation of Refractive Multifocal Designs

Fourier Tools for the Evaluation of Refractive Multifocal Designs

Measuring aspheres quickly: tilted wave interferometry

Fourier tools for the evaluation of refractive multifocal designs

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