scholarly journals Aberration-Based Quality Metrics in Holographic Lenses

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 993 ◽  
Author(s):  
Tomás Lloret ◽  
Víctor Navarro-Fuster ◽  
Manuel G. Ramírez ◽  
Marta Morales-Vidal ◽  
Augusto Beléndez ◽  
...  
Keyword(s):  
Modulation Transfer Function ◽  
Cutoff Frequency ◽  
Optical Quality ◽  
Wavefront Sensor ◽  
Mean Square ◽  
Modulation Transfer ◽  
Symmetrical Configuration ◽  
Good Agreement ◽  
Seidel Coefficients

Aberrations and the image quality of holographic lenses were evaluated by a Hartmann–Shack (HS) wavefront sensor. Two lenses, one recorded with a symmetrical configuration and the other with an asymmetrical one, were stored in a photopolymer called Biophotopol. Each was reconstructed with two different wavelengths, 473 nm and 633 nm. Different metrics were applied to determine and quantify the aberration of the lenses (Zernike coefficients, Seidel coefficients, Marechal tolerances, root-mean-square (RMS), peak to valley, critical fraction of the pupil), and the quality of the image they provided (Strehl ratio, entropy, cutoff frequency, modulation transfer function (MTF), and area under the MTF). Good agreement between the metrics related to optical quality was obtained. The negative asymmetric holographic lenses had less aberration than the positive symmetric ones.

scholarly journals Optical tolerance to rotation of trifocal toric intraocular lenses as a function of the cylinder power

2020 ◽  
pp. 112067212092684
Author(s):  
Javier Ruiz-Alcocer ◽  
Amalia Lorente-Velázquez ◽  
Pablo de Gracia ◽  
David Madrid-Costa
Keyword(s):  
Transfer Function ◽  
Intraocular Lens ◽  
Modulation Transfer Function ◽  
Optical Quality ◽  
Significant Loss ◽  
Intraocular Lenses ◽  
Modulation Transfer ◽  
The Impact ◽  
Distance Vision

Background: The aim was to assess the impact of 5- and 10-degree rotations in the optical quality of a trifocal toric intraocular lens with different amounts of cylinder. Methods: Two Physiol Toric intraocular lenses with 1.5 and 3.0 D of cylinder were analysed in three different positions: centred, 5 and 10 degrees rotated. The optical quality of the intraocular lenses was evaluated with the PMTF optical bench through specific perpendicular targets. The analysis was performed by the through-focus modulation transfer function curves and the modulation transfer function corresponding to distance vision (0 D of vergence). Results: For a centred situation, the through-focus modulation transfer function curves of both intraocular lenses showed the classical three peaks corresponding to the powers of the two principal meridians of the intraocular lenses. When 5 and 10 degrees of rotation were induced, the three peaks were attenuated in both cases. The case with the intraocular lens with 3.0 D of cylinder and 10 degrees of rotation showed the worst optical quality and a significant loss of trifocality. The modulation transfer function values obtained for distance vision also showed the worst optical quality for the intraocular lens with 3.0 D of cylinder and 10 degrees of rotation. Conclusion: Rotations over 5 degrees decreased the optical quality of trifocal toric intraocular lenses, being this reduction moderate from 5 to 10 degrees for low levels of cylinder (≤1.5 D). For mid-high levels of cylinder (≥3.0 D), rotations over 5 degrees cause a significant loss of optical quality at all object distances.

scholarly journals Assessing the in vitro optical quality of presbyopic solutions based on the axial modulation transfer function

2016 ◽  
Vol 42 (5) ◽  
pp. 780-787 ◽  
Author(s):  
Eleni Papadatou ◽  
Antonio J. Del Águila-Carrasco ◽  
José J. Esteve-Taboada ◽  
David Madrid-Costa ◽  
Robert Montés-Micó
Keyword(s):  
Transfer Function ◽  
Modulation Transfer Function ◽  
Optical Quality ◽  
Modulation Transfer

scholarly journals Correlation between polychromatic image quality metrics to predict visual acuity in pseudophakic patients

2020 ◽  
Vol 238 ◽  
pp. 12005
Author(s):  
Jesús Armengol ◽  
Nuria Garzón ◽  
Fidel Vega ◽  
Irene Altemir ◽  
María S. Millán
Keyword(s):  
Visual Acuity ◽  
Modulation Transfer Function ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Modulation Transfer ◽  
Multifocal Intraocular Lenses ◽  
Mathematical Expressions ◽  
High Linear Correlation

The optical quality of three multifocal intraocular lenses (MIOLs) was measured in vitro using the area under the modulation transfer function (MTFa) and energy efficiency (EE). We evaluated those metrics through-focus (TF) by axially scanning the image space with three wavelengths (R, G, B). High linear correlation between MTFa and EE was found for all cases. Correlations between optical in vitro results (polychromatic TF-MTFa and TF-EE) and clinical visual acuity (VA) defocus curves for the three MIOLs allowed us to derive mathematical expressions. Both metrics proved to be equivalent to predict postoperative VA.

Effect of defocus combined with rotation on the optical performance of trifocal toric IOLs

2021 ◽  
pp. 112067212110021
Author(s):  
Javier Ruiz-Alcocer ◽  
Irene Martínez-Alberquilla ◽  
Amalia Lorente-Velázquez ◽  
José F Alfonso ◽  
David Madrid-Costa
Keyword(s):  
Visual Quality ◽  
Optical Quality ◽  
Refractive Errors ◽  
Focal Points ◽  
Modulation Transfer ◽  
Optical Analysis ◽  
Toric Intraocular Lens ◽  
Toric Iols ◽  
Reference Situation

Purpose: To objectively analyze the optical quality of the FineVision Toric intraocular lens (IOL) with two cylinder powers when different combinations of rotations and residual refractive errors are induced. Methods: This study assessed the FineVision Toric IOL with two different cylinder powers: 1.5 and 3.0 diopters (D). Three different rotation positions were considered: centered, 5° and 10° rotated. An optical bench (PMTF) was used for optical analysis. The optical quality of the IOLs was calculated by the modulation transfer function (MTF) at five different focal points (0.0, 0.25, 0.50, 0.75, and 1.00 D). Results: The MTF averaged value of the reference situation was 38.58 and 37.74 for 1.5 and 3.0 D of cylinder, respectively. For the 1.5 D cylinder, the combination of 5° of rotation with a defocus of 0.25, 0.50, 0.75, and 1.0 D induced a decrease on the MTF of 12.39, 19.94, 23.43, 24.23 units, respectively. When induced rotation was 10°, the MTF decrease was 17.26, 23.40, 24.33, 24.48 units, respectively. For the 3.0 D cylinder, the combination of 5° with 0.25, 0.50, 0.75, and 1.0 D of defocus, induced a decrease on the MTF of 12.51, 18.97, 22.36, 22.48 units, respectively. When induced rotation was 10°, the MTF decrease was: 18.42, 21.57, 23.08, and 23.61 units, respectively. Conclusion: For both FineVision Toric IOLs there is a certain optical tolerance to rotations up to 5° or residual refractive errors up to 0.25 D. Situations over these limits and their combination would affect the visual quality of patients implanted with these trifocal toric IOLs.

Influence of Progressive Lenses in the Retinal Image Quality

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 156-156
Author(s):  
J Gispets ◽  
M Arjona ◽  
J Pujol
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Human Subjects ◽  
Optical Quality ◽  
Optical Systems ◽  
Modulation Transfer ◽  
Double Pass ◽  
Progressive Lenses

Progressive lenses (PL) are widely used to correct presbyopia, a visual dysfunction that affects most of the population aged over 40 years. The methods used to evaluate the optical quality of these lenses are mainly based on ray-tracing and optical bench testing. Psychophysical studies based on measurements of the contrast sensitivity function of human subjects also exist. However, all these methods exhibit important limitations because, in general, they do not take into account the optics of the eye. One of the objective techniques that permits evaluation of the retinal image in-vivo is the double pass method (Santamaria et al, 1987 Journal of the Optical Society of America A4 1109 – 1114). It has been possible to study the retinal image quality for different correcting optical systems, such as contact lenses, with this technique (Torrents et al, 1996 Perception25 Supplement, 112 – 113). We studied the retinal image quality of the optical system formed by the eye and a progressive lens. The retinal image quality, characterised by the modulation transfer function (MTF), was measured for different observers as a variety of lines of sight that covered a lens diameter of 50 mm. We show the MTF variation as a function of the lens region and the capacity of this technique to characterise these optical systems.

scholarly journals Visual acuity and image quality in 5 diffractive intraocular lenses

2017 ◽  
Vol 28 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Genís Cardona ◽  
Fidel Vega ◽  
Miguel A. Gil ◽  
Consuelo Varón ◽  
José A. Buil ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Image Quality ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Modulation Transfer ◽  
Multifocal Intraocular Lenses ◽  
Corrected Distance Visual Acuity ◽  
Good For

Purpose: To compare objective image quality at distant, intermediate, and near foci with the corresponding visual acuity (VA) in patients symmetrically implanted with 5 different diffractive multifocal intraocular lenses (IOLs) (ReSTOR SV25T0, Tecnis ZKB00, Tecnis ZLB00, AT LISA 809, and AT LISA Tri 839MP) and a monofocal lens (Tecnis ZA9003) 3 months after cataract intervention. Methods: Objective image quality, measured as the area under the modulation transfer function curve (AMTF), was tested in vitro in an eye model. In addition, corrected distance visual acuity and distance-corrected intermediate and near visual acuities (DCIVA and DCNVA) were assessed in a group of 79 patients, randomly implanted with one of the lenses. Results: Image quality and VA at the distant focus was good for all lens designs, but was similarly compromised at the intermediate focus, where the best DCIVA corresponded to the low add ZKB00. At the near focus, the monofocal lens and the distance dominant SV25T0 had the worst AMTF values, with the ZLB00 presenting the best DCNVA. The relationship between AMTF and VA was found not to be linear, with VA being similarly good for AMTF values over a certain threshold. Conclusions: Visual acuity of pseudophakic patients reflected the optical quality of the specific IOL design within a certain range of measurements, beyond which maximum VA is limited by other ocular, optical, and neuropsychophysical factors.

scholarly journals PENINGKATAN KUALITAS FOKUS CITRA IMAGER MULTISPEKTRAL SATELIT LAPAN-A3 (IMAGE-FOCUSING QUALITY IMPROVEMENT ON LAPAN-A3 SATELLITE MULTISPECTRAL IMAGER)

2018 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Andi Mukhtar Tahir ◽  
Patria Rachman Hakim ◽  
A. Hadi Syafruddin
Keyword(s):  
Image Quality ◽  
Transfer Function ◽  
Modulation Transfer Function ◽  
Near Infrared ◽  
Beam Splitter ◽  
Modulation Transfer ◽  
Color Channel ◽  
Multispectral Imager ◽  
Image Focus

LAPAN-A3 satellite brings a multispectral imager as main payload which has four color channel, i.e.: red, green, blue and near-infrared. The imager optics system uses beam-splitter mechanism, which divides the incoming light passing lens system into each color channel detector. Since each channel detector has different position and orientation with respect to lens center, then images produced by each channel detector will have different image focus quality. Such factor could reduce the quality of image produced. This research aims to improve the composite image quality of LAPAN-A3 satellite multispectral imager by ensuring that every channel detector will have uniform focus setting. The method used in this research consists of taking series of observation of object with zebra-cross pattern, then processed them by using Imatest software. The determination of the quality of each image focus are based on Modulation Transfer Function (MTF) calculation in particular spatial frequency. After several observations and calculation, image focus level of each channel detector can be successfully uniformed by controlling the distance of each detector to the center of lens. Furthermore, the experiment also able to reduce distortion caused by channel co-registration in horizontal axes. As a result, image quality of LAPAN-A3 satellite multispectral imager can be improved significantly. These results can be used as reference on the actual LAPAN-A3 sattelite ground station operation, and to support the development of experimental multispectral imager that is prepared for the next LAPAN-A4 sattelite. ABSTRAKSatelit LAPAN-A3 membawa imager multispektral sebagai muatan utama, yang memiliki empat kanal warna yaitu merah, hijau, biru, dan near-infrared. Sistem optik imager dirancang dengan menggunakan beam-splitter yang akan membagi cahaya yang melewati sistem lensa menuju detektor masing-masing kanal warna. Karena setiap detektor memiliki posisi dan juga orientasi yang berbeda terhadap pusat lensa, maka akan terjadi ketidakseragaman derajat kefokusan untuk setiap citra yang dihasilkan oleh masing-masing kanal warna, yang dapat mengurangi kualitas citra komposit yang dihasilkan. Penelitian ini bertujuan untuk meningkatkan kualitas citra komposit imager multispektral satelit LAPAN-A3 dengan cara memastikan agar setiap kanal warna akan menghasilkan citra dengan derajat kefokusan yang seragam. Metode yang digunakan yaitu dengan mengambil sejumlah data pengamatan terhadap obyek dengan pola geometri zebra-cross, dan kemudian diolah dengan menggunakan perangkat lunak Imatest. Penentuan kualitas fokus citra dilakukan dengan mengukur Modulation Transfer Function (MTF) pada frekuensi spasial tertentu. Berdasarkan sejumlah pengamatan dan perhitungan yang dilakukan, derajat kefokusan citra yang dihasilkan masing-masing detektor dapat diseragamkan dengan mengatur jarak detektor tersebut terhadap pusat lensa. Selain itu, percobaan yang dilakukan juga dapat mengurangi distorsi ko-registrasi kanal yang terjadi pada sumbu horisontal. Kedua hasil tersebut secara signifikan dapat meningkatkan kualitas citra imager multispektral satelit LAPAN-A3, terutama dalam aspek geometri. Hasil penelitian ini diharapkan dapat digunakan sebagai panduan dalam proses operasional satelit LAPAN-A3 selanjutnya dan juga dapat mendukung pengembangan imager multispektral eksperimen yang sedang dikembangkan untuk satelit LAPAN-A4.

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