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.

Retinal image quality in the rodent eye

1998 ◽  
Vol 15 (4) ◽  
pp. 597-605 ◽  
Author(s):  
PABLO ARTAL ◽  
PILAR HERREROS de TEJADA ◽  
CARMEN MUÑOZ TEDÓ ◽  
DANIEL G. GREEN
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Ccd Camera ◽  
Retinal Images ◽  
Modulation Transfer ◽  
Double Pass ◽  
Human Eye ◽  
Sensitivity Functions ◽  
Upper Limit ◽  
Rats And Mice

Many rodents do not see well. For a target to be resolved by a rat or a mouse, it must subtend a visual angle of a degree or more. It is commonly assumed that this poor spatial resolving capacity is due to neural rather than optical limitations, but the quality of the retinal image has not been well characterized in these animals. We have modified a double-pass apparatus, initially designed for the human eye, so it could be used with rodents to measure the modulation transfer function (MTF) of the eye's optics. That is, the double-pass retinal image of a monochromatic (λ = 632.8 nm) point source was digitized with a CCD camera. From these double-pass measurements, the single-pass MTF was computed under a variety of conditions of focus and with different pupil sizes. Even with the eye in best focus, the image quality in both rats and mice is exceedingly poor. With a 1-mm pupil, for example, the MTF in the rat had an upper limit of about 2.5 cycles/deg, rather than the 28 cycles/deg one would obtain if the eye were a diffraction-limited system. These images are about 10 times worse than the comparable retinal images in the human eye. Using our measurements of the optics and the published behavioral and electrophysiological contrast sensitivity functions (CSFs) of rats, we have calculated the CSF that the rat would have if it had perfect rather than poor optics. We find, interestingly, that diffraction-limited optics would produce only slight improvement overall. That is, in spite of retinal images which are of very low quality, the upper limit of visual resolution in rodents is neurally determined. Rats and mice seem to have eyes in which the optics and retina/brain are well matched.

scholarly journals In vivo optical quality of posterior-chamber phakic implantable collamer lenses with a central port

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Robert Montés-Micó ◽  
Francisco Pastor-Pascual ◽  
Enrique Artiaga-Elordi ◽  
Ramón Ruiz-Mesa ◽  
Pedro Tañá-Rivero
Keyword(s):  
Quality Measurement ◽  
Optical Quality ◽  
Posterior Chamber ◽  
Optical Parameters ◽  
Modulation Transfer ◽  
Implantable Collamer Lens ◽  
Icl V4c

Abstract Background The aim of this review is to summarize the optical quality results in patients following the implantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc.). Main text A literature search in several databases was carried out to identify those publications, both prospective, retrospective and/or comparative with other refractive surgery procedures, reporting optical outcomes of patients who were implanted with the V4c ICL model. A total of 17 clinical studies published between 2012 and 2021 were included in this review. A detailed analysis of the available data was performed including number of eyes, follow-up and preoperative spherical equivalent. Specifically, the review focused on several optical parameters including higher-order aberrations (HOAs), modulation transfer function (MTF) cut-off frequency and Strehl ratio. This review encompassed a total of 817 eyes measured using different optical devices based on Hartmann-Shack, retinal image quality measurement and ray-tracing technologies at different follow-ups. Conclusions The outcomes found in this review lead us to conclude that the ICL V4c model provides good optical quality, by means of different metrics, when implanted.

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.

Aberrations and retinal image quality of the normal human eye

1997 ◽  
Vol 14 (11) ◽  
pp. 2873 ◽  
Author(s):  
Junzhong Liang ◽  
David R. Williams
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Human Eye ◽  
Normal Human

Odd aberrations and double-pass measurements of retinal image quality

1995 ◽  
Vol 12 (2) ◽  
pp. 195 ◽  
Author(s):  
Pablo Artal ◽  
Susana Marcos ◽  
David R. Williams ◽  
Rafael Navarro
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Double Pass
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