Relevant bibliographies by topics / Accommodation of the lens

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Accommodation of the lens'

Author: Grafiati
Published: 4 June 2021
Last updated: 10 February 2022

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Journal articles on the topic "Accommodation of the lens"

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Li, Jin, Qi Chen, Zhibo Lin, Lin Leng, Fang Huang, and Ding Chen. "The Predictability of Preoperative Pilocarpine-Induced Lens Shift on the Outcomes of Accommodating Intraocular Lenses Implanted in Senile Cataract Patients." Journal of Ophthalmology 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/6127130.

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Purpose. To evaluate the predictability of lens shift induced by pilocarpine (LSPilo) on the outcomes of accommodating intraocular lens (Acc-IOL) implantation.Methods. Twenty-four eyes of 24 senile cataract patients who underwent phacoemulsification and Acc-IOL implantation were enrolled.LSPilowas evaluated with anterior segment optical coherence tomography (AS-OCT). At 3 months postoperatively, the best corrected distance visual acuities (BCDVA), distance-corrected near visual acuities (DCNVA), and subjective and objective accommodations were measured. IOL shifts under accommodation stimulus (IOLSAcc) were evaluated with AS-OCT.Results. The meanLSPilowas 112.29 ± 30.72 µm.LSPilowas not associated with any preoperative parameters. The meanIOLSAccwas 130.46 ± 42.71 µm. The mean subjective and objective accommodation were 1.54 ± 0.39 D and 1.27 ± 0.41 D, respectively. The mean postoperative BCDVA and DCNVA (log MAR value) were 0.22 ± 0.11 and 0.24 ± 0.12, respectively.LSPilopositively correlated withIOLSAcc(r=0.541;P=0.006), subjective accommodation (r=0.412;P=0.022), and objective accommodation (r=0.466;P=0.045), respectively.Conclusion.LSPilois an independent preoperative parameter associated with the postoperative Acc-IOL mobility and pseudophakic accommodation. It may offer valuable information for ophthalmologists in determining the suitable candidates for Acc-IOL implantation.
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Zhang, Wen-Wen, and Zheng-Gao Xie. "Advances in the Study of Lens Refilling." Journal of Ophthalmology 2020 (August 26, 2020): 1–10. http://dx.doi.org/10.1155/2020/8956275.

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The ultimate goal of cataract surgery is to restore the accommodation while restoring distance visual acuity. Different kinds of accommodative intraocular lens (IOLs) and surgical techniques have been suggested to apply during the surgery, but they showed poor postoperative accommodation. It is possible to achieve this goal by refilling the lens with an injectable polymer. We present a summary of the existing materials, methods, results, and some obstacles in clinical application that remain of lens refilling for restoration of accommodation. Two main problems have restricted the clinical application of this technique. One was the formation of postoperative secondary capsule opacification and the other was the different accommodative power after surgery.
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Gibson, George, Fiona Cruickshank, James Wolffsohn, and Leon Davies. "Optical Coherence Tomography Reveals Sigmoidal Crystalline Lens Changes during Accommodation." Vision 2, no. 3 (August 21, 2018): 33. http://dx.doi.org/10.3390/vision2030033.

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This study aimed to quantify biometric modifications of the anterior segment (AS) during accommodation and to compare them against changes in both accommodative demand and response. Thirty adults, aged 18–25 years were rendered functionally emmetropic with contact lenses. AS optical coherence tomography (AS-OCT) images were captured along the 180° meridian (Visante, Zeiss Meditec, Jena, Germany) under stimulated accommodative demands (0–4 D). Images were analysed and lens thickness (LT) was measured, applying a refractive index correction of 1.00. Accommodative responses were also measured sequentially through a Badal optical system fitted to an autorefractor (Shin Nippon NVision-K 5001, Rexxam, Japan). Data were compared with Dubbelman schematic eye calculations. Significant changes occurred in LT, anterior chamber depth (ACD), lens centroid (i.e., ACD + LT/2), and AS length (ASL = ACD + LT) with accommodation (all p < 0.01). There was no significant change in CT with accommodation (p = 0.81). Measured CT, ACD, and lens centroid values were similar to Dubbelman modelled parameters, however AS-OCT overestimated LT and ASL. As expected, the accommodative response was less than the demand. Interestingly, up until approximately 1.5 D of response (2.0 D demand), the anterior crystalline lens surface appears to be the primary correlate. Beyond this point, the posterior lens surface moves posteriorly resulting in an over-all sigmoidal trajectory. he posterior crystalline lens surface demonstrates a sigmoidal response with increasing accommodative effort.
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Croft, Mary Ann, Paul L. Kaufman, Kathryn S. Crawford, Michael W. Neider, Adrian Glasser, and Laszlo Z. Bito. "Accommodation dynamics in aging rhesus monkeys." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 275, no. 6 (December 1, 1998): R1885—R1897. http://dx.doi.org/10.1152/ajpregu.1998.275.6.r1885.

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Accommodation, the mechanism by which the eye focuses on near objects, is lost with increasing age in humans and monkeys. This pathophysiology, called presbyopia, is poorly understood. We studied aging-related changes in the dynamics of accommodation in rhesus monkeys aged 4–24 yr after total iridectomy and midbrain implantation of an electrode to permit visualization and stimulation, respectively, of the eye’s accommodative apparatus. Real-time video techniques were used to capture and quantify images of the ciliary body and lens. During accommodation in youth, ciliary body movement was biphasic, lens movement was monophasic, and both slowed as the structures approached their new steady-state positions. Disaccommodation occurred more rapidly for both ciliary body and lens, but with longer latent period, and slowed near the end point. With increasing age, the amplitude of lens and ciliary body movement during accommodation declined, as did their velocities. The latent period of lens and ciliary body movements increased, and ciliary body movement became monophasic. The latent period of lens and ciliary body movement during disaccommodation was not significantly correlated with age, but their velocity declined significantly. The age-dependent decline in amplitude and velocity of ciliary body movements during accommodation suggests that ciliary body dysfunction plays a role in presbyopia. The age changes in lens movement could be a consequence of increasing inelasticity or hardening of the lens, or of age changes in ciliary body motility.
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Marran, Lynn, and Clifton M. Schor. "Lens induced aniso-accommodation." Vision Research 38, no. 22 (November 1998): 3601–19. http://dx.doi.org/10.1016/s0042-6989(98)00064-9.

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Schachar, Ronald A. "Assessing intraocular lens accommodation." Journal of Cataract & Refractive Surgery 32, no. 5 (May 2006): 702–4. http://dx.doi.org/10.1016/j.jcrs.2006.01.051.

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Wang, Yuanyuan, Yilei Shao, and Yimin Yuan. "Simultaneously measuring ocular aberration and anterior segment biometry during accommodation." Journal of Innovative Optical Health Sciences 08, no. 02 (March 2015): 1550005. http://dx.doi.org/10.1142/s1793545815500054.

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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. In order to measure the alterations of ocular aberration and crystalline lens biometry during dynamic accommodative stimuli, we designed an optical coherence tomography with ultra-long penetration depth (UL-OCT) combined with a Shack–Hartmann wavefront sensor (SHWFS). This integrated set up measures human eye's anterior segment as well as monochromatic high-order aberrations (HOAs) with 6 μm resolution and (1/20) λ accuracy. A total of 10 healthy volunteers without ocular diseases were examined. Upon exposure to accommodative stimuli, the wavefront aberrations became larger. Among the anterior segment biometry, the anterior crystalline lens demonstrated significant curvature during accommodation and was the major cause of high-order aberration. These findings suggest that the front surface of the crystalline lens can significantly affect variation among aberrations, which is a key factor underlying the quality of human vision.
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Gerometta, R., A. C. Zamudio, D. P. Escobar, and O. A. Candia. "Volume change of the ocular lens during accommodation." American Journal of Physiology-Cell Physiology 293, no. 2 (August 2007): C797—C804. http://dx.doi.org/10.1152/ajpcell.00094.2007.

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During accommodation, mammalian lenses change shape from a rounder configuration (near focusing) to a flatter one (distance focusing). Thus the lens must have the capacity to change its volume, capsular surface area, or both. Because lens topology is similar to a torus, we developed an approach that allows volume determination from the lens cross-sectional area (CSA). The CSA was obtained from photographs taken perpendicularly to the lenticular anterior-posterior (A-P) axis and computed with software. We calculated the volume of isolated bovine lenses in conditions simulating accommodation by forcing shape changes with a custom-built stretching device in which the ciliary body-zonulae-lens complex (CB-Z-L) was placed. Two measurements were taken (CSA and center of mass) to calculate volume. Mechanically stretching the CB-Z-L increased the equatorial length and decreased the A-P length, CSA, and lens volume. The control parameters were restored when the lenses were stretched and relaxed in an aqueous physiological solution, but not when submerged in oil, a condition with which fluid leaves the lens and does not reenter. This suggests that changes in lens CSA previously observed in humans could have resulted from fluid movement out of the lens. Thus accommodation may involve changes not only in capsular surface but also in volume. Furthermore, we calculated theoretical volume changes during accommodation in models of human lenses using published structural parameters. In conclusion, we suggest that impediments to fluid flow between the aquaporin-rich lens fibers and the lens surface could contribute to the aging-related loss of accommodative power.
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Zhang, Junna, Yang Ni, Peng Li, Wen Sun, Mengyun Liu, Dongyu Guo, and Chixin Du. "Anterior Segment Biometry with Phenylephrine and Tropicamide during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography." Journal of Ophthalmology 2019 (February 25, 2019): 1–5. http://dx.doi.org/10.1155/2019/6827215.

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Purpose. To investigate the influence of phenylephrine and tropicamide on anterior segment biometry with ultralong scan depth optical coherence tomography (UL-OCT) during accommodation. Methods. In this study, 20 left eyes of healthy volunteers with a mean ± standard deviation age of 31.05 ± 5.84 years and a mean refraction of −1.16 ± 1.11 diopters (range 0∼−3.0 D) were imaged using UL-OCT after instillation of artificial tears, phenylephrine, and tropicamide in three follow-up trials, respectively. At each follow-up trial, two repeated measurements were performed at states of relax and 5D accommodative stimulation. The dimensional parameters included central corneal thickness (CCT), anterior chamber depth (ACD), pupil diameter (PD), lens thickness (LT), and horizontal radii of the lens anterior and posterior surface curvatures (LAC and LPC). Results. Tropicamide led to larger pupil, deeper ACD, thinner LT, and flatter crystalline lens surface (P<0.05). Phenylephrine induced an increase in PD (P<0.05), while no significant changes were seen in ACD, LT, LAC, and LPC (P>0.05). CCT did not change after both phenylephrine and tropicamide instillation in this study (P>0.05). Tropicamide induced the loss of accommodation and phenylephrine achieved pupil dilation without affecting the accommodation. PD, ACD decreased, LT increased significantly and the anterior and posterior surface of the lens in a 6.294 mm of diameter optical zone became steeper during accommodation after administration of phenylephrine (P<0.05). Conclusion. The anterior segment physiology changed after tropicamide instillation. Besides, tropicamide induced the loss of accommodation and phenylephrine preserved the accommodation with a larger pupil. And, the anterior and posterior surface of lens in a 6.294 mm of diameter optical zone became steeper during the accommodation.
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Ruan, Xiaoting, Zhenzhen Liu, Lixia Luo, and Yizhi Liu. "The Structure of the Lens and Its Associations with the Visual Quality." BMJ Open Ophthalmology 5, no. 1 (September 2020): e000459. http://dx.doi.org/10.1136/bmjophth-2020-000459.

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In humans, the lens is the organ with the ability to change morphology and refractive power, designated as accommodation, to focus light from various distances and obtain clear retinal image. The accommodative ability of the lens depends on its structure and biological parameters. The lens grows throughout the life, forming specific lens sutures and a unique gradient refractive index, and possesses regenerative ability under certain circumstances. Minimally invasive lens surgery that preserves endogenous lens epithelial stem/progenitor cells (LECs) can achieve functional lens regeneration in humans. The lens is the main source of intraocular aberration, especially intraocular higher-order aberrations (IHOAs) which is found to be binocularly symmetrical in phakic eyes. There is a compensation mechanism between corneal aberrations and lens aberrations. Therefore, the structure and the biological parameters of the lens, the binocular relationship of the lens and the correlation between the lens and cornea affect visual quality. This paper summarises the above findings and their current and potential applications in refractive surgeries, providing a comprehensive understanding of the lens as a strong determinant of visual quality in the optical system.
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Dissertations / Theses on the topic "Accommodation of the lens"

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Urs, Raksha. "Investigation of Accommodation and Presbyopia using Ultrasound Imaging during Ex Vivo Simulated Accommodation." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/360.

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The goal of this project is to obtain quantitative images of the lens and the ciliary body to validate EVAS-II (Second generation Ex Vivo Accommodation Simulator). To accomplish this goal it was necessary to develop methods, instrumentation and image processing techniques to acquire 3D images in EVAS-II, using UBM (Ultrasound Bio Microscope), and to apply these techniques to non-human primate eyes. The lens studies included measurement of speed of sound in the lens to reconstruct accurate images of the lens, development of instrumentation to measure the un-distorted lens shape and development of a mathematical model to quantify the whole lens shape. Speed measurements showed that the speed of sound exhibits a gradient profile in the equatorial plane, similar to refractive index and protein distributions in the lens. Lens shape measurements showed that the UBM can be used to accurately measure thickness, diameter, cross-sectional area, volume and surface area of the lens. The ciliary body studies included development of instrumentation and algorithms to obtain 3-D images of tissue in EVAS-II and development of methodology to quantify ciliary body movement during stretching. Studies showed that the accommodation process in young baboon eyes in EVAS-II is comparable to the in vivo process in rhesus monkeys. The UBM can be used to obtain reliable quantitative information about the lens and the ciliary body. 3-D UBM enables monitoring of ciliary body motion of the entire accommodative apparatus.
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Rabie, E. P. "Biometry of the crystalline lens during accommodation." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378316.

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Otero, Molins Carles. "Lens-based technologies to study accommodation and refraction." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/461452.

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A visual stimulus can be presented in free space or through lens-based systems. Interestingly, it has been reported many times in the past that some subjects have poorer accommodative responses when optically stimulated, with no aparent reason. However, this limitation has not precluded the use of lens-based systems in ophthalmic devices, virtual reality displays or research setups, probably because it is outweighed by some advantages such as the computer-control of the focal plane of the stimuli. Under this general context, the objective of this thesis is to apply lens-based technologies (from computer-controlled electró-optical lenses to Badal Systems) to study accommodation and refraction. The methodology of this thesis is structured in 6 studies. The first three studies investigate the response of the accommodative system when optically-stimulated with a Badal optometer. The remaining 3 studies take advantage of electro-optical varifocal systems to investigate new methodologies related to the automated subjective refraction and the accommodative facility test. Concretely, the fourth study is a clinical validation of a new automated refraction algorithm and is the only study thatworks specifically on eye¿s refraction. The fifth and sixth studies use an electro-optical liquid lens to present a repeated step-like stimulus at different accommodative distances. The fifth study validates a new accommodative facility test that integrates both the far and near accommodative facility testwith random changes of accommodative stimulus and, the sixth study explores how the predictability of a stimulus affects the accommodation dynamics. The results of the first three studies show that previously reported differences in accommodative response when using lens-based methods compared to free space viewing may be explained by the effect of other factors such as the refractive error or field of view rather than the method to stimulate accommodation. It is also shown that the most accurate accommodative responses are obtained for fields between 8º and 10º which suggests that there may be an optimum peripheral retinal image size for accommodation stimulation. Also, it is shown that the only factor that in isolation significantly affects the accuracy of the accommodative responses is the type of refractive error. And finally, it is also shown that the accuracy of the accommodation response generally improves with a 2-dimensional stimulus with apparent depth cues and simulated out-of-focus blur in a relatively large field of view. Even though these conditions may not be adequate for all individuals, they can be used to improve the overall visual comfort in those virtual reality systems that use a varifocal optical system to change the focal plane of a 2-dimensional surface or visual simulators. The results of the study 4 show the first implementation of a potential novel method of performing non1cycloplegic subjective refraction in adults without clinician suport. Although this method has some limitations thatwarrant further research and it should be tested in a wider population in terms of age4 refraction and different ocular conditions4 it is precise and more accurate than objective refraction methods and it has the potential to be incorporated in novel lens1based technologies to improve primary eye care services in developing countries. And finally, the last two studies showed also the first implementation of a new accommodative facility test that integrates both the far and near accommodative facility testwith random changes of accommodative stimulus. This new methodology is a faster test than performing both the near and far accommodative tests and it provides more information than conventional accommodative facility tests. Additionally these two studies showed that the prediction operator does not exist in accommodation and the unpredictability of the stimulus does not affect the accommodation dynamics.
Un estímul visual es pot presentar a l'espai lliure o a través de sistemes basats en lents. Curiosament, en el passat s'ha reportat moltes vegades que alguns subjectes acomoden de forma més pobre quan aquesta és estimulada per mitjans òptics. Tanmateix, aquesta limitació no ha impedit l'ús de sistemes basats en lents en dispositius oftàlmics, sistemes de realitat virtual o muntatges òptics de recerca, probablement perquè es compensen les limitacions amb alguns avantatges com el control per ordinador del pla focal del estímul. En aquest context general, l'objectiu d'aquesta tesi és aplicar tecnologies basades en lents (des de lents electró-òptiques controlades per ordinador fins a sistemes Badal) per estudiar l'acomodació i refracció. La metodologia d'aquesta tesi està estructurada en 6 estudis. Els primers tres estudis investiguen la resposta del sistema acomodatiu quan està estimulat òpticament amb un optòmetre Badal. Els 3 estudis restants aprofiten els sistemes varifocals electró-òptics per investigar noves metodologies relacionades amb la refracció subjectiva automàtica i la prova de flexibilitat acomodativa. Concretament, el quart estudi és una validació clínica d'un nou algorisme de refracció automatitzat i és l'únic estudi que treballa específicament en la refracció ocular. Els estudis cinquè i sisè utilitzen una lent òptica electró-òptica per presentar un estímul repetit a diferents distàncies acomodatives. El cinquè estudi valida una nova prova híbrida acomodativa que integra la prova de flexibilitat acomodativa llunyana i propera amb canvis aleatoris d'estímul acomodatiu i, el sisè estudi explora com la predictibilitat d'un estímul afecta la dinàmica acomodativa. Els resultats dels tres primers estudis mostren que les diferències reportades anteriorment en la resposta acomodativa quan s'utilitzen mètodes basats en lents en comparació amb la visualització d'estímuls en l'espai lliure es pot explicar per l'efecte de factors com l'error refractiu o el camp de visió més que en el mètode d'estimulació d'acomodació. També es demostra que l'acomodació és més precisa per a camps visuals entre 8 i 10º, el que suggereix que hi pot haver una mida d'imatge retiniana òptima per a l'estimulació de l'acomodació. A més, es demostra que l'únic factor que afecta aïlladament l'exactitud de la resposta acomodativa és el tipus d'error refractiu. També, es demostra que la precisió de la resposta acomodativa generalment millora amb un estímul bidimensional amb pistes de profunditat perifèriques i desenfoc simulat per a un camp de visió relativament gran. Aquestes condicions es poden utilitzar per millorar el confort visual en aquells sistemes de realitat virtual o simuladors visuals que utilitzen un sistema òptic varifocal per canviar el pla focal d'una superfície bidimensional. Els resultats de l'estudi 4 mostren la primera implementació d'un nou mètode potencial per a la realització de refracció subjectiva no cicloplègica en adults sense suport clínic. Encara que aquest mètode requereix encara una investigació addicional en una població més àmplia en termes d'edat, refracció i condicions oculars diferents, és més precís que els mètodes de refracció objectius i té el potencial d'incorporar-se a noves tecnologies basades en lents per millorar els serveis d'atenció primària en països en vies de desenvolupament. Finalment, els dos últims estudis mostren la primera implementació d'una nova prova de flexibilitat acomodativa que integra tant la prova llunyana i propera, amb canvis aleatoris d'estímul acomodatiu. Aquesta nova metodologia és una prova més ràpida que l'execució de les proves d'acomodació pròxima i llunyana i proporciona més informació que les proves de flexibilitat acomodativa per separat. Addicionalment, aquests dos estudis mostren que la capacitat predictiva en l'acomodació es insignificant i que la imprevisibilitat de l'estímul no afecta la dinàmica acomodativa
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Nankivil, Derek. "A Second Generation Ex-Vivo Accommodation Simulator: Design and Calibration." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_theses/161.

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Presbyopia is the progressive decrease in accommodative ability with age, and it implies a major loss of visual function. Presbyopia is the only condition of the eye which affects everyone who lives beyond 50 years of age. As part of a joint effort, the Ophthalmic Biophysics Center at the Bascom Palmer Eye Institute and the Vision Cooperative Research Centre at the University of New South Wales, developed two different ex-vivo accommodation simulators (EVAS) to examine the mechanisms of accommodation and presbyopia, and to test and validate new ophthalmic surgical procedures such as lens refilling. The purpose of this thesis is to mechanically and optically calibrate the second generation instrument (EVASII), and to compare it to the first generation design (EVASI). To validate the optical measurements of EVASII, an optical calibration has been performed, yielding a lens power measurement system with a mean accuracy of ±0.56D. To enhance the optical capabilities and tissue dissection options, the mechanics of mounting the tissue has been improved by using magnetic mounts, and the mechanical calibration of EVASII, yielded a force measurement system with a mean uncertainty of ±0.81g Also, a comparison of EVASII and EVASI has been performed, showing that the results of the two systems are significantly different; however, both systems successfully simulate accommodation. Thus, general trends concerning efficacy and optimization of surgical procedures as well as age related accommodative changes can be compared for each individual system.
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Heistand, Mark Richard. "Biomechanics of the lens capsule." Texas A&M University, 2004. http://hdl.handle.net/1969.1/2726.

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Knowledge of the mechanics of the lens capsule is crucial for improving cataract surgery as well as understanding better the physiological role of the lens capsule in the process of accommodation. Previous research on the mechanical properties of the lens capsule contains many gaps and contradictions due to experimental limitations and inappropriate assumptions. Thus, the goal of this work is to quantify fully the regional, multiaxial mechanical behavior of the lens capsule and to calculate the change in stress and strain fields as a result of cataract surgery. Determining in situ the multiaxial mechanical behavior of the lens capsule required the design and construction of an experimental device capable of altering stresses in the capsule while measuring localized surface deformations. Tests performed on this device reveal that the meridional and circumferential strains align with the principal directions and are equivalent through most of the anterior lens capsule, except close to the equator where the meridional strain is greater. Furthermore, preconditioning effects were also found to be significant. Most importantly, however, these tests provide the data necessary for calculating material properties. This experimental system is advantageous in that it allows reconstruction of 3D geometry of the lens capsule and thereby quantification of curvature changes, as well as measurement of surface deformations that result from various surgical interventions. For instance, a continuous circular capsulorhexis (CCC) is commonly used during cataract surgery to create a hole in the anterior lens capsule (typically with a diameter of 5 mm). After the introduction of a CCC, strain was found to redistribute evenly from the meridional direction (retractional strain) to the circumferential direction (extensional strain), where both directional components of strain reached magnitudes up to 20% near the edge of the CCC. Furthermore, the curvature was found to increase at the edge of the CCC and remain the same near the equator, indicating that the mere introduction of a hole in the lens capsule will alter the focal characteristics of the lens and must therefore be considered in the design of an accommodative intraocular lens.
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Cheng, Desmond. "Bifocal lens control of myopia progression in children." Queensland University of Technology, 2008. http://eprints.qut.edu.au/29688/.

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This research investigated underlying issues that were critical to the success of the bifocal trial and comprised of three studies. The first study evaluated if Chinese-Canadian children were suitable subjects for the bifocal trial. The high prevalence of myopia in Chinese children suggests that genetic input plays a role in myopia development, but the rapid increase in prevalence over the last few decades indicates environmental factors are also important. Since this bifocal trial was conducted in Canada, this work aimed to determine whether Chinese children who had migrated to Canada would still have high myopia prevalence and a high rate of myopia progression. The second study determined the optimal bifocal lens power for myopia treatment and the effect of incorporating base-in prism into the bifocal. In the majority of published myopia control studies, the power of the prescribed near addition was usually predetermined in the belief that the near addition would always help to improve the near focus. In fact, the effect of near addition on the accommodative error might be quite different even for individuals in which the same magnitude of accommodation lag had been measured. Therefore, this work was necessary to guide the selection of bifocal and prism powers most suitable for the subsequent bifocal trial. The third study, the ultimate goal of this research, was to conduct a longitudinal clinical trial to determine if bifocals and prismatic bifocals could control myopia progression in children.
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Ziebarth, Noel Marysa. "Atomic Force Microscopy Measurement of the Elastic Properties of the Lens." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/181.

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The goal of this project was to develop techniques and instrumentation to measure the elastic properties of the lens and lens capsule in situ and their changes with age using Atomic Force Microscopy (AFM). The studies include the construction, characterization, and calibration of laboratory-based Atomic Force Microscope (AFM) to measure mechanical properties of ophthalmic tissues. Atomic Force Microscopy is a nanoscale imaging technique that has been applied to mechanical property measurement through nanoindentation. Young's modulus of elasticity is determined by monitoring the cantilever deflections when it contacts the sample. The studies also include the development of tissue preparation techniques to enable measurement of the lens elasticity using AFM. This study found that lens capsule elasticity decreases with age, outer lens cortex elasticity remains constant with age, and the inner lens cortex is stiffer than the outer lens cortex. The effect of the changing biometry and mechanical properties with age was investigated by developing a mathematical model of accommodation. These changes will be the limiting factor to accommodative amplitude. Changes in lens capsule mechanical properties will affect the maximal accommodative amplitude in older eyes.
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Borja, David. "Dynamic Optical Model of the Primate Crystalline Lens and Implications for the Restoration of Accommodation." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/355.

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The human crystalline lens is a complex, inhomogeneous and dynamic optical element which enables the eye to adjust focus in a process known as accommodation. Age related changes in the optical and mechanical properties of the lens cause a loss in accommodative ability leading to a condition known as presbyopia. Several experimental surgical techniques are under development for the correction of presbyopia. The goal of this dissertation is to better understand the relationship between the crystalline lens shape, its non-uniform refractive index gradient and its optical power and their changes with age and accommodation. In this study direct lens power and shape measurements were acquired on isolated lenses, and on lenses mounted in a lens stretching system designed to simulate accommodation. Several lens shape and power measurement techniques were developed for this study including a Scheimpflug camera system optimized for imaging the crystalline lens. Direct measurements of lens shape and power were used to develop an age-dependent optical-mechanical model of the lens during accommodation. The study shows that the normal growth of the lens is a major contributor to the progressive loss of accommodation amplitude, independent of changes in the elastic properties of the lens. These findings suggest that accommodation can be restored by refilling the lens with a material having a uniform refractive index.
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Schultz, Kristin E. "Accommodative microfluctuations, crystalline lens tension, ciliary body thickness, and refractive error in children." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1240445960.

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Ruggeri, Marco. "Extended Depth Optical Coherence Tomography for Anterior Segment and Accommodation Imaging in Real-Time." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/686.

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The changes in the human crystalline lens shape and its internal structure during accommodation and with aging are a fundamental component of the dynamic mechanism of accommodation and presbyopia, the loss of near vision with age. A better understanding of the crystalline lens changes during accommodation will help in developing new treatments to correct for presbyopia. The goal of this dissertation is to design and develop an imaging system to study the dynamic changes in lens shape during accommodative response. An imaging system based on spectral domain optical coherence tomography (SD-OCT) was developed with long axial range, high axial and lateral resolution and high speed for in vivo imaging the anterior segment along its entire length at video-rate. A slit-lamp mounted optical delivery scanning device for the extended depth SD-OCT system was developed. The delivery system was combined with a custom made unit that provides accommodation and disaccommodation step stimuli. A method to correct for the distortions of the OCT images was also developed that provides corrected two dimensional biometric data at different accommodative states.
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Books on the topic "Accommodation of the lens"

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Intraocular lens power calculations. Thorofare, NJ: SLACK, 2004.

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Intraocular lens power calculations: Avoiding the errors. Glendale, Calif: News Circle Pub. House, 1996.

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Caroline, Christie, ed. Clinical optics and refraction: A guide for optometrists, contact lens opticians, and dispensing opticians. Edinburgh: Butterworth-Heinemann, 2007.

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Milder, Benjamin. The fine art of prescribing glasses without making a spectacle of yourself. 3rd ed. Gainesville, Fla: Triad Pub., 2004.

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Milder, Benjamin. The fine art of prescribing glasses without making a spectacle of yourself. 2nd ed. Gainesville, Fla: Triad Pub. Co., 1991.

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Daheim, Mary. Legs Benedict. New York: HarperCollins, 2007.

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Canada. Dept. of Employment and Immigration. Accommodation. [Ottawa]: Supply and Services, 1988.

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Contact lens optics and lens design. 3rd ed. Edinburgh: Elsevier Butterworth-Heinemann, 2006.

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Contact lens optics and lens design. 2nd ed. Oxford: Butterworth-Heinemann, 1995.

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Canada, Canada Public Works and Government Services. Client accommodation: Accommodation use in government. Ottawa, Ont: Minister of Supply and Services Canada = Ministre des approvisionnements et services Canada, 1995.

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Book chapters on the topic "Accommodation of the lens"

1

Skalicky, Simon E. "The Lens and Accommodation." In Ocular and Visual Physiology, 47–65. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-287-846-5_4.

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Miyao, Masaru. "Lens Accommodation While Viewing 3D Video Clips." In Current Topics in Environmental Health and Preventive Medicine, 13–24. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1601-2_2.

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Storey, John K., Cindy Tromans, and Ezra Rabie. "Continuous biometry of the crystalline lens during accommodation." In Documenta Ophthalmologica Proceedings Series, 117–23. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-0601-3_13.

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Hasegawa, Satoshi, Masako Omori, Tomoyuki Watanabe, Kazuhiro Fujikake, and Masaru Miyao. "Lens Accommodation to the Stereoscopic Vision on HMD." In Lecture Notes in Computer Science, 439–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-02771-0_49.

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Goldberg, Daniel B. "Biomechanics of the Lens and Hydrodynamics of Accommodation." In Ocular Rigidity, Biomechanics and Hydrodynamics of the Eye, 117–26. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64422-2_8.

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Baumeister, Martin, and Thomas Kohnen. "Accommodating Intraocular Lens." In Encyclopedia of Ophthalmology, 1–2. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-642-35951-4_384-4.

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Baumeister, Martin, and Thomas Kohnen. "Accommodating Intraocular Lens." In Encyclopedia of Ophthalmology, 4–5. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-540-69000-9_384.

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Danisi, Carmelo, Moira Dustin, Nuno Ferreira, and Nina Held. "Housing and Accommodation." In IMISCOE Research Series, 331–87. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69441-8_8.

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AbstractThe SOGI claimants we interviewed were often more or as concerned about their living conditions in the host country than they were with the asylum process. This was especially the case in the interviews in Germany and Italy, where issues around housing and accommodation often dominated the discussion, both in interviews with SOGI claimants and with professionals. For instance, Elias, a lawyer in Germany, told us that his clients were often less concerned about the legal procedure and more about ‘the problems around it. Less legally, less tangibly in relation to the procedure, but rather: “What about the accommodation situation?”; “How can I rebuild a life appropriate to my sexual orientation?”’.
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Yamakawa, Tatsuya, Hideaki Takada, Munekazu Date, Takehito Kojima, Ichizo Morita, Yuma Honda, and Masaru Miyao. "Measurement of Lens Accommodation During Viewing of DFD Images." In Universal Access in Human-Computer Interaction. Access to Interaction, 285–96. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-20681-3_27.

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Bando, T., N. Hara, M. Takagi, H. Hasebe, R. Takada, and H. Toda. "Vergence eye movement and lens accommodation: cortical processing and neuronal pathway." In Accommodation and Vergence Mechanisms in the Visual System, 43–50. Basel: Birkhäuser Basel, 2000. http://dx.doi.org/10.1007/978-3-0348-7586-8_5.

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Conference papers on the topic "Accommodation of the lens"

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Pedrigi, Ryan M., and Jay D. Humphrey. "Biomechanics of the Human Anterior Lens Capsule." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-192073.

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The primary function of the lens of the eye, termed accommodation, is to precisely focus light onto the retina by changing curvature and corresponding refractive power. Investigators have long sought to understand the mechanism of accommodation in terms of interactions of the constituent tissues, which recently has been aided by biomechanical modeling. Such models depend heavily on accurate measurements of tissue mechanical properties and seek to predict stresses and strains. A critical component of the accommodative apparatus is the lens capsule, a bag-like membrane that encapsulates the lens nucleus and cortex and mediates tractions imposed onto this structure by the ciliary body. In addition to this physiologic process during normalcy, the lens capsule also plays a fundamental role in cataract surgery; a procedure that involves three basic steps: a quarter of the anterior lens capsule is removed via the introduction of a continuous circular capsulorhexis (CCC), the lens is broken up and suctioned out, and an artificial intraocular lens (IOL) is placed within the remnant capsular bag. Although novel IOL designs have decreased post-surgical complications, they currently lack the important feature of accommodation. Therefore, mechanical analysis of the lens capsule will allow for an understanding of its interaction with an implant that may further assist in the design of future accommodating IOLs (AIOLs). Here, we report a novel experimental approach to study in situ the regional, multiaxial mechanical behavior of both normal and diabetic human anterior lens capsules. Furthermore, we use these data to calculate material parameters in a nonlinear stress-strain relation via a custom sub-domain inverse finite element method (FEM). These parameters are then used to predict capsular stresses in response to imposed loads using a forward FEM model.
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Rosenshein, Joseph S., and Frank Rosenbaum. "Accommodation in Crystalens Intraocular Lens." In Frontiers in Optics. Washington, D.C.: OSA, 2005. http://dx.doi.org/10.1364/fio.2005.fthr1.

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Breitenfeld, Patrick, T. Ripken, and H. Lubatschowski. "FEM-Simulation of the Human Lens during Accommodation." In European Conference on Biomedical Optics. Washington, D.C.: OSA, 2005. http://dx.doi.org/10.1364/ecbo.2005.sub2.

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Doornaert, Dries, Christ Glorieux, Herbert De Gersem, Robert Puers, Werner Spileers, and Johan Blanckaert. "Intraocular electro-optic lens with ciliary muscle controlled accommodation." In 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2013. http://dx.doi.org/10.1109/embc.2013.6610219.

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Guo, Qi, Emma Alexander, and Todd Zickler. "Focal Track: Depth and Accommodation with Oscillating Lens Deformation." In 2017 IEEE International Conference on Computer Vision (ICCV). IEEE, 2017. http://dx.doi.org/10.1109/iccv.2017.110.

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Koretz, Jane F., and Christopher A. Cook. "The Internal Dynamics of the Human Crystalline Lens with Accommodation." In Vision Science and its Applications. Washington, D.C.: OSA, 2001. http://dx.doi.org/10.1364/vsia.2001.mb5.

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Ripken, T., U. Oberheide, C. Ziltz, W. Ertmer, G. Gerten, and H. Lubatschowski. "Fs-laser induced elasticity changes to improve presbyopic lens accommodation." In Biomedical Optics 2005, edited by Fabrice Manns, Per G. Soederberg, Arthur Ho, Bruce E. Stuck, and Michael Belkin. SPIE, 2005. http://dx.doi.org/10.1117/12.588242.

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Breitenfeld, P., T. Ripken, and H. Lubatschowski. "Finite element method-simulation of the human lens during accommodation." In European Conference on Biomedical Optics 2005, edited by Hubert van den Bergh and Alfred Vogel. SPIE, 2005. http://dx.doi.org/10.1117/12.633086.

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Ziebarth, Noel, Fabrice Manns, Ana-Carolina Acosta, and Jean-Marie Parel. "Non-contact optical measurement of lens capsule thickness during simulated accommodation." In Biomedical Optics 2005, edited by Fabrice Manns, Per G. Soederberg, Arthur Ho, Bruce E. Stuck, and Michael Belkin. SPIE, 2005. http://dx.doi.org/10.1117/12.597648.

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Reilly, Matthew A. "Is Presbyopia Caused by Lens Growth-Induced Residual Stresses?" In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14528.

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Prevailing wisdom holds that increasing lens stiffness causes presbyopia. Treatments for presbyopia have therefore focused on altering the mechanical properties of the ocular lens. The present work shows an age-related decline in accommodation amplitude may be predicted without invoking changes in lens stiffness.
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Reports on the topic "Accommodation of the lens"

1

Zehner, Gregory F., and Jeffrey A. Hudson. TH-67 Size Accommodation Report. Fort Belvoir, VA: Defense Technical Information Center, June 2001. http://dx.doi.org/10.21236/ada406367.

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Rader, Daniel John, Jaime N. Castaneda, John Robert Torczynski, Thomas W. Grasser, and Wayne Merle Trott. Measurements of thermal accommodation coefficients. Office of Scientific and Technical Information (OSTI), October 2005. http://dx.doi.org/10.2172/876357.

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Robinette, Kathleen M. Maximizing Anthropometric Accommodation and Protection. Fort Belvoir, VA: Defense Technical Information Center, August 2007. http://dx.doi.org/10.21236/ada478337.

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Tucker, Heather, and Jennifer Crawford. Cockpit Accommodation in USN/USMC Helicopters. Fort Belvoir, VA: Defense Technical Information Center, January 2000. http://dx.doi.org/10.21236/ada384560.

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Zehner, Gregory F., and Jeffrey A. Hudson. Body Size Accommodation in USAF Aircraft. Fort Belvoir, VA: Defense Technical Information Center, January 2002. http://dx.doi.org/10.21236/ada405598.

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Spangler, Stanley E. Force and Accommodation in World Politics. Fort Belvoir, VA: Defense Technical Information Center, August 1991. http://dx.doi.org/10.21236/ada421926.

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Helpman, Elhanan, and Leonardo Leiderman. Real Wages, Monetary Accommodation, and Inflation. Cambridge, MA: National Bureau of Economic Research, October 1989. http://dx.doi.org/10.3386/w3146.

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Krider, J. Lithium Lens Interlocks. Office of Scientific and Technical Information (OSTI), December 1985. http://dx.doi.org/10.2172/948901.

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Zehner, Gregory F. Prediction of Anthropometric Accommodation in Aircraft Cockpits. Fort Belvoir, VA: Defense Technical Information Center, June 2001. http://dx.doi.org/10.21236/ada399750.

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Myers, S. M., D. M. Follstaedt, J. A. Floro, S. R. Lee, L. R. Dawson, and J. L. Reno. Nanocavity effects on misfit accommodation in semiconductors. Office of Scientific and Technical Information (OSTI), April 1997. http://dx.doi.org/10.2172/468586.

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