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Recep ÖF, Kocabas DO, Kiziltoprak H, Ozulken K. Effects on Wavefront Aberration after Short-term Wear of Senofilcon A Photochromic Contact Lens. Klin Monbl Augenheilkd 2022. [PMID: 36347502 DOI: 10.1055/a-1973-8904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND To assess the variability in wavefront aberrations with short-term wear of photochromic senofilcon A contact lenses in both its activated and inactive states. METHODS AND MATERIAL In this cross-sectional study, 20 participants who had previously used soft contact lenses were enrolled. Corneal aberrometry measurements were performed on each subject, without contact lenses, using Sirius Scheimpflug-Placido topography. The photochromic lenses were illuminated using a blue-violet light (λ max = 420 nm) so as to provoke an activated state, and measurements were taken with the lenses inserted, in both states. The root mean square (RMS) of the aberrations was calculated, and the higher- and lower-order aberrations, astigmatism, coma, spherical aberration, and trefoil measurements were evaluated using a 5.0-mm pupil diameter. RESULTS The average contact lens sphere power was - 2.33 ± 1.07 D. The mean refractive errors with contact lens wear were 0.07 ± 0.18 D for the sphere and - 0.26 ± 0.15 D for the cylinder. The mean RMS values for all the corneal aberrations showed no statistically significant differences with and without contact lenses (p > 0.05). In a bivariate correlation analysis, there was a positive correlation between contact lens sphere power and coma (vertical and horizontal) in the activated state (r = 0.455, p = 0.44 and r = 0.495, p = 0.27, respectively). CONCLUSION The photochromic contact lenses did not influence ocular aberration during short-term wear, even when the photochromatic additive was activated. This property may help to provide more comfortable vision with lens wear. This finding needs to be verified by further studies.
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Affiliation(s)
| | | | - Hasan Kiziltoprak
- Ophthalmology, Adıyaman University Training and Research Hospital, Adıyaman, Turkey
| | - Kemal Ozulken
- Ophthalmology, TOBB Economics and Technology University Faculty of Medicine, Ankara, Turkey
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Lara-Lacárcel F, Marín-Franch I, Fernández-Sánchez V, Riquelme-Nicolás R, López-Gil N. Objective changes in astigmatism during accommodation. Ophthalmic Physiol Opt 2021; 41:1069-1075. [PMID: 34414587 DOI: 10.1111/opo.12863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/07/2021] [Accepted: 06/07/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE Previous studies have shown small but clinically significant changes in the power and axis of astigmatism when the eye accommodates. Monocular objective measurements of the eye during accommodation, when the object approaches the eye without convergence, also reveal small astigmatic changes. Moreover, it is known that the eye exhibits ocular cyclotorsion at different gaze angles. Since accommodation and convergence normally occur simultaneously, we studied the change in the magnitude and axis of astigmatism during accommodation for different convergence angles. METHODS The left eye of 15 subjects between 20 and 49 years old (mean 28.5 ± 9.7 years) having ≤1.5 D astigmatism was evaluated. Measurements were made using a Shack-Hartmann aberrometer for an accommodation range of +0.50 D to -10 D in 0.50 D steps, and for four monocular convergence demands: 0°, 5°, 10° and 15°. Statistical analysis used power vectors to quantify the change in cylinder power and axis for each accommodation and convergence demand with age. RESULTS Jackson cross-cylinder component J45 did not change during accommodation for all vergences tested. However, J0 changed by an average of -0.02 D per dioptre of accommodation (D/Dacc) for convergence demands of 0°, 5° and 10° and -0.03 D/Dacc for the 15° demand. This corresponds to an average cylinder power change of -0.05 D/Dacc for convergences of 0°, 5° and 10° and -0.08 D/Dacc for 15° of convergence. The cylinder axis always changed towards 90° (against-the-rule), and age did not play a significant role. CONCLUSIONS Except for accommodation demands >4 D, we did not find a clinically significant change in astigmatism for convergence angles up to 15º. The small changes in cylinder power and axis may be due to shifts in the position of the crystalline lens during accommodation.
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Affiliation(s)
| | - Iván Marín-Franch
- Faculty of Optics and Optometry, University of Murcia, Murcia, Spain.,Computational Optometry, Atarfe, Spain
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Montés-Micó R, Pastor-Pascual F, Artiaga-Elordi E, Ruiz-Mesa R, Tañá-Rivero P. In vivo optical quality of posterior-chamber phakic implantable collamer lenses with a central port. EYE AND VISION 2021; 8:30. [PMID: 34392836 PMCID: PMC8365931 DOI: 10.1186/s40662-021-00251-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 07/15/2021] [Indexed: 11/10/2022]
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.
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Affiliation(s)
- Robert Montés-Micó
- Optics and Optometry & Vision Sciences Department, University of Valencia, c/o Dr Moliner 50, 46100, Valencia, Spain. .,Oftalvist Clinic, Valencia, Spain.
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Rae SM, Price HC. The effect of soft contact lens wear and time from blink on wavefront aberration measurement variation. Clin Exp Optom 2021; 92:274-82. [DOI: 10.1111/j.1444-0938.2009.00377.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Sheila M Rae
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, United Kingdom
E‐mail:
| | - Holly C Price
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, United Kingdom
E‐mail:
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Theoretical Effect of Coma and Spherical Aberrations Translation on Refractive Error and Higher Order Aberrations. PHOTONICS 2020. [DOI: 10.3390/photonics7040116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
(1) Background: The purpose of the study is to present a simple theoretical account of the effect of translation of coma and spherical aberrations (SA) on refractive error and higher order aberrations. (2) Methods: A computer software algorithm was implemented based on previously published methods. The effect of translation (0 to +1 mm) was analyzed for SA (0 to +2 µm) and coma (0 to +2 µm) for a circular pupil of 6 mm, without any rotation or scaling effect. The relationship amongst Zernike representations of various aberrations was analyzed under the influence of translation. (3) Results: The translation of +0.40 µm of SA (C[4,0]) by +0.25 mm with a pupil diameter of 6mm resulted in induction of tilt (C[1,1]), −0.03D defocus (C[2,0]), +0.03D astigmatism (C[2,2]) and +0.21 µm coma (C[3,1]). The translation of +0.4 µm of coma (C[3,1]) by +0.25 mm with a pupil diameter of 6 mm resulted in induction of tilt (C[1,1]), −0.13D defocus (C[2,0]) and +0.13D astigmatism (C[2,2]). A theoretical quantitative relationship between SA, coma, astigmatism and defocus is presented under the influence of translation. (4) Conclusion: The results can act as a guide for the clinician, in order to readily assess theoretical impact of wavefront map translation from pupil center to the visual axis. The resultant refractive coupling has to be taken into consideration especially when treating eyes with an abnormal corneal shape and/or large pupil center to corneal vertex chord.
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Jaskulski M, Marín-Franch I, Bernal-Molina P, López-Gil N. The effect of longitudinal chromatic aberration on the lag of accommodation and depth of field. Ophthalmic Physiol Opt 2017; 36:657-663. [PMID: 27790774 DOI: 10.1111/opo.12320] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 08/19/2016] [Indexed: 11/28/2022]
Abstract
PURPOSE Longitudinal chromatic aberration is present in all states of accommodation and may play a role in the accommodation response and the emmetropisation process. We study the change of the depth of field (DOFi) with the state of accommodation, taking into account the longitudinal chromatic aberration. METHODS Subjective DOFi was defined as the range of defocus beyond which the blur of the target (one line of optotypes of 0.1 logMAR shown on a black-and-white microdisplay, seen through different colour filters) was perceived as objectionable. The subject's eye was paralysed and different, previously-measured accommodative states (corresponding to the accommodative demands of 0D, 2D and 4D) were simulated with a deformable mirror. Different colour conditions (monochromatic red, green and blue and polychromatic (white) were tested. The DOFi was measured subjectively, using a motorised Badal system. RESULTS Taking as reference the average accommodative response for the white stimulus, the blue response exhibits on average a lead of 0.45 ± 0.09D, the green a negligible lead of 0.07 ± 0.02D and red a lag of 0.49 ± 0.10D. The monochromatic DOFi, calculated by averaging DOFi over the red, green and blue colour conditions for each accommodative demand was 1.10 ± 0.10D for 0D, 1.20 ± 0.08D for 2D, and 1.26 ± 0.40D for 4D. The polychromatic white DOFi were greater than the average monochromatic DOFi by 19%, 9% and 14% for 0D, 2D, and 4D of accommodative demand, respectively. CONCLUSION The longitudinal chromatic aberration causes a dioptric shift of the monochromatic accommodation response. The study did not reveal this shift to depend on the accommodative demand or to have an effect on the DOFi.
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Affiliation(s)
| | - Iván Marín-Franch
- CiViUM Research Group, University of Murcia, Spain, Spain.,Grupo de Investigación en Optometría, University of Valencia, Spain
| | - Paula Bernal-Molina
- CiViUM Research Group, University of Murcia, Spain, Spain.,Grupo de Investigación en Optometría, University of Valencia, Spain
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Grewe A, Hillenbrand M, Sinzinger S. Aberration analysis of optimized Alvarez-Lohmann lenses. APPLIED OPTICS 2014; 53:7498-7506. [PMID: 25402917 DOI: 10.1364/ao.53.007498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this paper aberrations in Alvarez-Lohmann lenses are analyzed, and a semi-analytical strategy for compensation is derived. An x-y polynomial model is used to describe the aberrations and classify them into static and dynamic components. The lenses are enhanced by higher-order polynomials, and a numerical optimization process is used to determine the most influential coefficients. Two simulations of corrected systems are presented. The first one is optimized for on-axis imaging. The second system is optimized for multiple field points and shows the limitations of a single Alvarez-Lohmann lens. Two systems overcoming these limitations by introducing additional optical surfaces are presented, and their performance is analyzed in simulations.
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Optical quality of aspheric toric intraocular lenses at different degrees of decentering. Graefes Arch Clin Exp Ophthalmol 2014; 252:969-75. [DOI: 10.1007/s00417-014-2629-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/04/2014] [Accepted: 03/28/2014] [Indexed: 01/19/2023] Open
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Sasian J, Acosta E. Generation of spherical aberration with axially translating phase plates via extrinsic aberration. OPTICS EXPRESS 2014; 22:289-294. [PMID: 24514990 DOI: 10.1364/oe.22.000289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We show that spherical aberration of all orders can be generated as an extrinsic aberration in a system of axially translating plates. Some practical examples are provided. In particular for two phase plates that are 10 mm in diameter it is possible to generate from -10 to 10 waves of fourth-order spherical aberration with an axial displacement of +/- 0.65 mm. We also apply the phenomenon of extrinsic aberration for the generation of a conical wavefront and other non-axially symmetric wavefronts, in other words we propose what can be called a generalized zoom plate.
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Optical quality comparison of conventional and hole-visian implantable collamer lens at different degrees of decentering. Am J Ophthalmol 2013; 156:69-76.e1. [PMID: 23540712 DOI: 10.1016/j.ajo.2013.01.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/25/2013] [Accepted: 01/29/2013] [Indexed: 02/07/2023]
Abstract
PURPOSE To compare the optical quality of implantable Collamer lens (ICL) with and without central hole (Hole ICL and conventional ICL) at different degrees of decentering. DESIGN Experimental laboratory investigation. METHODS Wavefront aberrations of the -3, -6, and -12 diopter (D) V4b and -3, -6, and -12 D V4c ICLs were measured in 3 conditions-centered and decentered 0.3 and 0.6 mm-at 3-mm and 4.5-mm pupils. The root mean square of total higher order aberrations, trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. In addition, point spread function and simulated retinal images of ICLs were calculated from the wavefront aberrations for each ICL and all conditions of decentering at 4.5-mm pupil. RESULTS No statistically significant differences in any Zernike coefficient terms evaluated were found between conventional and Hole ICLs for any ICL powers and pupils evaluated (P > .05). We could not appreciate differences in the point spread function images and in simulated retinal images. Regarding the effect of the ICL decentration, coma aberration increased significantly with ICL decentration (P < .05), although these differences were not visible in the point spread function images and simulated retinal images. The ICL decentration was affected in the same manner on the conventional and Hole ICLs. CONCLUSIONS The outcomes showed good and comparable optical quality of the conventional and Hole ICLs for all ICL powers evaluated. Despite that coma aberration increased with ICL decentering, these values were clinically negligible and did not have a significant effect on the simulated visual performance.
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Madrid-Costa D, Ruiz-Alcocer J, Pérez-Vives C, Ferrer-Blasco T, López-Gil N, Montés-Micó R. Visual simulation through different intraocular lenses using adaptive optics: Effect of tilt and decentration. J Cataract Refract Surg 2012; 38:947-58. [PMID: 22624893 DOI: 10.1016/j.jcrs.2012.01.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/04/2012] [Accepted: 01/05/2012] [Indexed: 01/19/2023]
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Jinabhai A, Neil Charman W, O’Donnell C, Radhakrishnan H. Optical quality for keratoconic eyes with conventional RGP lens and simulated, customised contact lens corrections: a comparison. Ophthalmic Physiol Opt 2012; 32:200-12. [DOI: 10.1111/j.1475-1313.2012.00904.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Acosta E, Sasián J. Phase plates for generation of variable amounts of primary spherical aberration. OPTICS EXPRESS 2011; 19:13171-13178. [PMID: 21747471 DOI: 10.1364/oe.19.013171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We discuss a set of phase plate-pairs for the generation of variable amounts of primary spherical aberration. The surface descriptions of these optical plates are provided, and their aberration-generating properties are verified with real ray-tracing. These plate-pairs are robust in that they allow large tolerances to spacing as well as errors in the relative displacement of the plates. Both primary spherical aberration (r4) and Zernike spherical aberration (6r4- 6r2 + 1) can be generated. The amount of spherical aberration is proportional to the plate-pair displacement and in our example it reaches up to 48 waves (~8 waves Zernike) for a clear aperture of 25 mm.
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Affiliation(s)
- Eva Acosta
- Area de Óptica, Departamento de Física Aplicada, Facultad de Física, Universidad de Santiago de Compostela, Spain.
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Pixton BM, Greivenkamp JE. Spherical aberration gauge for human vision. APPLIED OPTICS 2010; 49:5906-5913. [PMID: 20962957 DOI: 10.1364/ao.49.005906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Spherical aberration affects vision in varying degrees depending on pupil size, accommodation, individual eye characteristics, and interpretations by the brain. We developed a spherical aberration gauge to help evaluate the correction potential of spherical aberration in human vision. Variable aberration levels are achieved with laterally shifted polynomial plates from which a user selects a setting that provides the best vision. The aberration is mapped into the pupil of the eye using a simple telescope. Calibration data are given.
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Affiliation(s)
- Bruce M Pixton
- College of Optical Sciences, University of Arizona, 1630 East University Boulevard, Tucson, Arizona 85721, USA.
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McAlinden C, Moore JE. The change in internal aberrations following myopic corneal laser refractive surgery. Graefes Arch Clin Exp Ophthalmol 2010; 249:775-81. [DOI: 10.1007/s00417-010-1459-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 06/30/2010] [Accepted: 07/07/2010] [Indexed: 10/19/2022] Open
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Abstract
PURPOSE To determine the on-eye effect of spherical and toric contact lens design on higher-order aberrations (HOA). METHODS Thirty eyes (15 subjects) entered a masked, randomized, cross-over study. Each eye was fitted with the spherical and toric lens of the following brands in random order: Acuvue Advance, Biomedics 55, Frequency 55, and SofLens 66. HOAs were measured using the Zywave II Aberrometer over a 6-mm aperture up to fifth order. A linear model accounting for the fixed effect of lens type and random effects of subject and eye was created. Paired t-tests were completed between lens brands within the spherical and toric lenses and between the spherical and toric lens within each brand. Best-corrected visual acuity (VA) was measured and compared. RESULTS No clinically meaningful differences in total HOAs were found between brands or between the spherical and toric lens within a brand. Positive spherical aberration (SA) was reduced by all spherical and toric lenses compared to wearing no lens by 0.07 to 0.23 microm (p < 0.0001). Frequency toric induced the greatest change in SA. The thin-zone design lens (Acuvue Advance for Astigmatism) had a statistically different amount of vertical coma (-0.04 microm) than the three prism-balast toric lenses (0.11 to 0.23 microm; p < 0.0001). SofLens toric had the greatest amount of vertical coma, but better VA than Acuvue Advance for Astigmatism and Frequency toric. With the exception of Acuvue Advance for Astigmatism, toric lenses had greater absolute magnitude of vertical coma than their sphere counterparts (all p < 0.002). No other significant HOA differences were observed. CONCLUSIONS Toric contact lenses with prism-ballast designs demonstrated more vertical coma, but better VA. Positive SA was reduced by spherical and toric contact lenses. The visual quality effect of lens design and material on induced HOAs warrants further investigation.
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Shen J, Thibos LN. Measuring ocular aberrations and image quality in peripheral vision with a clinical wavefront aberrometer. Clin Exp Optom 2009; 92:212-22. [PMID: 19462503 DOI: 10.1111/j.1444-0938.2009.00376.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Clinical aberrometers are accurate, robust instruments for measuring wavefront aberrations for foveal vision, but several practical concerns arise when performing aberrometry of the peripheral field. The purpose of this study was to evaluate these concerns experimentally using a physical eye model. METHODS A physical model eye was constructed to provide a stable test case that resembled a human eye. Aberrations were measured with a commercial Shack-Hartmann aberrometer along lines-of-sight ranging from zero to 45 degrees of eccentricity. Commercial software for wavefront reconstruction and Zernike analysis was adapted for use with elliptical entrance pupils encountered off-axis. RESULTS Pupil dimensions estimated from the array of Shack-Hartmann spots captured by the wavefront sensor followed geometrical optics predictions up to 30 degrees eccentricity. With careful attention to detail, aberration analysis over an elliptical pupil was verified with alternative software. Retinal image quality declined slowly as eccentricity increased due to the eye model's spherical aberration. The total RMS computed from Zernike coefficients overestimated the total RMS computed based on the wavefront error of the elliptical pupil. CONCLUSION Measurement of off-axis wavefront aberrations of a model eye over a restricted range of eccentricities is possible with the COAS clinical wavefront aberrometer and auxiliary lenses to correct astigmatism. When central image quality is good, the off-axis aberrations will have a powerful effect on peripheral image quality. When central image quality is poor, the additional effect of off-axis aberrations will be minor.
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Affiliation(s)
- Jie Shen
- School of Optometry, Indiana University,800 E. Atwater Avenue, Bloomington IN 47405, USA.
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Ojeda-Castañeda J, Landgrave JEA, Gómez-Sarabia CM. Conjugate phase plate use in analysis of the frequency response of imaging systems designed for extended depth of field. APPLIED OPTICS 2008; 47:E99-E105. [PMID: 18670548 DOI: 10.1364/ao.47.000e99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We unveil a relationship between generating a point spread function with a pair of conjugate phase elements and visualizing the modulation transfer function (MTF) of a single phase element for a variable focus error, at a tunable spatial frequency. We show that the defocused MTF of a pair of conjugate phase elements can be expressed as the modulus of the second order ambiguity function of a single phase element. Finally, we propose a tunable wavefront coding technique with a pair of quartic (4th power) conjugate phase elements.
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Lu F, Wu J, Qu J, Wang Q, Xu C, Zhou X, Shen Y, He JC. Association between Offset of the Pupil Center from the Corneal Vertex and Wavefront Aberration. JOURNAL OF OPTOMETRY 2008; 1. [PMCID: PMC3972708 DOI: 10.3921/joptom.2008.8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Purpose To investigate the influence of offsets of the pupil center from the corneal vertex on wavefront aberrations in the anterior cornea and the whole eye. Methods Both right and left eyes of 103 subjects were measured for the wavefront aberrations in the anterior cornea, along with the offset of the pupil center relative to the corneal vertex, using a Humphrey corneal topographer, and for the wavefront aberration in the whole eye using a WASCA wavefront sensor. Correlations of the pupil center offsets with the Zernike aberrations were tested. Results X-axis shift of the pupil center from the corneal vertex was significantly correlated to horizontal coma for both the right (r = 0.54, P<0.0001) and left eyes (r=0.48, P<0.0001) in the cornea, but was weakly correlated to the coma in the whole eye (r=0.17, P=0.04 for OD; and r=0.17, P=0.05 for OS). Significant but weak correlations with the x-axis pupil center shift were also found for several other Zernike aberrations, including the oblique astigmatism, vertical trefoil and secondary astigmatism. Very few Zernike aberrations were significantly correlated to y-axis pupil center shift. Most Zernike aberrations were significantly correlated between the right and left eyes to produce bilateral symmetry in the cornea and the whole eye. Conclusions The results suggest that offset of the pupil center from the corneal vertex plays an important role in determining horizontal coma and few other Zernike aberrations. Factors controlling bilateral symmetry of the wavefront aberrations between the two eyes could make important contributions to wavefront aberrations in the human eye.
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Affiliation(s)
- Fan Lu
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - JiangXiu Wu
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - Jia Qu
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - QinMei Wang
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - ChenChen Xu
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - XiangTian Zhou
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - YeYu Shen
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
| | - Ji C. He
- Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China
- New England College of Optometry, 424, Beacon Street, Boston, MA 02115, USA
- Corresponding author: J.H. Wenzhou Medical College, 82 Xueyuan Road, Wenzhou, Zhejiang 325027. China.
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Rodríguez P, Navarro R, Arines J, Bará S. A New Calibration Set of Phase Plates for Ocular Aberrometers. J Refract Surg 2006; 22:275-84. [PMID: 16602317 DOI: 10.3928/1081-597x-20060301-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To manufacture and test a set of phase plates for the calibration of ocular aberrometers and apply it to the calibration of an ocular laser ray tracing aberrometer. METHODS The set of phase plates is made by a greyscale single-mask photosculpture in photoresist method. Each plate induces a given amount of a particular aberration (Zernike) mode. The set contains two subsets: 1) pure Zernike modes to test the accuracy among different orders (from 3rd to 7th, approximately 0.3 to 0.4 microm); and 2) plates having different amounts of the same mode, 3rd order coma ranging from 0.11 to 0.47 microm. After manufacturing, the plates were tested twice, as a crosscheck, measuring the aberration pattern of each plate with a Mach-Zehnder interferometer and a single-pass Hartmann-Shack wavefront sensor. The set was then applied to the calibration of an ocular double-pass laser ray tracing aberrometer. RESULTS Close agreement was found between the three types of measurement. The maximum difference between Hartmann-Shack and laser ray tracing measurements was 0.032 microm (ie, approximately lambda/20, half of the typical measuring error in human eyes). This permitted detection of a small bias in the ocular laser ray tracing aberrometer. CONCLUSIONS The calibration set may be a powerful tool for the assessment of accuracy and reliability in ocular aberrometry. It discovered a small bias, which is almost impossible to detect when working with human eyes or trial lenses. This type of calibration tool is especially important in clinical environments.
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Acosta E, Bará S. Variable aberration generators using rotated Zernike plates. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2005; 22:1993-6. [PMID: 16211828 DOI: 10.1364/josaa.22.001993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The rotational properties of Zernike polynomials allow for an easy generation of variable amounts of aberration using two rotated phase plates, each one encoding one or several Zernike modes. This effect may be used to build variable aberration generators useful for calibrating different kinds of aberrometer.
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Affiliation(s)
- Eva Acosta
- Area de Optica, Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Compostela, Galiza, Spain.
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24
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Abstract
After outlining what is meant by wavefront aberration, the history of the field of wavefront technology is sketched and methods for measuring ocular wavefront aberration are briefly described. The variations in aberration of the normal eye with the individual and their pupil size, accommodation and age are summarised. Potential contact lens applications are outlined, including the design and on-eye performance of single-vision lenses, lenses for presbyopes and keratoconics, orthokeratology, tear film studies, and the design and performance of customised contact lenses intended to minimise residual lens-eye wavefront error.
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Affiliation(s)
- W N Charman
- Department Optometry and Neuroscience, Faculty of Life Sciences, University of Manchester, P.O. Box 88, Manchester M60 1QD, UK.
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25
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Chowdhury DR, Bhattacharya K, Chakraborty AK, Ghosh R. Polarization-based compensation of astigmatism. APPLIED OPTICS 2004; 43:750-755. [PMID: 14960065 DOI: 10.1364/ao.43.000750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
One approach to aberration compensation of an imaging system is to introduce a suitable phase mask at the aperture plane of an imaging system. We utilize this principle for the compensation of astigmatism. A suitable polarization mask used on the aperture plane together with a polarizer-retarder combination at the input of the imaging system provides the compensating polarization-induced phase steps at different quadrants of the apertures masked by different polarizers. The aberrant phase can be considerably compensated by the proper choice of a polarization mask and suitable selection of the polarization parameters involved. The results presented here bear out our theoretical expectation.
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Affiliation(s)
- Dola Roy Chowdhury
- Department of Applied Physics, Calcutta University, 92, Acharya Prafulla Chandra Road, Calcutta 700009, India.
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26
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Mester U, Dillinger P, Anterist N. Impact of a modified optic design on visual function: clinical comparative study. J Cataract Refract Surg 2003; 29:652-60. [PMID: 12686231 DOI: 10.1016/s0886-3350(02)01983-1] [Citation(s) in RCA: 216] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To determine whether implantation of an intraocular lens (IOL) with a modified anterior surface designed to compensate for the positive spherical aberration of the cornea in eyes of cataract patients results in improved pseudophakic quality of vision. SETTING Department of Ophthalmology, Bundesknappschaft's Hospital, Sulzbach, Germany. METHODS In an intraindividual randomized study of 45 patients with bilateral cataract, an IOL with a modified anterior surface (Tecnis Z9000, Pharmacia) was compared with a biconvex lens with spherical surfaces (SI-40, Allergan). All patients had bilateral cataract surgery; in 1 eye the Z9000 IOL was implanted and in the other, the SI-40 IOL. After 1 and 3 months, the following investigations were performed: assessment of the anterior and posterior segments including IOL decentration and tilt, pupil size, high- and low-contrast visual acuities, photopic and mesopic contrast sensitivities, and wavefront aberration of the cornea and eye. RESULTS Thirty-seven patients were examined at all follow-up visits. Although the eyes with the Z9000 IOL had significantly better best corrected visual acuity after 3 months, the improved quality of vision was more apparent when assessing low-contrast visual acuity and contrast sensitivity. Wavefront measurements revealed no significant spherical aberration in eyes with a Z9000 IOL but significantly positive spherical aberration in eyes with an SI-40 IOL. CONCLUSIONS The clinical results confirm the theoretical preclinical calculations that the spherical aberration of the eye after cataract surgery can be eliminated by modifying the anterior surface of the IOL. The Tecnis Z9000 lens compensates for the positive spherical aberration in older eyes. This leads to a significant improvement, particularly in contrast sensitivity and mesopic visual quality.
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Affiliation(s)
- Ulrich Mester
- Department of Ophthalmology, Bundesknappschaft's Hospital, Sulzbach, Germany.
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27
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Hong X, Thibos LN, Bradley A, Woods RL, Applegate RA. Comparison of monochromatic ocular aberrations measured with an objective cross-cylinder aberroscope and a Shack-Hartmann aberrometer. Optom Vis Sci 2003; 80:15-25. [PMID: 12553540 DOI: 10.1097/00006324-200301000-00004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Repeated measures of wavefront aberrations were taken along the line-of-sight of seven eyes using two instruments: an objective, cross-cylinder aberroscope (OA) and a Shack-Hartmann (SH) aberrometer. Both instruments were implemented on the same optical table to facilitate interleaved measurements on the same eyes under similar experimental conditions. Variability of repeated measures of individual coefficients tended to be much greater for OA data than for SH data. Although Zernike coefficients obtained from a single measurement were generally larger when measured with the OA than with the SH, the averages across five trials were often smaller for the OA. The Zernike coefficients obtained from the two instruments were not significantly correlated. Radial modulation-transfer functions and point-spread functions derived from the two sets of measurements were similar for some subjects, but not all. When average Zernike coefficients were used to determine optical quality, the OA indicated superior optics in some eyes, but the reverse trend was true if Zernike coefficients from individual trials were used. Possible reasons for discrepancies between the OA and SH measurements include difference in sampling density, quality of data images, alignment errors, and temporal fluctuations. Multivariate statistical analysis indicated that the SH aberrometer discriminated between subjects much better than did the objective aberroscope.
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Affiliation(s)
- Xin Hong
- School of Optometry, Indiana University, Bloomington, Indiana 47405-3680, USA
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28
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López-Gil N, Castejón-Mochón JF, Benito A, Marín JM, Lo-a-Foe G, Marin G, Fermigier B, Renard D, Joyeux D, Château N, Artal P. Aberration Generation by Contact Lenses With Aspheric and Asymmetric Surfaces. J Refract Surg 2002; 18:S603-9. [PMID: 12361166 DOI: 10.3928/1081-597x-20020901-21] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE We explored the potential of aberration correction in the human eye by using a new generation of soft contact lenses with aspheric and asymmetric surfaces. METHODS Soft contact lens samples were designed with one asymmetrical surface (front) and one spherical (back) to produce predetermined amounts of desired pure defocus, astigmatism, trefoil, coma, and spherical aberration. Contact lens wavefront aberrations were measured ex vivo using a Fizeau-Tolanski interferometer and compared with the in vivo wavefronts obtained by subtracting the aberrations of the eye with and without the contact lenses. These second set of measurements were obtained using a Shack-Hartmann sensor. RESULTS We found that an aberration-free contact lens sample induced in the eye a small amount of residual aberration. We obtained a good match between the ex vivo and in vivo wavefront measurements for most of the samples of the contact lenses. CONCLUSIONS The aberrations generated by soft contact lenses on the eye were predictable. Rotations and translations of the contact lenses with respect to correct position on the eye were, however, the main limitation for precise correction of the ocular aberrations.
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29
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Castejón-Mochón JF, López-Gil N, Benito A, Artal P. Ocular wave-front aberration statistics in a normal young population. Vision Res 2002; 42:1611-7. [PMID: 12079789 DOI: 10.1016/s0042-6989(02)00085-8] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Monochromatic ocular aberrations in 108 eyes of a normal young population (n=59) were studied. The wave-front aberration were obtained under natural conditions using a near-infrared Shack-Hartmann wave-front sensor. For this population and a 5 mm pupil, more than 99% of the root-mean square wave-front error is contained in the first four orders of a Zernike expansion and about 91% corresponds only to the second order. Comparison of wave-fronts aberrations from right and left eye in 35 subjects, showed a good correlation between most of the second- and third-order terms and a slight (but not clear) tendency for mirror symmetry between eyes.
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Affiliation(s)
- José Francisco Castejón-Mochón
- Laboratorio de Optica, Departamento de Física, Universidad de Murcia, Campus de Espinardo, Edificio C, 30071, Murcia, Spain
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30
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Guirao A, Williams DR, Cox IG. Effect of rotation and translation on the expected benefit of an ideal method to correct the eye's higher-order aberrations. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2001; 18:1003-1015. [PMID: 11336203 DOI: 10.1364/josaa.18.001003] [Citation(s) in RCA: 188] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
An ideal correcting method, such as a customized contact lens, laser refractive surgery, or adaptive optics, that corrects higher-order aberrations as well as defocus and astigmatism could improve vision. The benefit achieved with this ideal method will be limited by decentration. To estimate the significance of this potential limitation we studied the effect on image quality expected when an ideal correcting method translates or rotates with respect to the eye's pupil. Actual wave aberrations were obtained from ten human eyes for a 7.3-mm pupil with a Shack-Hartmann sensor. We computed the residual aberrations that appear as a result of translation or rotation of an otherwise ideal correction. The model is valid for adaptive optics, contact lenses, and phase plates, but it constitutes only a first approximation to the laser refractive surgery case where tissue removal occurs. Calculations suggest that the typical decentrations will reduce only slightly the optical benefits expected from an ideal correcting method. For typical decentrations the ideal correcting method offers a benefit in modulation 2-4 times higher (1.5-2 times in white light) than with a standard correction of defocus and astigmatism. We obtained analytical expressions that show the impact of translation and rotation on individual Zernike terms. These calculations also reveal which aberrations are most beneficial to correct. We provided practical rules to implement a selective correction depending on the amount of decentration. An experimental study was performed with an aberrated artificial eye corrected with an adaptive optics system, validating the theoretical predictions. The results in a keratoconic subject, also corrected with adaptive optics, showed that important benefits are obtained despite decentrations in highly aberrated eyes.
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Affiliation(s)
- A Guirao
- Laboratorio de Optica, Dept. de Física, Universidad de Murcia, Spain.
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31
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Bará S, Mancebo T, Moreno-Barriuso E. Positioning tolerances for phase plates compensating aberrations of the human eye. APPLIED OPTICS 2000; 39:3413-3420. [PMID: 18349911 DOI: 10.1364/ao.39.003413] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The positioning tolerances for phase plates used to compensate human eye aberrations are analyzed. Lateral displacements, in-plane rotations, and axial translations are considered, describing analytic and numerical procedures to compute the maximum degree of compensation achievable in each case. The compensation loss is found to be dependent both on the kind and the amount of misalignment and on the particular composition of the aberration pattern of each subject in terms of Zernike polynomials. We applied these procedures to a set of human eye aberrations measured with the laser ray-tracing method. The general trend of results suggests that lateral positioning, followed by angular positioning, are the key factors affecting compensation performance in practical setups, whereas axial positioning has far less stringent requirements.
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Affiliation(s)
- S Bará
- Area de Optica, Facultade de Física, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia, Spain.
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32
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Navarro R, Moreno-Barriuso E, Bará S, Mancebo T. Phase plates for wave-aberration compensation in the human eye. OPTICS LETTERS 2000; 25:236-8. [PMID: 18059840 DOI: 10.1364/ol.25.000236] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We present a method for manufacturing phase plates to compensate for the wave aberration in the human eye. The wave aberration of the eye is measured in vivo by a new laser ray-tracing method and then compensated for by a phase plate placed in front of the eye. This plate is made from a gray-level single-mask photosculpture in photoresist. Two experiments were carried out, first with an artificial eye and then with a human eye: 80% compensation for the wave aberration was achieved in both cases.
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33
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Barton IM, Dixit SN, Summers LJ, Avicola K, Wilhelmsen J. Diffractive Alvarez lens. OPTICS LETTERS 2000; 25:1-3. [PMID: 18059762 DOI: 10.1364/ol.25.000001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A diffractive Alvarez lens is demonstrated that consists of two separate phase plates, each having complementary 16-level surface-relief profiles that contain cubic phase delays. Translation of these two components in the plane of the phase plates is shown to produce a variable astigmatic focus. Both spherical and cylindrical phase profiles are demonstrated with good accuracy, and the discrete surface-relief features are shown to cause less than lambda/10 wave-front aberration in the transmitted wave front over a 40 mm x 80 mm region.
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34
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Calver RI, Cox MJ, Elliott DB. Effect of aging on the monochromatic aberrations of the human eye. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 1999; 16:2069-78. [PMID: 10474888 DOI: 10.1364/josaa.16.002069] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We measured the contrast sensitivity (CS) of a group of older subjects through natural pupils and compared the results with those from a group of younger subjects. We also measured each subject's monochromatic ocular wave-front aberrations using a crossed-cylinder aberroscope and calculated their modulation transfer functions (MTF's) and root-mean-squared (RMS) wave-front aberrations for fixed pupil diameters of 4 mm and 6 mm and for a natural pupil diameter. The CS at a natural pupil diameter and the MTF computed for a fixed pupil diameter were found to be significantly poorer for the older group than for the younger group. However, the older group showed very similar MTF's and significantly smaller RMS wave-front aberrations compared with the younger group at their natural pupil diameters, owing to the effects of age-related miosis. These results suggest that although monochromatic ocular wave-front aberrations for a given pupil size increase with age, the reduction in CS with age is not due to this increase.
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Affiliation(s)
- R I Calver
- Department of Optometry, University of Bradford, West Yorkshire, United Kingdom.
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35
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López-Gil N, Howland HC. Measurement of the eye's near infrared wave-front aberration using the objective crossed-cylinder aberroscope technique. Vision Res 1999; 39:2031-7. [PMID: 10343787 DOI: 10.1016/s0042-6989(98)00315-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We used the crossed-cylinder aberroscope technique to obtain the near infrared (784 nm) wave-front aberration of the human eye. We compared the results with those obtained under the same conditions using red light (633 nm). Other than the greater retinal scattering of the near infrared light, third- and fourth-order wave-front aberrations are similar in both wavelengths. Values of the calculated near infrared point spread function show a typical half-height width of around 2 arcmin, which is in good agreement with previous work.
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Affiliation(s)
- N López-Gil
- Section of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
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