1
|
Pourreza Ghoushchi V, Mompeán J, Prieto PM, Artal P. Contrast sensitivity is resilient to induced fast periodic defocus oscillations. BIOMEDICAL OPTICS EXPRESS 2024; 15:3848-3858. [PMID: 38867768 PMCID: PMC11166443 DOI: 10.1364/boe.521340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 06/14/2024]
Abstract
This study investigates the potential effects of periodic defocus oscillations on contrast sensitivity. Sinusoidal fluctuations at 5, 15, and 25 Hz, with defocus peak-to-valley values ranging from 0.15 to 3 D, were induced by means of a focus-tunable lens after calibrating its dynamic behavior. Monocular contrast sensitivity was measured on five young emmetropic subjects. The experimental data shows that contrast sensitivity loss due to defocus fluctuations is low for a wide range of frequencies and amplitudes. Only for the more severe case studied (25 Hz, ± 1.5 D) contrast threshold showed a clear increase in most subjects. Qualitative comparison of the empirical data with a simulation of modulation loss due to time integration of defocused retinal point spread functions, suggests a short integration time by the eye for defocus blur, around or even below a hundredth of a second.
Collapse
Affiliation(s)
- Vahid Pourreza Ghoushchi
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Edificio 34), E-30100 Murcia, Spain
| | - Juan Mompeán
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Edificio 34), E-30100 Murcia, Spain
| | - Pedro M. Prieto
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Edificio 34), E-30100 Murcia, Spain
| | - Pablo Artal
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Edificio 34), E-30100 Murcia, Spain
| |
Collapse
|
2
|
Soomro SR, Sager S, Paniagua-Diaz AM, Prieto PM, Artal P. Head-mounted adaptive optics visual simulator. BIOMEDICAL OPTICS EXPRESS 2024; 15:608-623. [PMID: 38404335 PMCID: PMC10890873 DOI: 10.1364/boe.506858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/22/2023] [Accepted: 12/26/2023] [Indexed: 02/27/2024]
Abstract
Adaptive optics visual simulation is a powerful tool for vision testing and evaluation. However, the existing instruments either have fixed tabletop configurations or, being wearable, only offer the correction of defocus. This paper proposes a novel head-mounted adaptive optics visual simulator that can measure and modify complex ocular aberrations in real-time. The prototype is composed of two optical modules, one for the objective assessment of aberrations and the second for wavefront modulation, all of which are integrated into a wearable headset. The device incorporates a microdisplay for stimulus generation, a liquid crystal on silicon (LCoS) spatial light modulator for wavefront manipulation, and a Hartmann-Shack wavefront sensor. Miniature optical components and optical path folding structures, together with in-house 3D printed mounts and housing, were adapted to realize the compact size. The system was calibrated by characterizing and compensating the internal aberrations of the visual relay. The performance of the prototype was analyzed by evaluating the measurement and compensation of low-order and higher-order aberrations induced through trial lenses and phase masks in an artificial eye. The defocus curves for a simulated bifocal diffractive lens were evaluated in real eyes. The results show high accuracy while measuring and compensating for the induced defocus, astigmatism, and higher-order aberrations, whereas the MTF analysis shows post-correction resolution of up to 37.5 cycles/degree (VA 1.25). Moreover, the subjective test results show the defocus curves closely matched to a commercial desktop visual simulator.
Collapse
Affiliation(s)
- Shoaib R. Soomro
- Voptica S.L., Campus de Espinardo (Edificio Pleiades), 30100 Murcia, Spain
- Electronic Engineering Department, Mehran University of Engineering and Technology, Pakistan
| | - Santiago Sager
- Voptica S.L., Campus de Espinardo (Edificio Pleiades), 30100 Murcia, Spain
- Laboratorio de Óptica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100 Murcia, Spain
| | - Alba M. Paniagua-Diaz
- Laboratorio de Óptica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100 Murcia, Spain
| | - Pedro M. Prieto
- Laboratorio de Óptica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100 Murcia, Spain
| | - Pablo Artal
- Laboratorio de Óptica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100 Murcia, Spain
| |
Collapse
|
3
|
Wolffsohn JS, Davies LN, Sheppard AL. New insights in presbyopia: impact of correction strategies. BMJ Open Ophthalmol 2023. [DOI: 10.1136/bmjophth-2022-001122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Presbyopia occurs when the physiologically normal age-related reduction in the eyes focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual’s requirements. Hence, it is more about the impact it has on an individual’s visual ability to function in their environment to maintain their lifestyle than a measured loss of focusing ability. Presbyopia has a significant impact on an individual’s quality of life and emotional state. While a range of amelioration strategies exist, they are often difficult to access in the developing world and prescribing is generally not optimal even in developed countries. This review identified the need for a standardised definition of presbyopia to be adopted. An appropriate battery of tests should be applied in evaluating presbyopic management options and the results of clinical trials should be published (even if unsuccessful) to accelerate the provision of better outcomes for presbyopes.
Collapse
|
4
|
Agarwala R, Lukashova Sanz O, Seitz IP, Reichel FF, Wahl S. Evaluation of a liquid membrane-based tunable lens and a solid-state LIDAR camera feedback system for presbyopia. BIOMEDICAL OPTICS EXPRESS 2022; 13:5849-5859. [PMID: 36733729 PMCID: PMC9872906 DOI: 10.1364/boe.471190] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/27/2022] [Accepted: 08/28/2022] [Indexed: 05/30/2023]
Abstract
Presbyopia is an age-related loss of accommodation ability of the eye which affects individuals in their late 40s or early 50s. Presbyopia reduces the ability of a person to focus on closer objects at will. In this study, we assessed electronically tunable lenses for their aberration properties as well as for their use as correction lenses. The tunable lenses were evaluated in healthy subjects with cycloplegia by measuring visual acuity and contrast sensitivity for their use in presbyopia correction. Furthermore, we have developed and demonstrated the feasibility of a feedback mechanism for the operation of tunable lenses using a portable solid-state LIDAR camera with a processing time of 40 ± 5 ms.
Collapse
Affiliation(s)
- Rajat Agarwala
- Institute for Ophthalmic Research, University of Tuebingen, Elfriede-Aulhorn-Str. 7, Tuebingen, 72076, Germany
| | - Olga Lukashova Sanz
- Institute for Ophthalmic Research, University of Tuebingen, Elfriede-Aulhorn-Str. 7, Tuebingen, 72076, Germany
- Carl Zeiss Vision International GmbH, Turnstr. 27, Aalen, 73430, Germany
| | - Immanuel P. Seitz
- Institute for Ophthalmic Research, University of Tuebingen, Elfriede-Aulhorn-Str. 7, Tuebingen, 72076, Germany
- Carl Zeiss Vision International GmbH, Turnstr. 27, Aalen, 73430, Germany
| | - Felix F. Reichel
- Institute for Ophthalmic Research, University of Tuebingen, Elfriede-Aulhorn-Str. 7, Tuebingen, 72076, Germany
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Siegfried Wahl
- Institute for Ophthalmic Research, University of Tuebingen, Elfriede-Aulhorn-Str. 7, Tuebingen, 72076, Germany
- Carl Zeiss Vision International GmbH, Turnstr. 27, Aalen, 73430, Germany
| |
Collapse
|
5
|
Karkhanis MU, Ghosh C, Banerjee A, Hasan N, Likhite R, Ghosh T, Kim H, Mastrangelo CH. Correcting Presbyopia With Autofocusing Liquid-Lens Eyeglasses. IEEE Trans Biomed Eng 2021; 69:390-400. [PMID: 34232861 DOI: 10.1109/tbme.2021.3094964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Presbyopia, an age-related ocular disorder, is characterized by the loss in the accommodative abilities of the human eye. Conventional methods of correcting presbyopia divide the field of view, thereby resulting in significant vision impairment. We demonstrate the design, assembly and evaluation of autofocusing eyeglasses for restoration of accommodation without dividing the field of view. METHODS The adaptive optics eyeglasses comprise of two variable-focus liquid lenses, a time-of-flight range sensor and low-power, dual microprocessor control electronics, housed within an ergonomic frame. Subject-specific accommodation deficiency models were utilized to demonstrate high-fidelity accommodative correction. The abilities of this system to reduce accommodation deficiency, its power consumption, response time, optical performance and MTF were evaluated. RESULTS Average corrected accommodation deficiencies for 5 subjects ranged from -0.021 D to 0.016 D. Each accommodation correction calculation was performed in ∼67 ms which consumed 4.86 mJ of energy. The optical resolution of the system was 10.5 cycles/degree, and featured a restorative accommodative range of 4.3 D. This system was capable of running for up to 19 hours between charge cycles and weighed ∼132 g. CONCLUSION The design, assembly and performance of an autofocusing eyeglasses system to restore accommodation in presbyopes has been demonstrated. SIGNIFICANCE The new autofocusing eyeglasses system presented in this article has the potential to restore pre-presbyopic levels of accommodation in subjects diagnosed with presbyopia.
Collapse
|
6
|
Aydındoğan G, Kavaklı K, Şahin A, Artal P, Ürey H. Applications of augmented reality in ophthalmology [Invited]. BIOMEDICAL OPTICS EXPRESS 2021; 12:511-538. [PMID: 33659087 PMCID: PMC7899512 DOI: 10.1364/boe.405026] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 05/21/2023]
Abstract
Throughout the last decade, augmented reality (AR) head-mounted displays (HMDs) have gradually become a substantial part of modern life, with increasing applications ranging from gaming and driver assistance to medical training. Owing to the tremendous progress in miniaturized displays, cameras, and sensors, HMDs are now used for the diagnosis, treatment, and follow-up of several eye diseases. In this review, we discuss the current state-of-the-art as well as potential uses of AR in ophthalmology. This review includes the following topics: (i) underlying optical technologies, displays and trackers, holography, and adaptive optics; (ii) accommodation, 3D vision, and related problems such as presbyopia, amblyopia, strabismus, and refractive errors; (iii) AR technologies in lens and corneal disorders, in particular cataract and keratoconus; (iv) AR technologies in retinal disorders including age-related macular degeneration (AMD), glaucoma, color blindness, and vision simulators developed for other types of low-vision patients.
Collapse
Affiliation(s)
- Güneş Aydındoğan
- Koç University, Department of Electrical Engineering and Translational Medicine Research Center (KUTTAM), Istanbul 34450, Turkey
| | - Koray Kavaklı
- Koç University, Department of Electrical Engineering and Translational Medicine Research Center (KUTTAM), Istanbul 34450, Turkey
| | - Afsun Şahin
- Koç University, School of Medicine and Translational Medicine Research Center (KUTTAM), Istanbul 34450, Turkey
| | - Pablo Artal
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain
| | - Hakan Ürey
- Koç University, Department of Electrical Engineering and Translational Medicine Research Center (KUTTAM), Istanbul 34450, Turkey
| |
Collapse
|