Spectacle Lenses Research Articles

Vision Correction Habits After COVID-19 Onset in Spectacle and Contact Lens Wearers.

To determine how vision correction habits changed after the 2019 coronavirus disease (COVID-19) pandemic onset. Participants reported vision correction habits, refractive error, screen time, mask wearing time, and dry eye symptoms since the COVID-19 pandemic onset through email survey. A total of 133 participants completed the survey. Worsening dry eye symptoms were associated with increased screen time ( P =0.04). Hours per day of spectacle wear increased by approximately 1 hr ( P =0.001) and was associated with increased screen time ( P =0.002). Worsening dry eye symptoms were associated with increased days per week of spectacle wear ( P =0.02). Participants wore contact lenses about one day per week less than before the pandemic ( P =0.0001). Increased mask wearing time was associated with increased days per week of contact lens wear ( P =0.03). After pandemic onset, hours per day of spectacle wear increased, and days per week of contact lens wear decreased. Increases in hourly spectacle wear were associated with increased screen time, whereas increased daily contact lens wear was associated with increased mask wear time, suggesting that spectacles may be preferred for screen time activities and contact lenses for mask wear.

Virtual Reality Improves Functional Use of Vision in Persons With Albinism

A number of technology-based low-vision aids have been tested and reported in the literature. Virtual reality (VR) assistive devices permit virtually limitless personalized customization of image qualities to meet the needs of each individual with low vision who is reading, using apps, or viewing videos on a computer screen. This study was aimed at evaluating visual acuity in a fully integrated, high-resolution VR-based environment. Twenty individuals with albinism (12 women and 8 men) were recruited in four cohorts, each of which was evaluated in sessions that were 6 months long. The participants were trained and tested with either an Oculus Quest VR headset or an Oculus Quest 2 VR headset, depending on their cohort membership. Two tests for visual acuity, using the Snellen chart and the logarithm of the minimum angle of resolution (LogMAR) chart, were administered to each participant at baseline using clinical protocols and at months 1 and 6 in VR with the Snellen and LogMAR charts presented at appropriate virtual distances. For both the Snellen and LogMAR tests, visual acuity was significantly better in VR at months 1 and 6 than at baseline when the participants were tested with or without corrective lenses. All participants agreed that VR could be useful for people with low vision. VR shows great promise for improving employment options for individuals with low vision.

Refractive extended depth-of-focus lens design based on periodic power profile for presbyopia correction.

Limitations of existing diffractive multifocal designs for presbyopia correction include discrete foci and photic phenomena such as halos and glare. This study aimed to explore a methodology for developing refractive extended depth-of-focus (EDoF) lenses based on a periodic power profile. The proposed design technique employed an optical power profile that periodically alternated between far, intermediate and near distances across the pupil radius. To evaluate the lens designs, optical bench testing was conducted. The impact on visual performance was assessed using a spatial light modulator-based adaptive optics vision simulator in human subjects. Additionally, the effects of pupil size change and lens decentration on retinal image quality were examined. A comparative performance analysis was carried out against a typical diffractive trifocal design and a monofocal lens. The proposed design method was found to be effective in uniformly distributing light energy across all object distances within the desired depth of focus (DoF). While trade-offs between overall image quality and DoF still exist, the EDoF lens design, when tested in human subjects, provided a continuous DoF spanning over 2.25 D. The results also revealed that the EDoF design had a slightly higher dependence on changes in pupil size and lens decentration than the diffractive trifocal design. The proposed design method showed significant potential as an approach for developing refractive EDoF ophthalmic lenses. These lenses offer a continuous DoF but are slightly more susceptible to variations in pupil size and decentration compared with the diffractive trifocal design.

Effectiveness of toric soft contact lenses for vision correction in patients with different degrees of astigmatism: a real-world study.

To assess the visual correction of patients with different degrees of astigmatism with toric soft contact lenses (TSC). It was a real-world study with prospective and single-arm design. A total of 384 patients with astigmatism who came for TSC fitting and alignment from November 2022 to January 2023 were included. According to the difference in astigmatism, patients were divided into groups A (cylinder degree: -0.75 to -0.50 D), B (cylinder degree: -1.75 to -1.00 D) and C (cylinder degree ≤ -2.00 D), and followed up on the day of wear, 1wk, 1 and 3mo, mainly to observe visual acuity, refraction, lens fit, visual quality and comfort at 1wk after wear. The visual acuity success rate and the overall success rate of the fitting were evaluation indicators (taking into account the four dimensions of visual acuity, fitting, quality of vision and comfort). The visual acuity success rate was calculated by taking "corrected visual acuity with contact lenses is no less than 1 line or better than best spectacle-corrected visual acuity" (i.e. corrected visual acuity with contact lenses is 1 line below, equal to, one line above or more than best spectacle-corrected visual acuity) as the criterion for visual success, and the the overall success rate of the fitting was calculated by using the comprehensive indicators (visual acuity, fit, visual quality, comfort) to meet certain conditions as the judgment criteria for successful fitting. After 1wk of wearing TSC, the visual acuity success rates of patients were 100% (207/207), 98.58% (139/141) and 97.22% (35/36) in the three groups, respectively, with residual cylinder closed to 0. The acceptability of the lens fitting was over 95%; the incidence of adverse visual symptoms was within 10% and the comfort acceptability was over 97%. The overall success rate of fitting for patients with high, medium and low astigmatism was 93.72% (194/207), 90.78% (128/141) and 88.89% (32/36), respectively. TSC (model: G&G POP·CT) are effective in correcting astigmatism in patients with different degrees of astigmatism.

Cost-Effectiveness Analysis of Myopia Progression Interventions in Children

Several interventions exist for treating myopia progression in children. While these interventions' efficacy has been studied, their cost-effectiveness remains unknown and has not been compared. To determine cost-effective options for controlling myopia progression in children. In this cost-effectiveness analysis, a Markov model was designed to compare the cost-effectiveness of interventions for controlling myopia progression over 5 years from a societal perspective in a simulated hypothetical cohort of patients aged 10 years with myopia. Myopia interventions considered included atropine eye drops, 0.05% and 0.01%, defocus incorporated multiple segment spectacles, outdoor activity, soft contact lenses (daily disposable and multifocal), rigid gas-permeable contact lenses, progressive addition lenses, bifocal spectacle lenses, orthokeratology, highly aspherical lenslets (HALs), and red light therapy; all interventions were compared with single-vision lenses. Deterministic and probabilistic sensitivity analysis determined the association of model uncertainties with the cost-effectiveness. Costs were obtained from the charges of the Hospital Authority of Hong Kong and The Chinese University of Hong Kong Eye Center. The mean costs (in US dollars) per child included the cost of hospital visits, medications, and optical lenses. The outcomes of effectiveness were the annual spherical equivalent refraction (SER) and axial length (AL) reductions. Incremental cost-effectiveness ratios (ICERs) were calculated for each strategy relative to single-vision lenses over a time horizon of 5 years. Outdoor activity, atropine (0.05%), red light therapy, HALs, and orthokeratology were cost-effective. The ICER of atropine, 0.05%, was US $220/SER reduction; red light therapy, US $846/SER reduction; and HALs, US $448/SER reduction. Outdoor activity yielded a savings of US $5/SER reduction and US $8/AL reduction. Orthokeratology resulted in an ICER of US $2376/AL reduction. These findings suggest that atropine eye drops, 0.05%, and outdoor activity are cost-effective for controlling myopia progression in children. Though more expensive, red light therapy, HALs, and orthokeratology may also be cost-effective. The use of these interventions may help to control myopia in a cost-effective way.

Characteristics associated with blindness or visual impairment within the adolescent demographic: a national cohort analysis

BackgroundPsychosocial metrics associated with self-reported blindness or visual impairment for adolescents in the National Survey of Drug Use and Health (NSDUH) have not been fully characterized. This retrospective cohort analysis of the latest NSDUH aimed to determine novel characteristics associated with self-reported visual loss among adolescents in the United States. MethodsData from the NSDUH2020, a publicly available, federally validated database, were analyzed. Self-reported severe visual impairment or blindness was defined as being truly blind or having serious difficulty seeing even when wearing corrective lenses (s-rSVI). Inclusion criteria were all cases of s-rSVI in adolescents aged 12-17 years. NSDUH weights were used to accommodate complex survey design, nonresponse rates, and population variance. Weighted percentages, asymptotic two-sided Rao-Scott χ2 analyses, and multivariable binary logistic regression were performed. Statistical significance was considered reached at P < 0.05. ResultsA total of 5,667 adolescents aged 12-17 years were surveyed, and s-rSVI occurred in 236 cases (weighted percentage, 3.48%). Within our final risk model, characteristics associated with enhanced odds of s-rSVI based on multivariable logistic regression analysis were female sex, Asian and Latino race/ethnicity (relative to non-Hispanic White), and self-reported serious difficulty hearing and concentrating (all P < 0.05). ConclusionsThis national retrospective cohort analysis highlights risk factors associated with s-rSVI for adolescents within the 2020 NSDUH. Clinicians and policymakers should consider at-risk demographics for s-rSVI during development and enhancement of screening programs, population health initiatives, and healthcare policy issues.

Epidemio-clinical Aspects of Presbyopia at the University Hospital of Bouake

Aim of this study was to contribute towards a better understanding of presbyopia in the subject, with a view to improving its management. Materials and methods: This was a descriptive and analytical retrospective study of the medical records of patients who were received and followed up in the ophthalmology department of the CHU de Bouaké for presbyopia. It took place from January 1, 2013, to December 31, 2017, a period of 5 years. Results: The prevalence was 09.16%. %. The mean age of patients was 51.62 years with extremes of 40 and 86 years. Females predominated (55.61%), with a sex ratio of 0.8. Craftsmen were the most represented socio-professional group (30.49%). Of the total number of patients seen, 34.98% were already wearing corrective lenses. The age of first presbyopia correction was 50.39 years, with extremes of 40 and 82 years for males. For women, it was 51.49 years, with extremes of 40 and 86 years (Table 3). For the 637 male patients, the mean addition value for near vision was 2.02 diopters, with extremes of 1.00 and 5.00 diopters. For the 798 female patients, it was 2.11 diopters, with extremes of 0.75 and 7.50 diopters (Table 4). Presbyopia was isolated in 5.64% of patients.

Influence and Outcome of the COVID-19 Pandemic on Digital Eye Strain in Children

Abstract: The term "digital eye strain" (DES) refers to a group of visual and ocular problems brought on by extended usage of digital electronic gadgets. Dry eyes, itchiness, a feeling of a foreign body, watering, blurred vision, and headaches are its hallmarks. Eye strain can also cause non-ocular symptoms such a stiff neck, generalised weariness, headaches, and backaches. In the years before COVID-19, a varying incidence of 5 to 65% has been recorded. Outdoor activities were limited for all age groups due to lockdown regulations during the pandemic, and digital learning took over for nearly two years. The prevalence of DES increased to 50–60% in children alone, but the symptoms also widened to encompass recently developed esotropia and vergence abnormalities. One of the most important eye health issues is myopia. Following proper ergonomics, such as reducing average daily screen time, frequent blinking, better lighting, minimising glare, taking regular breaks from the screen, occasionally shifting focus to a distant object, and adhering to the 20-20-20 rule can help manage DES. High-resolution screens, built-in antireflective coating, matte-finished glass, edge-to-edge displays, and image-smoothing visual effects are examples of innovations in this area. The recommendations for optimising digital screens, cutting-edge technology for spectacle lenses, and built-in filters to enhance visual comfort should be the focus of further research. Our understanding of how to approach DES from an etiological standpoint needs to change in order to investigate tailored remedies. The purpose of this review article is to understand the pathophysiology of various manifestations, risk factors that predispose to them, different types of treatment choices, as well as evolving trends in DES prevalence following COVID-19

Myopia management -A survey of optometrists and ophthalmologists in Israel.

Myopia management is practiced by ophthalmologists and optometrists. This study evaluated the approach and standard of myopia management among eye-care practitioners (ECPs) in Israel. The findings may ultimately affect the quality of care. A questionnaire was sent to 954 optometrists and 365 ophthalmologists, including demographic questions; whether they owned any devices to monitor myopia progression; the lowest progression they considered significant; various questions pertaining to myopia management and treatment methods. Responses from 135 optometrists and 126 ophthalmologists were collected, the majority practicing more than five years; 94% of optometrists, and 64% of ophthalmologists. Around 53% of optometrists and 27% of the ophthalmologists proclaimed to practice myopia management. ECPs primary parameters influencing risk assessment for progression were age, genetic background and history of progression. Time outdoors, during daylight hours, is advised by ophthalmologists (97%) and optometrists (78%). Limiting screentime is encouraged by 87% of ophthalmologists and 69% of optometrists. Myopia progression of 0.50D-0.75D after six months is regarded to require intervention by 93% of ophthalmologists and 83% of optometrists. Optometrists selected multiple myopia management treatments, primarily optical (ophthalmic myopia management lenses 40%, multifocal ophthalmic lenses 24%, peripheral blur contact lenses 38%, orthokeratology 11%), while 95% of ophthalmologists chose atropine and only 3-11% selected any additional treatments to consider. This study highlighted ECPs' agreement on the principles, importance of, and timeline of intervention with myopia management. The disconnect between the two professions lies in management methods. Genuine dialogue and co-management should be encouraged for maximum implementation, benefit and effectiveness of available patient treatments.

CPD: Myopia management update part 2

Following on from their recent article Myopia management with spectacle lenses – an update (Optician July 28, 2023) – Peter Black and Tina Arbon Black explore myopia evidence, new management options and some of the standards of practice issues that surround myopia management

Visual performance of new affordable and auto-adherent lenses for presbyopia correction.

Presbyopia is a visual condition that affects all of us, evolving with time, reducing the range of accommodation and the ability to work at near. Reading glasses, bifocals or multifocal lenses are the most common solutions. In this work, we demonstrate the near visual performance of new elastomeric auto-adherent lenses developed for the correction of presbyopia. Visual acuity and contrast sensitivity were measured in 10 presbyopic subjects. The results showed that wearing either conventional trial ophthalmic lenses or the new elastomeric lenses provided similar visual quality. These elastomeric lenses can be placed in, or removed from the distance-vision spectacles of the wearers, providing an affordable solution for correcting presbyopia at its clinical onset, which might be especially useful in subjects with different refractive error in each eye and for those with astigmatism.

Preserving polarization maintaining photons for enhanced contrast imaging of the retina.

The purpose of this study is to demonstrate the feasibility of using polarization maintaining photons for enhanced contrast imaging of the retina. Orthogonal-polarization control has been frequently used in conventional fundus imaging systems to minimize reflection artifacts. However, the orthogonal-polarization configuration also rejects the directly reflected photons, which preserve the polarization condition of incident light, from the superficial layer of the fundus, i.e., the retina, and thus reduce the contrast of retinal imaging. We report here a portable fundus camera which can simultaneously perform orthogonal-polarization control to reject back-reflected light from the ophthalmic lens and parallel-polarization control to preserve the backscattered light from the retina which partially maintains the polarization state of the incoming light. This portable device utilizes miniaturized indirect ophthalmoscopy illumination to achieve non-mydriatic imaging, with a snapshot field of view of 101° eye-angle (67° visual-angle). Comparative analysis of retinal images acquired with a traditional orthogonal-polarization fundus camera from both normal and diseased eyes was conducted to validate the usefulness of the proposed design. The parallel-polarization control for enhanced contrast in high dynamic range imaging has also been validated.

Preventing the Progression of Myopia in Children-A Review of the Past Decade.

The growing incidence of myopia worldwide justifies the search for efficient methods of myopia prevention. Numerous pharmacological, optical, and lifestyle measures have already been utilized, but there remains a need to explore more practical and predictable methods for myopia control. This paper presents a review of the most recent studies on the prevention of myopia progression using defocus-incorporated multiple-segment spectacle lenses (DIMSsl), repeated low-level red-light (RLRL) therapy, and a combination of low-dose atropine (0.01%) with orthokeratology lenses.

Clinical Evaluation of MyoCare in Europe (CEME): study protocol for a prospective, multicenter, randomized, double-blinded, and controlled clinical trial

BackgroundMyopia prevalence has been increasing in the last decades, and its pathological consequences, including myopic maculopathy and high myopia-associated optic neuropathy, are now one of the most common causes of visual impairment. It is estimated that by 2050, more than 50% of Europeans and Americans will be myopes, which is alarming due to the high morbidity of myopes over − 6.00D. Once myopia has appeared, there are different options with scientific evidence to try to slow the axial length growth. Ophthalmic lenses are the less invasive treatment to control myopia, and there is evidence about the efficacy of different designs, mainly in the Asiatic population. However, new designs have been launched, and it is not known if efficacy is the same between Asiatic and European subjects. Thus, we have set up a randomized, controlled, double-blind, and multicenter trial to investigate the efficacy of a new design of ophthalmic lenses for myopia control in European children.MethodsA 2-year prospective, multicenter, randomized controlled, and double-blind clinical trial is used to investigate the efficacy of a new design of ophthalmic lenses to slow the progression of myopia. Three hundred children aged from 6 to 13 years old will be recruited and randomly assigned to a study or control group. The study group will be composed of 150 children wearing MyoCare while the control group will be composed of 150 children wearing Clearview. The inclusion criteria will be myopia with a spherical equivalent between − 0.75D and − 5.00D, astigmatism < 1.50D, and anisometropia < 1.00D and having a historical evolution of at least − 0.50 The primary outcome is to compare the mean annual progression of the spherical equivalent between both groups. The secondary outcomes are axial length, choroidal thickness, phorias, and accommodative status of both groups.DiscussionThis study will be the first randomized and controlled clinical trial in European children with spectacle lenses based on simultaneous competing defocus. The results will shed light on the clinical evidence of spectacle lenses relying on this new design for the management of myopia with results of efficacy in the non-Asiatic population.Trial registrationEU Clinical Trials Register (EudraCT) 2022–001696. Registered on 27 April 2022. ClinicalTrials.gov NCT05919654. Registered on 26 June 2023.

Effect of presbyopic correction lens on humphrey visual field testing in patients with multifocal intraocular lens.

Most previous studies on the effects of multifocal intraocular lenses (MIOL) on Humphrey visual field (HVF) used presbyopic corrective lens (PC). There has been insufficient data from patients with MIOL performing HVF with and without PC. This study aimed to determine the effect of PC on HVF testing in patients with MIOL. This was a prospective, comparative crossover study at the Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Mahidol University between June 2015 and July 2018. Early-stage glaucomatous and non-glaucomatous pseudophakic patients with 2 models of MIOL completed HVF testing with and without PC. Mean deviation (MD), pattern standard deviation (PSD), and reliability indices (fixation losses, false positives, and false negatives) were compared. Ninety-four eyes of 59 patients were enrolled. After excluding patients with confirmed unreliable visual field, 82 eyes of 51 patients (male, 22; female, 29) with a mean age of 65.4 years were included in the study. Forty-nine eyes were non-glaucoma and 33 eyes were early-stage glaucoma. Forty-four eyes received TECNIS ZM900 and 38 eyes received Acrysof IQ ReSTOR SN6AD1. The overall MD standard deviation was -3.5 (2.1) with PC and -3.1 (2.1) without PC (P = .01). The overall PSD standard deviation was 2.8 (1.5) with PC and 2.7 (1.5) without PC (P = .93). The reliability indices were not statistically significantly different with and without PC. There was a good intraclass correlation (ICC) of MD (ICC = 0.87) and PSD (ICC = 0.88) with and without PC. Eyes with TECNIS ZM 900 had significantly better MD when performing HVF without PC (mean difference -0.7, P < .01), but not with Acrysof IQ ReSTOR SN6AD1 (mean difference -0.1, P = .74). Pseudophakic eyes with MIOL may not require PC during HVF testing regardless of the MIOL model. Although eyes with TECNIS ZM900 performed HVF without PC resulted in a significantly better MD value compared with PC, the difference was not clinically significant.

Correlation Analysis of Surface and Physical Properties of Ophthalmic Lenses Containing Nanoparticles.

Since contact lenses directly contact the cornea, the surface roughness of the lens may cause various side effects. In addition, gold nanoparticles can realize a variety of colors and characteristics depending on their shape and size. In this study, the surface roughness of tinted lenses containing gold nanoparticles of various sizes was analyzed using atomic force microscopy (AFM) at aspect ratio(surface to volume ratio) ranging from 1:1 to 1:10. The characteristics of the lenses were then confirmed. As a result, tinted lenses with different colors depending on the size of the gold nanoparticles were manufactured. The surface roughness of the lens decreased with increasing size of the gold nanoparticles. However, at aspect ratio of 1:10, increase in surface roughness was observed. In addition, it was confirmed that the wettability and antibacterial properties of the lens had the same effect according to the average surface roughness value. Therefore, it was confirmed that the addition of gold nanoparticles reduced the surface roughness of the lens, which had a great effect on properties such as wettability and antimicrobial properties of the lens. The produced copolymer controls the surface roughness of the lens, and thus it is judged that it can be used as a material for various ophthalmology applications.

Designing a vision of the future

Andrew McCarthy-McClean explores how ophthalmic lens companies are using AI in research and development

Toric Intraocular Lens versus Peripheral Corneal Relaxing Incisions for Astigmatism between 0.75 and 2.5 Diopters: 5-Years Outcomes

Purpose To compare 5-year outcomes of toric intraocular lens (tIOL) or peripheral corneal relaxing incision (PCRI) for correction of keratometric astigmatism (KA) between 0.75 and 2.5 diopters (D). Methods Setting: University Hospital. Design: Randomized clinical trial. Eighty eyes (80 participants) received either tIOL or PCRI. Patients were assessed preoperatively, 1-month, 1, and 5 years. Primary outcomes were uncorrected (UDVA) and best-corrected distance logMAR visual acuity (CDVA). Secondary outcomes were a manifest refractive sphere, refractive astigmatism (Ra), spherical equivalent (SEQ), KA & mean keratometry (KM), and Quality-of-Life Impact of Refractive Correction (QIRC) scores. Results There was no difference between the two groups in UDVA, CDVA, refractive sphere, KM, RA, and SEQ. KA reduced after 1 month in the PCRI group and remained stable until 5 years. From 1 to 5 years, the number of eyes with distance emmetropia (within ±0.13D) changed from 59% (20/34 eyes) to 32% (6/19 eyes) for tIOLs and from 43% (15/36 eyes) to 20% (4/21 eyes) for PCRIs with 32% (6/19 eyes) and 20% (4/21 eyes) showing >0.5D change in SEQ at 5-years respectively. Compared to 1-year, Ra significantly increased at 5 years in both groups with no difference between the groups. Mean overall QIRC scores were not different between the groups (tIOL: 49.88 ± 7.47; PCRI: 52.09 ± 7.02; p = .18). Conclusions Although there was no difference between the overall visual and vision-related quality of life outcomes between tIOLs and PCRIs, an increase in refractive astigmatism and reduction in distance emmetropia with time was noted in both groups.

Толщина хориоидеи у детей с прогрессирующей миопией и влияние на нее ношения очков с высокоасферичными микролинзами в течение 12 месяцев

Purpose. Due to the importance of choroid in the development of myopia, this study examined choroid thickness (CT) in children with progressive myopia and the effect of Stellest™ on the CT after 1 year of wear. Methods. A total of 50 children with myopia from –0.75D to –4.75D aged 7 to 13 years were enrolled. CT beneath the fovea, 1.5 mm and 3 mm temporal, nasal, superior and inferior to the fovea was measured by OCT at baseline and 1 month and 1 year after the treatment. The relationship between the degree of myopia, axial length, and choroidal thickness was determined. Results. Prior to treatment there was a significant negative relationship between CT, myopia degree (r = –0.63) and axial length (AL) (r = –0.53). Wearing Stellest™ induced significant choroidal thickening in the first month of treatment by 17.47±13.14 μm in all zones in 82.1 % of eyes. CT did not change in 17.9 % of eyes. Myopia has progressed in those children during 1 year. Mean annual progression gradient has decreased from –1.03±0.58D to –0.03 ±0.40D, growth of AL has decreased from 0.37±0.22 mm to 0.06±0.19 mm after 1 year. Myopia has increased by ≥ 0.25D in 27.5 % of eyes, AL has increased by ≥ 0.1mm in 29.3 % of eyes. After 1 year, a hyperopic shift of refraction within 0.5D was observed in 27.3 % of eyes and reduction in AL in 27 % of eyes, this was combined with an increase in CT by 21.24±17.61μm. After 1 year the choroid was significantly thicker in comparison with the beginning of the study. In those patients where AL has increased ≥0.1mm, CT has decreased by 12.44±8.17μm. Conclusion: Choroid thickness decreases during myopia development. Spectacle lenses with aspherical lenslets significantly increase choroidal thickness after 1 month and 1year of wear. Choroid thickness might work as a predictor of the effectiveness of myopia treatment. Key words: myopia control; myopic defocus; choroid thickness; spectacle lenses with aspherical lenslets.

Liquid-phase Integrated 3d Printed Biological Lenses for Lamellar Corneal Substitute.

Compared to traditional biological lenses that are used to correct and repair optical systems, such as contact lenses, vision correction surgery, and corneal and lens replacement, three-dimensional (3D) printed biological lenses can be customized according to user needs. However, the layer-by-layer principle of 3D printing leads to a staircase effect, which cannot meet the critical requirements of surface quality during the manufacturing process of biological lens, particularly with soft materials. Here, a liquid-phase printing strategy and a surface tension-dependent (STD) post-processing method are proposed that use the surface tension of the liquid to reconstruct the air-liquid interface. This eliminates the staircase effect caused by the stacking of units during 3D printing. The coordinates of integrated printing enable high-accuracy shape control of soft materials. Based on this method, using a typical biological lenses as an example, the surface quality of printed lamellar corneal substitute (LCS) was improved from ±20.0μm to ±0.2μm, and the thickness feature size was reduced from ±500μm to ±150μm. It can be used to fit the curvature and thickness of the human cornea. The visible light transmittance reaches the level of the natural cornea (∼85%) and is biocompatible. Liquid-phase 3D printed biological lenses performed better in vivo in rabbit eyes than the molded group. This method can potentially boost research on artificial biological lens printing technology and has good potential for use in future clinical applications. This article is protected by copyright. All rights reserved.