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The BVI ISOPURE ® intraocular lens (IOL) (PhysIOL, Liege, Belgium) is a fully refractive, aspherical, monofocal lens based on isofocal technology. Isofocal technology provides cataract patients distance vision quality combined with improved unaided intermediate vision by accentuating the extended depth of field/focus (EDOF) effect whilst inducing minimal photic phenomena., Methods: PubMed, Web of Science, Scopus, and Google Scholar searches were conducted for published research articles featuring the ISOPURE 123 IOL., Results: Excellent uncorrected and corrected binocular distance visual acuity of at least 20/25 can be achieved; uncorrected binocular intermediate vision of 20/25 or better in 81% and 50% at 80 cm and 66 cm, respectively, and 42% binocular near vision of 20/40 or better can be achieved. The defocus curve showed good visual acuity at far and intermediate distances with a depth of focus value of 1.50 D. Photic phenomena are minimal compared to other EDOF IOLs. Excellent contrast sensitivity was maintained compared to a standard monofocal IOL., Conclusion: Studies show that this isofocal optic design IOL provides excellent visual performance for far vision and functional intermediate vision with an increased range of vision with few photic phenomena. This lens is an effective option for providing functional intermediate vision and correcting aphakia., Competing Interests: The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ansari.)

Background: Uncorrected refractive errors contribute enormously to the burden of avoidable visual impairment worldwide. There is a huge disparity in different parts of the globe in context to spectacle coverage for distance vision. This study was undertaken with objectives of determining prevalence of spectacle coverage, unmet needs and associated factors among adults in a rural community of north India., Methods: A community-based cross-sectional study was carried out within selected clusters of Jhajjar district of Haryana. All participants aged > 15 years underwent visual acuity assessment by LogMAR "E" screening chart. Participants with presenting visual acuity < 6/12 in any eye and all current spectacle users underwent detailed ophthalmic examination and refraction. Additional details about spectacles, barriers for their use and willingness to pay for them were collected. Participants with met and unmet need for spectacle use at visual acuity > 6/12 was computed. These are reported as proportions with 95% confidence intervals. Associated factors with unmet need were determined using bivariable and multivariable logistic regression analysis., Results: A total of 6910 participants were examined. The current spectacle use was 7.5% (95% Confidence Interval CI: 6.5, 8.7). The spectacle coverage was found in 33.3% (95% CI: 30.0, 36.7) participants among those in need. The unmet need was found in 10.8% of participants (95% CI: 10.1, 11.6). On multivariable analysis, odds of unmet need was associated with age, gender, level of education and marriage status. The most common barrier for refractive correction was lack of perceived need for refraction and its correction., Conclusion: There is substantial unmet need for distance vision spectacles in this population. It is imperative that multi-component intervention be implemented to improve spectacle coverage in this rural north Indian setting.

Based on the initial movement of falling prey, hunting archerfish select a C-start that turns them right to where their prey is going to land and lends the speed to arrive simultaneously with prey. Our companion study suggested that the information sampled in less than 100 ms also includes the initial height of falling prey. Here, we examine which cues the fish might be using to gauge height so quickly. First, we show that binocular cues are not required: C-starts that either could or could not have used binocular information were equally fast and precise. Next, we explored whether the fish were using simplifying assumptions about the absolute size of their prey or its distance from a structured background. However, experiments with unexpected changes from the standard conditions failed to cause any errors. We then tested the hypothesis that the fish might infer depth from accommodation or from cues related to blurring in the image of their falling prey. However, the fish also determined the height of 'fake flies' correctly, even though their image could never be focused and their combined size and degree of blurring should have misled the fish. Our findings are not compatible with the view that archerfish use a flexible combination of cues. They also do not support the view that height is gauged relative to structures in the vicinity of starting prey. We suggest that these fish use an elaborate analysis of looming to rapidly gauge initial height., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)

Background/purpose: To evaluate the relationship between refractive error and vision-related quality of life in 16-year-old students in Taiwan., Methods: A cross-sectional study was designed for 16-year junior-high-school students in Taiwan. Myopia was defined as a spherical refractive error (SRE) < -0.50 D, hyperopia as SRE > +1.0 D, and emmetropia as SRE -0.5-+1.0 D in the better eye. Vision-related quality of life was assessed using the Taiwan Chinese version of the 25-Item National Eye Institute Visual Functioning Questionnaire., Results: Of the 688 participants, 466 (68%) had myopia and 22 (3%) had hyperopia. In logistic-regression models adjusted for gender, parents' education, family income, and parental refractive error, myopia was an independent risk factor of poorer vision-related quality of life for both near vision (odds ratio 1.73, 95% confidence interval 1.22-2.45) and distance vision (odds ratio 3.11, 95% confidence interval 2.23-4.35). Hyperopia was not associated with near- or distance-vision difficulty., Conclusion: In this study population, myopia was associated with difficulties in near and distance vision compared to emmetropia. Further studies are needed to confirm our findings in other populations., Competing Interests: Conflicts of interest: There is no financial conflict of interest for this study.

Very few visual systems diverge fundamentally from the basic plans of well-studied animal eyes. However, investigating those that do can provide novel insights into visual system function. A particularly unusual system exists in the principal larval eyes of a visually guided aquatic predator, the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dystiscidae). These eyes are characterized by complex layered distal and proximal retinas. We previously reported that their principal eye E2 has a bifocal lens, and previous behavioral experiments suggested that these larvae have a unilateral range-finding mechanism that may involve their bizarre eye organization. In the present study, we expanded our optical measurements and found that: (1) E1 also has a bifocal lens, (2) E1 is best suited for far vision while E2 is best suited for near vision and (3) throughout their typical hunting range, the positions of focused images shift across specific retinal layers. This anatomical and optical organization in principle could support unilateral range finding. Taken together, our findings outline an unusual visual mechanism that is likely to be essential for the extraordinary hunting ability of these larvae., (© 2014. Published by The Company of Biologists Ltd.)