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The global all-ages prevalence of epidemiologically-measured 'functional' presbyopia was estimated at 24.9% in 2015, affecting 1.8 billion people. This prevalence was projected to stabilise at 24.1% in 2030 due to increasing myopia, but to affect more people (2.1 billion) due to population dynamics. Factors affecting the prevalence of presbyopia include age, geographic location, urban versus rural location, sex, and, to a lesser extent, socioeconomic status, literacy and education, health literacy and inequality. Risk factors for early onset of presbyopia included environmental factors, nutrition, near demands, refractive error, accommodative dysfunction, medications, certain health conditions and sleep. Presbyopia was found to impact on quality-of-life, in particular quality of vision, labour force participation, work productivity and financial burden, mental health, social wellbeing and physical health. Current understanding makes it clear that presbyopia is a very common age-related condition that has significant impacts on both patient-reported outcome measures and economics. However, there are complexities in defining presbyopia for epidemiological and impact studies. Standardisation of definitions will assist future synthesis, pattern analysis and sense-making between studies., Competing Interests: Declaration of competing interest Maria Markoulli, Timothy R. Fricke, Anitha Arvind, Kevin D. Frick, Kerryn M. Hart, Mahesh R. Joshi, Himal Kandel, Antonio Filipe Macedo, Dimitra Makrynioti, Neil Retallic, Nery Garcia-Porta and Gauri Shrestha have no declarations of competing interest. James S. Wolffsohn has received grant funding from Alcon and Rayner, is a paid consultant for Alcon, Atia Vision and Bausch + Lomb, and has stock ownership in Wolffsohn Research Ltd., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Recent estimates of global prevalence of uncorrected presbyopia range from 510 to 826 million. There is a shortage of primary data regarding Near Visual Impairment (NVI) magnitude., Methods: Near visual acuity (NVA) and NVI data was collected from over 388,000 people aged 35 or over across 9 countries, within Community Eye Health programmes between January 2022 and June 2023. In Kenya (n = 34,328), dioptric power of required near correction was also recorded, and any association with age, gender or level of NVA was assessed via linear regression model., Results: 146,801 of 388,939 people failed initial near vision screening (37.74%, 95% CI 37.59-37.89%), with significantly higher prevalence of NVI in Sub-Saharan Africa than South Asia. Of those with distance acuity 6/12 or better, 27.97% failed (95% CI 27.81-28.13%) with evidence of difference between genders (p < 0.001): 30.77% of women vs. 24.47% of men. The most commonly required dioptric powers of correction were +2.00D, +2.50D and +3.00D, and required power correlated with age and NVA., Conclusions: NVI remains common among Community Eye Health programme participants aged 35 and over. Data from large scale programmes such as these provide an opportunity to contribute to more accurate epidemiological estimates, and to guide future research, resource planning and intervention, ideally with improved standardisation of testing in the future., (© 2024. The Author(s).)

Background: This study investigated patients' awareness of presbyopia and its management approaches and their preferred methods for near vision correction., Methods: In Saudi Arabia, 785 participants (aged between 35 and 60 years) completed a structured survey online, consisting of hard copies and direct interviews. The survey consisted of twenty-eight items divided into three parts. It was designed to record participants' awareness of and preferences for presbyopia and its refractive corrections. Nonparametric tests and descriptive analyses were conducted to analyse participants' responses., Result: Approximately half of the participants had difficulty with near vision activities, such as reading newspapers or using mobile phones. Among all the participants, 76% were not aware of presbyopia. The prevalence of uncorrected presbyopia was 48% of the 785. The majority (82%) felt that spectacles were acceptable for correction of presbyopia. Most reported that they did not experience social stigma when using reading spectacles (87% of participants). When asked if they were aware of management approaches other than spectacles, 72% responded with not at all. Most participants had no earlier knowledge of the use of multifocal contact lenses or eye drops for presbyopia correction (67% and 82%, respectively). In the present study, some tendencies to use corrective approaches to presbyopia other than spectacles were noted. Finally, participants' age, sex, region, education, and income had a statistically significant impact on essential parts of their responses (p < 0.05)., Conclusion: Presbyopia is a highly prevalent age-related ocular disorder, and a significant percentage of cases are uncorrected due to a lack of awareness or reluctance to wear spectacles. More efficient health education about presbyopia and its corrective alternatives is urgently needed., (© 2024. The Author(s).)

Purpose: The purpose of this study was to explore risk factors for symptomatic presbyopia, defined as near add power ≥1.50 diopters, in patients with glaucoma., Methods: Treated glaucoma (n = 56), untreated glaucoma (n = 21), and control individuals (n = 376), aged 40 to 55 years at first visit, were enrolled in the study, and near add power, retinal thickness, and visual field were examined. The association between near add power and ocular parameters and the odds ratios (ORs) for symptomatic presbyopia were investigated. Survival analysis for symptomatic presbyopia was conducted., Results: Age, astigmatic power, mean deviation, and ganglion cell complex thickness were associated with near add power. The OR for symptomatic presbyopia was significant for age (OR = 1.51), astigmatism (OR = 1.01), mean deviation (OR = 0.72), ganglion cell complex thickness (OR = 0.98), treated and untreated glaucoma (OR = 2.09), and use of glaucoma eye drops (OR = 3.33). Survival analysis showed that the treated glaucoma group reached the near add power endpoint of ≥1.50 D (symptomatic presbyopia) significantly earlier than the other two groups, and there was no difference between the control and untreated glaucoma groups., Conclusions: Glaucoma patients treated with eye drops may start near correction earlier., Translational Relevance: Symptomatic presbyopia may develop earlier in patients with glaucoma, and our findings could further contribute to better management and understanding of presbyopia with glaucoma.

Introduction: The role of ophthalmologists is defined by tasks requiring visual effort, emphasizing the importance of examining their condition within the realm of occupational visual health. Our goal was to explore the occurrence of asthenopia among Chinese ophthalmologists and identify contributing factors through the use of a reliable and validated survey instrument., Methods: A national cross-sectional online survey was carried out in June 2017, involving 6,220 practicing ophthalmologists in China. Utilizing an 11-item Asthenopia Survey Questionnaire with established reliability and validity. Prevalence rates of asthenopia among subgroups categorized by age, gender, hospital classification, physician level, daily near vision activity duration, sleep duration, sleep quality, presbyopia status, and history of eye surgery were determined using the independent t -test, chi-square test and bonferroni test. Multiple logistic regression analysis was employed to pinpoint independent factors linked to asthenopia., Results: Out of the 5,009 ophthalmologists who completed the survey, a 40.7% prevalence of asthenopia was identified. Multivariate analysis revealed that good sleep quality (OR: 0.24, 95%CI: 0.20-0.30), moderate sleep quality (OR: 0.47, 95%CI: 0.38-0.59), engaging in daily near vision activities for less than 7 h (OR: 0.76, 95%CI: 0.68-0.86), having daily sleep duration exceeding 7 h (OR: 0.87, 95%CI: 0.77-0.98), and working in tertiary hospitals (OR: 0.88, 95%CI: 0.78-0.99) were protective factors against asthenopia. Conversely, presbyopia was identified as a risk factor (OR: 1.33, 95%CI: 1.04-1.70). All calculated p values were below 0.05. Age, gender, physician level, and eye surgery history were not related factors., Conclusion: Asthenopia is prevalent among Chinese ophthalmologists, with employment in tertiary hospitals providing a protective effect and presbyopia is a risk factor. Preventive strategies include improving sleep quality, restricting daily near vision activity to under 7 h, and extending daily sleep duration to over 7 h. Further investigation is needed to explore the protective implications of working in tertiary hospitals., Competing Interests: The authors declare 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 © 2023 Lin, Zhu, Wu, Yang, Lu and Deng.)

Background: Aged Zanzibari women are in a disadvantaged position, having high demand for near-vision spectacles. Currently, there is no information on the eye health status of craftswomen, which makes planning a women-targeted project to deliver eye health services to older craftswomen in Zanzibar difficult. We assessed the prevalence of vision impairment, refractive error, presbyopia, effective spectacle coverage (distance and near) and attitude towards spectacle wearing among older Zanzibari craftswomen., Methods and Analysis: This was a cross-sectional study. Unaided and presenting distance and near vision of craftswomen 35 years and older were assessed at the women's co-operatives. We determined the number of those with distance vision poorer than 6/12 and their causes (distance-vision impairment), the number of those with near vision poorer than N8 at 40 cm (presbyopia) and the number of those whose distance and/or near-vision needs were met adequately with their habitual spectacles (effective distance and near spectacle coverages). A piloted and validated questionnaire (15 statements) was used to determine their attitude towards spectacle wearing., Results: In all, 263 craftswomen participated in the survey (mean age 52.1 years±9.4 years). The prevalence of distance vision impairment among the craftswomen was 29.7% (95% CI 24.2% to 35.6%), the primary cause being uncorrected refractive error (n=51, 65.4%), and none were corrected. The prevalence of presbyopia was 86.6% (95% CI 81.5% to 90.7%, n=231) and the effective near spectacle coverage was 0.99%. The craftswomen showed a positive attitude towards spectacle wearing (strongly agree or agree) based on 12 out of 15 statements., Conclusion: The high burden of vision impairment, uncorrected distance refractive error and presbyopia, and a positive attitude towards spectacle wearing among older craftswomen in Zanzibar indicated the need for women-targeted eye health programmes in low-resource settings., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Clinical Relevance: Country-specific estimates of the prevalence of refractive errors are important to formulate national eye health policies for refractive care services., Background: The purpose of this study was to systematically synthesise available literature and estimate the prevalence of refractive errors in the Nepalese population., Methods: PubMed, Scopus, and Web of Science databases were systematically searched for articles on refractive errors and presbyopia published in English language until 27 September 2022. Population and school-based quantitative, cross-sectional prevalence studies and Rapid Assessment of Avoidable Blindness survey repository data were included. The quality of the included studies was assessed using the Newcastle Ottawa scale adapted for cross-sectional studies. Data extraction was performed with consensus among the reviewers. Meta-analysis of the prevalence was performed using the Random effects model to estimate the pooled proportions., Results: A total of 38 studies with 101 701 participants were included: 18 studies in children (n = 31 596) and 20 in adults (n = 70 105). In children, the estimated pooled prevalence of overall refractive errors was 8.4% (95% CI: 4.8 to 12.9) with myopia, hypermetropia and astigmatism prevalent in 7.1% (95% CI: 3.7 to 11.4), 1.0% (95% CI: 0.7 to 1.3) and 2.2% (95% CI: 0.9 to 3.9), respectively. In adults, the prevalence of refractive errors, uncorrected refractive errors, and uncorrected presbyopia were 11.2% (95% CI: 8.0 to 14.9), 7.3% (95% CI: 5.4 to 9.5) and 78.9% (95% CI: 69.1 to 87.3), respectively., Conclusions: The pooled prevalence of refractive errors is relatively low while uncorrected refractive errors and presbyopia are high in Nepalese population suggesting a need for better access to refractive care services in the country. The paucity of quality evidence on prevalence of refractive errors, particularly in children, indicates a need for a well-designed population-based study to accurately estimate the current prevalence of refractive errors.

Objective: To estimate the burden of potential productivity losses due to uncorrected and under-corrected presbyopia in LMICs among the working-age population in both the cross-sectional and longitudinal manner., Methods: We extracted data for the prevalence of presbyopia from the Global Burden of Diseases (GBD), Injuries, and Risk Factors Study 2019. Data for the gross domestic product (GDP) per capita were extracted from the World Bank database and Central Intelligence Agency's World Factbook. We introduced life table models to construct age cohorts (in 5-year age groups) of the working-age population (aged from 40 to 64 years old) in LMICs, with simulated follow-up until 65 years old in people with and without uncorrected presbyopia. The differences in productivity-adjusted life years (PALYs) lived and productivity between these two cohorts were calculated. The potential productivity loss was estimated based on GDP per capita. The WHO standard 3% annual discount rate was applied to all years of life and PALYs lived., Results: In 2019, there were 238.40 million (95% confidence interval [CI]: 150.92-346.78 million) uncorrected and under-corrected presbyopia cases in LMICs, resulting in 54.13 billion (current US dollars) (95% confidence interval [CI]: 34.34-79.02 billion) potential productivity losses. With simulated follow-up until retirement, those with uncorrected and under-corrected presbyopia were predicted to experience an additional loss of 155 million PALYs (an average loss of 0.7 PALYs per case), which was equivalent to a total loss of US$ 315 billion (an average loss of US$ 1453.72 per person)., Conclusions: Our findings highlight the considerable productivity losses due to uncorrected and under-corrected presbyopia in LMICs, especially in a longitudinal manner. There is a great need for the development of enabling eye care policies and programs to create access to eye care services, and more healthcare investment in the correction of presbyopia in the working-age population in LMICs. This study could provide evidences for some potential health-related strategies for socio-economic development., Competing Interests: The authors declare 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 © 2022 Ma, Chen, Li, Zhou, Du, Yin, Chen, Wang, Jiang, Guan and Qiu.)

Significance: Presbyopia typically occurs around 40 years of age and affects approximately one-quarter of the global population. Up to October 2021, there were no approved pharmacotherapies for presbyopia, and common treatments, such as glasses, can have disadvantages for individuals' health-related quality of life., Purpose: This study aimed to document the experience of living with and managing presbyopia, identify perspectives on treatment options, and determine whether there is an unmet need in the treatment landscape., Methods: Coded transcripts of concept elicitation (CE; n = 20) and cognitive debriefing (n = 20) interviews with presbyopic individuals, originally conducted for development of patient-reported outcome instruments, were reanalyzed to identify salient concepts describing participants' experiences with presbyopia treatments. Qualitative ranking exercises assessed participants' preferences for a potential pharmacotherapy vs. existing treatments., Results: Because most concepts were identified with the CE interviews, data reflect CE findings unless otherwise noted. Average age across CE/cognitive debriefing interviews was 49.4 years; a vast majority of participants used glasses for presbyopia treatment. Four themes related to treatment with glasses were identified with the interviews: inconvenience during daily activities, negative physical sensations around the eyes/head, limitations, and undesirable impacts on daily life (e.g., psychosocial). Most commonly, participants reported inconveniences related to forgetting glasses and psychosocial impacts (e.g., feeling/looking older). Strained/tired eyes and limited ability to see at varying distances were also reported. Among participants with near-vision glasses who provided data, two-thirds expressed interest in alternative treatments. In addition, almost three-quarters of the participants ranked hypothetical eye drops as their first or second preferred option, vs. reading glasses, contact lenses, magnifying glasses, and surgery., Conclusions: This study explored the experience of living with and managing presbyopia and identified limitations and negative impacts of current treatments. Pharmacological development (e.g., eye drops) may fulfill an unmet need in the presbyopia treatment landscape., Competing Interests: Conflict of Interest Disclosure: This study was sponsored by Allergan (prior to its acquisition by AbbVie Inc., North Chicago, IL). The sponsor participated in the study design, data collection, analysis and interpretation, project administration, and preparation, review, and approval of the manuscript., (Copyright © 2022 American Academy of Optometry.)

Purpose: Presbyopia is a serious burden in the aged population, however, the factors affecting its progression have not been fully determined. The aim of this study was to explore the association between the time of starting to wear presbyopic eyeglasses and lifestyle, in participants aged from 40 to 59 years., Methods: We selected the sample to be representative of sex and age for the age group 40 to 59 years . Participants completed a web-based survey on presbyopia-related questions, symptomatic dry eye, sleep habits, Pittsburgh Sleep Quality Index, subjective happiness scale (SHS), and other lifestyle-related questions including marital status, income, screen time, sun exposure, family history of myopia, and the frequency of regular visits to medical services., Results: We found 529 participants (26.5%) used near correction, with a mean age for first near correction of 47.8±4.8 years. An earlier commencement of near correction correlated with hyperopia ( P = 0.013), late wake-up time ( P = 0.010), a poor subjective sleep quality score ( P = 0.019), and a low annual income score ( P = 0.025), after adjusting for age and sex. Stratification by income demonstrated the low-income group exhibited more dry eye, later wake-up time, longer sleep latency, longer sleep duration, worse sleep efficacy, lower SHS score, and a higher prevalence of living alone compared with the high-income group. The usage of corrective devices did not differ between the two groups., Conclusions: The current study suggests a healthy sleep habit may delay the need for near correction, in addition to myopia. Shift work and circadian rhythm disruption might exacerbate presbyopia progression., Competing Interests: KT is employed by Tsubota Laboratory, Inc. The remaining authors declare 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 © 2022 Ayaki, Negishi, Kawashima and Tsubota.)

Clinical Relevance: Effective spectacle coverage is a useful indicator to assess the coverage of refraction services in a given region. We found a low coverage in the Akividu region suggesting a need to develop effective refraction services., Background: To assess the prevalence of spectacle use and effective spectacle coverage for distance vision among people aged 40 years and older in the Indian state of Andhra Pradesh., Methods: A population-based cross-sectional survey was carried out in the Akividu region in West Godavari and Krishna districts. The study teams visited selected households and conducted eye examinations in the selected clusters. A structured questionnaire was used to collect information on spectacle use. 'Met Need' was defined as unaided VA worse than 6/12 but improved to 6/12 or better with their current spectacles. 'Unmet Need' was defined as unaided VA worse than 6/12 but improved to 6/12 with pinhole, among those not using spectacles. The 'Under-met Need' was defined as aided VA worse than 6/12 but improving with pinhole to 6/12 or better. Based on these definitions, Effective Refractive Error Coverage (e-REC) is calculated as: e-REC (%) s = ((met need)/(met need + under-met need + unmet need)) X100., Results: Of 3,000 enumerated from 60 clusters, 2,587 (86.2%) participants were examined. The prevalence of current spectacle use was 43.1% (95% CI:41.2-45.0). The e-REC was 37.4%. It was also lower in men compared to women and among those without any education. Participants who had cataract surgery in either eye had similar e-REC compared to those who were not operated., Conclusion: Though spectacle use was found to be high, there is a still large unmet need for refractive correction for distance. Effective service delivery models to provide refraction and spectacle dispensing services are needed to achieve universal eye health coverage in the region.

Purpose: The aim of this cohort study was to evaluate the development and progression of presbyopia and the status of dry eye-related symptoms from 2017 to 2020, to assess the impact of the COVID-19 pandemic., Methods: Near add power at 30 cm was measured in 339 participants aged between 40 and 55 from 2017 to 2021 at Japanese eye clinics. Regression analysis of near add power and age was analyzed to compare 2017 with later years up to the pandemic. The prevalence of dry eye-related signs and six common symptoms were compared., Results: The number and mean age (y) of participants were 183 (48.6±4.1) in 2017, 46 (51.3±7.5) in 2019, and 110 (49.2±3.7) in 2020-21, respectively. The mean progression rate of near add power (D/y) was 0.13 for 2017, 0.09 for 2019 (P = 0.028, vs 2017), and 0.08 for 2020-21 (P<0.001, vs 2017). The slope (rate of presbyopia progression) became flatter from 2017 to 2021 and the estimated near add power at the age of 40 increased from 2017 to 2020-2021, implicating presbyopia developed earlier and worsened during the study period. The 2017 values were comparable with previous studies described in 1922 and 2019. The standardized correlation coefficient between age and near add power was 0.816 for 2017, 0.671 for 2019 (P = 0.084, vs 2017), and 0.572 for 2020-21 (P<0.001, vs 2017). Multiple regression analysis revealed age and COVID-19 pandemic were significantly correlated with near add power. The prevalence of dryness irritation, and pain was greater in 2020-21 than in 2017 with no difference in the prevalence of eye fatigue, blurring, and photophobia. There was no difference in the prevalence of short tear break-up time and positive corneal staining among 2017, 2019 and 2020-21., Conclusion: Estimated presbyopia developed earlier and progressed slower from 2017 to 2021, the COVID-19 pandemic. Stress and rapid digitalization related to strict infection control and quarantine might be contributing factors., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To determine the prevalence of presbyopia and its association with elevated glycemic levels in subjects ≥40 years of age in the South Indian population of Chennai., Methods: This was a retrospective study. Subjects were included from the Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular genetics Study (SN-DREAMS 1). Demographic data, detailed medical and ocular history, comprehensive eye examination, and biochemical investigations were performed. Glycosylated hemoglobin results were categorized as controls (4%-5.6%), prediabetic (5.7%-6.4%), and diabetic (≥6.5%) groups. The given presbyopic correction was divided into two groups as within and outside donders limit. Prevalence rates and mean values were determined and compared among the three glycemic groups. The Student t test, the Chi-square test, and multivariate logistic regression analyses were performed., Results: The overall prevalence of presbyopia from our previously conducted SN-DREAMS 1 population of 1414 patients was 79.77% (95% CI: 0.775-0.818). In total, 1128 participants were included for our current secondary analysis with a mean age of 54.40 years (range: 40-83). The number of subjects within and outside donders limit was 1044 (92.55%) and 84 (7.44%), respectively. In each age group (40-49, 50-59, ≥60) regardless of being within or outside donders limits, an increasing trend in the prevalence of presbyopia was noted based on increasing glycemic levels., Conclusion: Our study demonstrated a high prevalence of presbyopia in the South Indian population of Chennai. Findings show that the prevalence of presbyopia in different age groups increases with worsening diabetes status., Competing Interests: None

Purpose: To investigate the prevalence and factors associated with uncorrected presbyopia among rural community dwellers in Japan., Study Design: A population-based cross-sectional study was conducted in 2011 among community dwellers aged 40-74 years who received specific health checkups in Minamiaizu and Tadami, Fukushima Prefecture, Japan., Methods: Uncorrected presbyopia was considered as when the distance-corrected visual acuity in the better eye was ≥0.5 and the near-presenting visual acuity in the better eye was <0.4, regardless of distance refractive status. Multiple logistic regression analysis was employed to calculate the odds ratios (ORs) for uncorrected presbyopia and to adjust for possible confounders., Results: A total of 2054 individuals participated in the specific health checkups. In the 1156 individuals (response rate: 56.28%) analyzed in the study, the mean (SD) age was 63.0 (8.7) years, the percentage of women was higher (57.87%), and the prevalence of uncorrected presbyopia was 26.38% (95% CI 23.86%-29.03%). Multivariate analysis revealed that the factors associated with uncorrected presbyopia were older age (adjusted OR: 1.054 [95% CI: 1.034-1.075]), female sex (adjusted OR: 1.388 [95% CI: 1.006-1.915]), and distance-presenting vision impairment (adjusted OR: 2.651 [95% CI: 1.697-4.143])., Conclusion: Approximately one-quarter of the participants in this study from a rural population of Japan did not have adequate near vision. It is recommended that a public health intervention should be enacted to correct presbyopia, especially in the older age group, women, and those with uncorrected refractive errors., (© 2021. Japanese Ophthalmological Society.)

Purpose: To estimate the prevalence of computer vision syndrome (CVS) in presbyopic digital device workers using two ophthalmic progressive lens designs during the working day, and to analyse the association of CVS with sociodemographic, occupational, digital device exposure and refractive factors., Methods: This time series, quasi-experimental design study included 69 presbyopic digital device workers (age range: 46-69 years; mean ± SD = 54.7 ± 5.0). All used desktop computers at their workplace. Progressive addition lenses (PALs) and occupational lenses were used for three months each. CVS was measured with the CVS-Q © questionnaire before intervention (baseline) and at 1 week, 1 month and 3 months after wearing the lenses. A multivariate logistic regression model was used to identify the factors that were associated with an improved CVS-Q © score., Results: 37.7% of the subjects were female and 78.3% were ametropes; 65.2% had advanced presbyopia. 56.2% used digital devices at work >6 h day -1 . The prevalence of CVS at baseline, after wearing PALs for three months and after three months of occupational lens wear was 68.1%, 33.3% and 18.8%, respectively. The mean CVS-Q © score was lower with occupational lenses than with PALs (p = 0.001). 40.6% of the digital device workers improved their CVS-Q © score ≥2 points with the occupational lenses. Ametropes were less likely than emmetropes to improve with occupational lenses (OR = 0.27, p = 0.05). 89.8% of the sample workers were satisfied or very satisfied with the occupational lenses and 71% were similarly satisfied with the PALs. 73.9% chose the occupational lenses as their first choice of lens for digital device use, compared with 17.4% for PALs., Conclusions: Computer vision syndrome is reduced in presbyopic desktop computer workers wearing occupational lenses compared with PALs, especially in emmetropes., (© 2021 The Authors Ophthalmic and Physiological Optics © 2021 The College of Optometrists.)

Aim: To determine the prevalence and causes of blindness, vision impairment and cataract surgery coverage among Rohingya refugees aged ≥ 50 years residing in camps in Cox's Bazar, Bangladesh., Methods: We used the Rapid Assessment of Avoidable Blindness (RAAB) methodology to select 76 clusters of 50 participants aged ≥ 50 years with probability proportionate to size. Demographic and cataract surgery data were collected using questionnaires, visual acuity was assessed per World Health Organization criteria and examinations were conducted by torch, and with direct ophthalmoscopy in eyes with pinhole-corrected vision <6/12. RAAB software was used for data entry and analysis., Results: We examined 3,629 of 3800 selected persons (95.5%). Age and sex adjusted prevalence of blindness (<3/60), severe visual impairment (SVI; >3/60 to ≤6/60), moderate visual impairment (MVI; >6/60 to ≤6/18), and early visual impairment (EVI; >6/18 to ≤6/12) were 2.14%, 2.35%, 9.68% and 14.7% respectively. Cataract was responsible for 75.0% of blindness and 75.8% of SVI, while refractive error caused 47.9% and 90.9% of MVI and EVI respectively. Most vision loss (95.9%) was avoidable. Cataract surgical coverage among the blind was 81.2%. Refractive error was detected in 17.1% (n = 622) of participants and 95.2% (n = 592) of these did not have spectacles. In the full Rohingya cohort of 76,692, approximately 10,000 surgeries are needed to correct all eyes impaired (<6/18) by cataract, 12,000 need distance glasses and 73,000 require presbyopic correction., Conclusion: The prevalence of blindness was lower than expected for a displaced population, in part due to few Rohingya being ≥60 years and the camp's good access to cataract surgery. We suggest the United Nations High Commissioner for Refugees include eye care among recommended health services for all refugees with long-term displacement., Competing Interests: The authors have declared that no competing interest exist.

Background/aim: To investigate normative patterns and factors associated with presbyopia progression in a multiethnic Asian population., Methods: Malay, Indian and Chinese participants aged 40-80 years who had baseline and 6-year follow-up examinations with subjective refraction data were recruited from the Singapore Epidemiology of Eye Diseases Study. Presbyopia progression was defined as an increase in near addition power of ≥+0.50 dioptre (D) from baseline to follow-up visit. Modified Poisson regression analyses were used to determine baseline factors associated with presbyopia progression., Results: From the eligible 3974 eyes, 2608 eyes were included for final analysis after excluding eyes with a history of cataract surgery (929 eyes) and best-corrected distance visual acuity worse than 20/40 (342 eyes). Overall the mean near addition power change over 6 years was +0.25 D; Malays showed greater change (+0.37 D) compared with Indians (+0.23 D) and Chinese (+0.16 D). After adjusting for baseline age, gender, body mass index, hypertension, cataract, refractive error and daily hours of reading and writing, Malays were more likely to have presbyopia progression compared with Chinese (RR (relative risk)=1.67; 95% CI 1.43 to 1.95; p<0.001) and Indians (RR=1.45; 95% CI 1.25 to 1.68; p<0.001). Individuals aged 60-69 years (RR=0.77; p=0.006) and ≥70 years (RR=0.51; p<0.001) were less likely to progress in presbyopia compared with those aged 40-49., Conclusion: In this Asian population, the near addition power change over 6 years was lower than the current near addition prescription guidelines (+0.25 D vs +0.60 D). Our findings may help update near addition prescription guidelines that can be more tailored to Asians., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Presbyopia is a decline in the amplitude of accommodation with the onset in the age range 40-45 years affecting near visual task performance. As the age of presbyopia onset coincides with productive age, it results in great productivity loss especially in those with high near visual demand like teachers. A maximum near vision potential is essential for teachers in ensuring the quality of education, as most of the students' evaluations and scripts are assessed manually in Ethiopia. The prevalence of unmet need for presbyopia correction among school teachers ranges from 38.5-70.4% worldwide. Though presbyopia is a common ocular condition, there is limited evidence regarding the unmet need for presbyopia correction in Ethiopia as well as in Hawassa city. Therefore, this study aimed to determine the magnitude of unmet need for presbyopia correction and its associated factors among school teachers in Hawassa city, South Ethiopia., Methods: A school-based cross-sectional study was conducted among teachers older than 35 years. A simple random sampling technique was used to select participants using name lists as a sampling frame from 69 schools. The participants selected underwent for distance and near visual acuity test. Those with distance visual acuity of 6/12 or worse were refracted before near visual acuity test. Information on the spectacle use and associated factors was obtained using the interviewer-administered questionnaire. Data analysis was done using Statistical Package for Social Sciences software version 20. Binary logistic regression analysis was performed to assess association between independent variables and the unmet need for presbyopia correction., Results: A total of 459 study participants were included in the study with a response rate of 95.21%.The unmet need for presbyopia correction was 51.26% (95%CI: 46.7-55.6%). Female gender (AOR = 2.50; 95%CI: 1.51-4.15), age 36-45 (AOR = 4.12; 95%CI: 1.46-11.76), unaware of presbyopia (AOR = 2.36; 95%CI: 1.2-4.66) and self-rating of current vision as good (AOR = 3.5; 95%CI: 1.61-7.6) were factors significantly associated with the unmet need for presbyopia., Conclusions: The burden of unmet need for presbyopia correction is a moderate priority according to the World Health Organization for presbyopia correction services criteria. A school-based presbyopia awareness creation program is important to reduce this huge burden.

Purpose : Recent global, regional and country-level prevalence estimates for blindness and vision impairment will be important when designing future public health policies. The aim of this paper is to contribute to this discussion by estimating the productivity impact of known effective interventions to treat all preventable cases of vision impairment at the global, regional and country-level up to 2050. We also provide estimates of potential reduction in the number of people with vision impairment, as well as averted vision-impaired years up to 2050. Methods : We combined recent estimates of the prevalence of blindness, distance and near vision impairment with the World Bank's World Development Indicators (WDI) and estimated the global, regional and country-level productivity gains up to 2030, 2040 and 2050 from known effective interventions, primarily cataract surgery and treated uncorrected refractive errors. The magnitude of productivity gains relative to baseline depended on population size, estimated current and future prevalence of vision impairment, level of economic development, long-term wage growth, and long-term real interest rates. Results : Globally, we estimate that the number of people affected by blindness could be reduced from the estimated 114.6 million by 2050 to 58.3 million. This would be associated with over one billion blind life-years averted and US$ 984 billion in global productivity gains. These numbers are dwarfed by the impact of interventions to reduce the prevalence of Moderate and Severe Vision Impairment (MSVI) [Presenting Acuity <20/60 to 20/400 in the better-seeing eye]. We estimate that the number of people affected by MSVI could be reduced by 435.8 million people to 147.9 million by 2050. This reduction would translate to over 9 billion MSVI -life-years avoided and US$ 17 trillion in productivity gains by 2050. While other causes of VI would not be possible to eliminate completely based on current known effective treatments, low-cost interventions to eliminate VI from uncorrected presbyopia would avert 1.2 billion presbyopia life-years and achieve US$ 1.05 trillion in productivity gains by 2050. In total, the global productivity gains for all three categories are estimated to be US$ 19 trillion by 2050. East Asia makes up the greatest share of productivity gains due to the high number of people affected by VI and the region's continuing economic growth. Conclusion : Implementation of currently known and effective treatments of avoidable blindness, MSVI and presbyopia would be expected to contribute significant productivity gains to the global economy at a fraction of the estimated costs to deliver them.

This cross-sectional study estimated computer vision syndrome (CVS) prevalence and analysed its relationship with video display terminal (VDT) exposure, as well as sociodemographic, refractive, environmental, and ergonomic characteristics in 109 presbyopic VDT workers wearing progressive addition lenses (PALs). Usual spectacles were measured with a lens analyser, and subjective refraction was performed by an optometrist. CVS was measured with the CVS-Q©. VDT exposure was collected. Ergonomic evaluations were conducted in a normal working posture looking at the screen. Air temperature and relative humidity were measured (thermohygrometer), and illumination was measured (luxmeter). Descriptive analysis and differences in CVS prevalence, as a function of the explanatory variables, were performed (chi-square test). Multivariate logistic regression was used to identify factors associated with CVS (OR and 95% CI). The mean age was 54.0 ± 4.8 years, and 43.1% were women. The mean hours of VDT use at work was 6.5 ± 1.3 hours/day. The prevalence of CVS was 74.3%. CVS was significantly associated with women (OR 3.40; 95% CI, 1.12-10.33), non-neutral neck posture (OR 3.27; 95% CI, 1.03-10.41) and altered workplace lighting (OR 3.64; 95% CI, 1.22-10.81). Providing training and information to workers regarding the importance of adequate lighting and ergonomic postures during VDT use is advised to decrease CVS and increase workplace quality of life.

The aim of this paper is to assess the eye health needs of school teachers in the Asutifi districts of Ghana. Presenting distance visual acuity was measured in each eye. Those with visual acuity of <6/12 in one or both eyes had subjective refraction. All underwent basic eye examination and near functional vision was assessed for teachers aged ≥35 years using the Near Activity Visual Questionnaire (NVAQ). Teachers with uncorrected presbyopia were given a near correction and NVAQ was assessed again at two weeks. Three hundred teachers were examined with mean (SD) age of 36.5 (9.7) years, 54.3% were male and 6.3% (95% CI: 3.8 to 9.8%) had a presenting acuity of <6/12 in one or both eyes. The estimated prevalence of moderate visual impairment was 0.7% (95% CI: 0.08 to 2.4%). Lens opacities (50%) and refractive error (18%) were the main causes of visual loss. Seventy-five out of 136 (55.1%, 95% CI: 46.6 to 63.4%) of teachers aged ≥35 years were presbyopic, 45.3% (95% CI: 36.9 to 53.7%) of whom had presbyopic correction. Lack of awareness was the major barrier to presbyopic correction. Median Rasch score for teachers given presbyopic correction ( n = 39) decreased by 60.6% from 46.0 (IQR: 10.7 to 72.8) to 18.1 (IQR: 0 to 58.9) and overall satisfaction with near vision improved at follow up. Prevalence of presbyopia was high, and spectacles improved satisfaction with near vision.

Presbyopia is the progressive loss of accommodation. Accommodation is a quick, precise and involuntary action which enables the eye to change the power of the young crystalline lens to see clearly at all distances. Presbyopia is and age-linked physiologic phenomenon: it results from aging of the lens, which loses its elasticity, gradually becomes rigid and loses the ability to accommodate. Presbyopia has attained a prevalence of 80% in Europe and is increasing regularly due to the aging of the population. Various surgical techniques can be proposed. Indications depend on age, ophthalmological exam, and any associated ametropia. The main techniques act by either changing the curvature of the cornea with laser or with an intrastromal inlay to create pseudoaccomodation, or by intraocular lens surgery with a multifocal or accommodating IOL. Once the surgical choice has been made, the information must be clearly conveyed and consent obtained., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Importance: Presbyopia, an essentially universal, age-related loss of the ability to focus un-aided on near objects, is the world's leading cause of visual impairment., Background: Smartphone use is widespread in China, but little is known about the prevalence, determinants and correction of difficulties with smartphone use in the setting of presbyopia., Design: Cross-sectional data from a population-based longitudinal cohort study., Participants: A total of 1817 persons aged ≥35 years in Guangzhou, Southern China., Methods: Participants underwent near visual acuity (NVA) testing and completed questionnaires on smartphone usage detailing knowledge of their own presbyopia status, frequency (hours/day) and subjective difficulties with use of mobile and smartphones. Presbyopia was defined as uncorrected bilateral NVA ≤6/12 with best-corrected bilateral NVA >6/12., Main Outcome Measures: Difficulty in smartphone use associated with uncorrected presbyopia., Results: Among 1427 respondents (78.5%) undergoing examination, 1191 (83.5%) completed questionnaires (mean age 52.3 ± 11.6 years; 54.9% women). Among 451 persons (37.8%) with presbyopia owning smartphones, 290 (64.3%) reported difficulty using them. Multiple ordinal logistic regression modelling showed difficulty in smartphone use due to presbyopia was associated with higher educational level (P = .013), worse NVA (P < .001) and more time spent using smartphones (P = .002 for 1-3 hours/day). Among persons with presbyopia owning smartphones, 353 (78.0%) said they would pay >US$15 (median US$45) for innovations making smartphone use easier., Conclusions and Relevance: Difficulty in using smartphones in the presence of presbyopia is common and affected persons are willing to pay for useful solutions to the problem., (© 2019 Royal Australian and New Zealand College of Ophthalmologists.)

Significance: Uncorrected refractive error is the leading cause of visual impairment; therefore, reducing its prevalence is important worldwide. For two decades, there has not been a comprehensive assessment of refractive error in Latin America., Purpose: The purpose of this study was to determine the current prevalence of refractive error, presbyopia, spectacle coverage, barriers to uptake refractive services, and spectacle correction in people 15 years and older in Bogotá, Colombia., Methods: A cross-sectional community-based survey was conducted using 50 randomly selected clusters from 10 districts of Bogotá reflecting the socioeconomic status of the city. Respondents 15 years and older were interviewed and underwent standardized clinical eye examinations. Prevalence of uncorrected refractive error, spectacle coverage, and visual impairment were standardized to 2015 age-sex population distribution of Bogotá and further analyzed., Results: A total of 2886 subjects (90% of 3206 eligible subjects) participated in the study; 39.1% were male and 60.9% were female in the age range of 15 to 96 years, with a median age of 46 years (interquartile range, 45 to 54 years). Age- and sex-standardized prevalence of visual impairment was 19.3% (95% confidence interval [CI], 17.8 to 20.8%). Prevalence of uncorrected refractive error was 12.5% (95% CI, 11.3 to 13.7%). Prevalence of presbyopia among participants 35 years and older was 55.2% (95% CI, 52.9 to 57.4%). Spectacle coverage was 50.9% for distance vision, and it was 33.9% for presbyopia. Main barrier to spectacle uptake was a limitation in affording spectacles because of economic factors (29.5%)., Conclusions: This study provides a current estimate of refractive error using the Rapid Assessment of Refractive Error for Colombia and the Latin American region. The prevalence of uncorrected refractive error and presbyopia was high, and the barriers to spectacle uptake were higher in the lowest socioeconomic strata. The results obtained in the present study will help in making evidence-based decisions related to eye care service delivery in Colombia.

Purpose: The objective of this review is to estimate the prevalence of refractive errors, uncorrected refractive error (URE), and uncorrected presbyopia in adults aged ≥30 years in India., Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. A detailed literature search was performed to include all studies published from India from the year 1990 using the Cochrane Library, Medline, and Embase. Refractive error was defined by >0.50 D ametropia. URE was defined by presenting visual acuity (PVA) worse than 6/18 improving with pinhole or spectacle correction, and uncorrected presbyopia by near vision

Introduction: Addition in patients of less than 40 years is not uncommon in our practice. We investigated the need for addition after objective refraction and thus determine the average age of onset of the presbyopia., Methods: We conducted a cross-sectional descriptive study of patients aged 35-45 years at the Central Hospital of Yaoundé over a period of three months. All patients underwent cycloplegic refraction. Distance visual acuity was corrected after instillation of cycloplegic eye drops while near addition was assessed two days later when the cycloplegia was no longer effective. Possible additional distance correction was done 2 days after cycloplegia. Statistical analysis was done using IBM SPSS 20.0 software., Results: We examined 55 patients, 110 eyes. The average age of patients was 41.87±2.5 years, the sex-ratio was 0.28. There was a female predominance. Hypermetropic astigmatism was the most common ametropia (58.2% of cases) followed by hyperopia (24.6%).No patient was myopic. the average age of presbyopia onset in this age group was 43.2±1.7 years. After objective correction of distance visual acuity, no patient needed for addition before the age of 40. Moreover, 4 out of 10 patients with hypermetropic ametropia did not need addition before the age of 40. Addition was significantly associated with age., Conclusion: The average age of presbyopia onset is 43.2±1.7 years. Before the age of 45, addition must be preceded by objective refraction., Competing Interests: Les auteurs ne déclarent aucun conflit d'intérêts.

Background: Ambient air pollutant directly contacts with the eyes, however, the effect of ambient fine particulate matter (PM 2.5 ) and ozone (O 3 ) on vision impairment, such as presbyopia, has been kept largely unknown., Methods: We surveyed a total of 36,620 participants aged 50 years and above in six low- and middle-income countries. Ambient annual concentrations of PM 2.5 and O 3 for the residential community were estimated using satellite data and chemical transport model. A mixed effects model was utilized to assess the effects of ambient PM 2.5 and O 3 on presbyopia, as well as their combined effects., Results: A total of 13,841 presbyopia cases were identified among the participants with a prevalence rate of 41.17%. For both PM 2.5 and O 3 , we found a J-shaped exposure-response relationship with the threshold being identified at 15 μg/m 3 for PM 2.5 and 55 μg/m 3 for O 3 . The odds ratio (OR) of presbyopia was 1.15 (95% CI: 1.09, 1.21) for each 10 μg/m 3 increase in PM 2.5 above 15 μg/m 3 and 1.37 (95% CI: 1.23, 1.54) for O 3 above 55 μg/m 3 after adjusting for various potential confounding factors. There appeared to be a synergistic interaction between ambient PM 2.5 and O 3 on presbyopia in the additive model, the combined effect was significantly larger than the sum of their individual effects, with a synergistic index of 2.39., Conclusion: This study supports that exposures to ambient PM 2.5 and O 3 might be important risk factors of presbyopia among old adults, and simultaneously exposure to high level of the two pollutants could intensify their individual effects., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Importance: This study helps to better understand the need and trend in presbyopic add power in the aging society., Background: Distribution and progression of presbyopic add power in East Asian population is largely unknown., Design: Prospective cohort study., Participants: About 303 participants from a population-based study of residents aged 35 years and older in Guangzhou, China., Methods: Visual acuity (VA) test and non-cycloplegic automated refraction were performed at baseline in 2008 and the 6-year follow-up per standardized protocol. Participants with presenting near VA ≤ 20/40 underwent distance subjective refraction and add power measurement by increasing plus lens at a standard distance of 40 cm at each visit., Main Outcome Measures: Add power at baseline and follow-ups., Results: Mean (standard deviation) age of the study participants was 57.6 (11.1) years and 50.2% were female. The mean add power at baseline was 1.43, 1.73, 2.03 and 2.20 diopters (D) for individuals in the age groups of 35-44, 45-54, 55-64 and 65+ years, respectively. Participants with older age and lower educational level had significantly higher add power requirements (P < 0.001). The overall 6-year increase in add power was 0.15D (95% CI: 0.06 to 0.25), and was smaller in myopic subjects (P = 0.03). Baseline age and add power, but not changes in biometric factors, were associated with longitudinal change in add power (P < 0.001)., Conclusions and Relevance: Distribution and progression of add power in Chinese was different from that previously suggested by Caucasian studies. More studies are needed to establish up-to-date age-related add power prescription norms for population of different ethnicities., (© 2018 Royal Australian and New Zealand College of Ophthalmologists.)

Aims: To investigate the prevalence and incidence of presbyopia in an urban Chinese population., Methods: 1817 subjects aged ≥35 years were identified by random cluster sampling in Yuexiu District, Guangzhou, China, at baseline in 2008, and all were invited for the follow-up examination in 2014. Distance and near visual acuity (VA) tests, as well as non-cycloplegic automated refraction were performed at each examination as per standardised protocol. Participants with presenting near VA ≤20/40 were further tested with add power at a standard distance of 40 cm to obtain their best-corrected near VA. Functional presbyopia was defined as near VA under presenting distance refraction correction of <20/50 and could be improved by at least one line with add power., Results: A total of 1191 (83.5% of the 2014 follow-up) participants were included in the current analysis with a mean (SD) age of 50.4 (9.7) years, and 52.9% were female. Prevalence of functional presbyopia at baseline was 25.2% (95% CI 21.5 to 28.9) and the 6-year incidence was 42.8% (95% CI 39.4 to 50.1). Older and more hyperopic subjects had both higher prevalence and incidence of presbyopia (P<0.001). Average presbyopic correction coverage (PCC) was 87.7% at baseline and was significantly lower in myopic participants (P=0.006)., Conclusions: Prevalence of functional presbyopia in urban China is relatively lower along with a higher PCC compared with previous population-based rural cohorts. We identified a high presbyopia incidence, and further studies are needed to understand longitudinal presbyopia progression as well as the urban-rural gap in presbyopia to throw light on future strategic planning., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Topic: Presbyopia prevalence and spectacle-correction coverage were estimated by systematic review and meta-analysis of epidemiologic evidence, then modeled to expand to country, region, and global estimates., Clinical Relevance: Understanding presbyopia epidemiologic factors and correction coverage is critical to overcoming the burden of vision impairment (VI) from uncorrected presbyopia., Methods: We performed systematic reviews of presbyopia prevalence and spectacle-correction coverage. Accepted presbyopia prevalence data were gathered into 5-year age groups from 0 to 90 years or older and meta-analyzed within World Health Organization global burden of disease regions. We developed a model based on amplitude of accommodation adjusted for myopia rates to match the regionally meta-analyzed presbyopia prevalence. Presbyopia spectacle-correction coverage was analyzed against country-level variables from the year of data collection; variation in correction coverage was described best by a model based on the Human Development Index, Gini coefficient, and health expenditure, with adjustments for age and urbanization. We used the models to estimate presbyopia prevalence and spectacle-correction coverage in each age group in urban and rural areas of every country in the world, and combined with population data to estimate the number of people with near VI., Results: We estimate there were 1.8 billion people (prevalence, 25%; 95% confidence interval [CI], 1.7-2.0 billion [23%-27%]) globally with presbyopia in 2015, 826 million (95% CI, 686-960 million) of whom had near VI because they had no, or inadequate, vision correction. Global unmet need for presbyopia correction in 2015 is estimated to be 45% (95% CI, 41%-49%). People with presbyopia are more likely to have adequate optical correction if they live in an urban area of a more developed country with higher health expenditure and lower inequality., Conclusions: There is a significant burden of VI from uncorrected presbyopia, with the greatest burden in rural areas of low-resource countries., (Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the prevalence of refractive error (RE), presbyopia, spectacle coverage, and barriers to uptake optical services in Bangladesh., Method: Rapid assessment of refractive error (RARE) study following the RARE protocol was conducted in a northern district (i.e., Sirajganj) of Bangladesh (January 2010-December 2012). People aged 15-49 years were selected, and eligible participants had habitual distance and near visual acuity (VA) measured and ocular examinations were performed in those with VA<6/18. Those with phakic eyes with VA <6/18, but improving to ≥6/18 with pinhole or optical correction, were considered as RE and people aged ≥35 years with binocular unaided near vision of

Purpose: The aim was to determine the distribution of the near point of convergence (NPC) and its association with age, gender and refractive errors through a population-based study., Methods: In this cross-sectional study, samples were randomly selected from the population of Mashhad city in the northeast of Iran through stratified cluster sampling. In each of the 120 randomly selected clusters, 10 households were systematically chosen. Examinations included visual acuity testing, refractive and binocular vision examination. NPC was measured using a 6/12 single target on a Gulden fixation stick. Positive and negative fusional vergences were measured by the step method at far and near fixation distances., Results: Of the 4,453 invitees, 3,132 people participated (response rate of 70.4 per cent) and after applying the exclusion criteria, analysis was conducted on data from 2,433 individuals whose mean age was 31.2 ± 15.1 years (range: 10 to 86 years). Mean NPC was 8.59 ± 4.82 cm (range: 2 to 40 cm) in the total sample, 6.95 ± 3.87 cm in the 10-19 years age group and 13.06 ± 5.2 cm in those over 70 years. The relationships of NPC with the variables ages, gender and refractive errors (spherical equivalent) was assessed in a multiple linear regression model. Based on this model, older age (p < 0.001, coefficient = 0.106), male gender (p = 0.002, coefficient = 0.608) maintained a significant correlation with NPC, while the association with refractive error was no longer significant (p = 0.109, coefficient = 0.128) after adjusting for age and gender., Conclusion: This is the first population-based study to examine the normal ranges of NPC and also the first to describe normal values in a presbyopic population. The results of this study indicate an age-related change in NPC. These changes should be noted in the interpretation of tests for the diagnosis and treatment of problems with binocular vision., (© 2016 Optometry Australia.)

Uncorrected presbyopia is a major cause of poor near vision in the developing countries. To determine the prevalence and demographic characteristics of presbyopia among adult populations (40 years and above) in a sub-urban population, southwest Nigeria, a population-based cross-sectional study was carried out from April to May 2014. A multi-stage sampling method was used to select eligible respondents. All participants had distance visual acuity assessment done and participants with visual acuity of less than 6/6 were refracted. Near vision was then assessed at 40 cm with distance correction in place if required. Information on near vision was obtained from the participants using interviewer administered questionnaires. Data collected were analysed using SPSS version 22. A total of 440 subjects aged 40 years and above were studied. Prevalence of presbyopia was 75 % and was significantly associated with increasing age. There was higher prevalence of presbyopia among females than males (76.3 % vs. 73.5 %), though not statistically significant. Also prevalence of presbyopia was not significantly associated with educational and occupational status in the study. This study demonstrated a high prevalence of presbyopia. There is need for improved awareness on presbyopia screening and available correction in the local government.

Background: Uncorrected presbyopia can greatly impact a person's quality of life and employment prospects. Nicaragua is the poorest country in Latin America and there are no population-based reports of prevalence of presbyopia in Nicaragua., Methods: A cross-sectional population-based household survey was conducted. The sample was selected through random cluster sampling. Adults 35 years and older were enlisted through a door-to-door method using aged-based sampling. All enumerated household members 35 years and older were asked to attend a free visual acuity screening. Autorefraction was done and then uncorrected distance vision and near visual acuity were measured for all subjects. All those who had distance or near vision that was 6/12 or worse underwent a clinical examination, which included refraction at distance and near. Free spectacles were provided., Results: Of the 3,390 subjects surveyed, 37.1 per cent reported that they wore spectacles on a regular basis. A total of 1,871 (55.2 per cent) of those enumerated were examined. The prevalence of near visual impairment (6/12 [N 6] or worse) was 79.6 per cent for the 35 to 49-year-old group, 97.3 per cent for the 50 to 64-year-old group and 96.7 per cent for the 65 and over group. Of those reporting for the examination, 82.2 per cent did not have glasses. Of those examined, 10 per cent did not need spectacles, four per cent were given spectacles for distance only, 38 per cent spectacles for distance and near, 42 per cent spectacles for near only and seven per cent were referred for medical evaluation due to ocular pathology. During the refractions, 91.5 per cent were corrected to 6/12 or better at distance and 89.4 per cent were corrected to 6/12 or better at near., Conclusion: The majority of the participants who were examined did not have the spectacles that they needed. Over one-third of those participants who presented without spectacles had distance vision better than 6/12 and could be improved to good near vision with ready-made near-only spectacles., (© 2016 Optometry Australia.)

Purpose: To examine the prevalence, correlates, and impact of uncorrected presbyopia on vision-specific functioning (VF) in a multiethnic Asian population., Design: Population-based cross-sectional study., Methods: We included 7890 presbyopic subjects (3909 female; age range, 40-86 years) of Malay, Indian, and Chinese ethnicities from the Singapore Epidemiology of Eye Disease study. Presbyopia was classified as corrected and uncorrected based on self-reported near correction use. VF was assessed with the VF-11 questionnaire validated using Rasch analysis. Multivariable logistic and linear regression models were used to investigate the associations of sociodemographic and clinical parameters with uncorrected presbyopia, and its impact on VF, respectively. As myopia may mitigate the impact of noncorrection, we performed a subgroup analysis on myopic subjects only (n = 2742)., Results: In total, 2678 of 7890 subjects (33.9%) had uncorrected presbyopia. In multivariable models, younger age, male sex, Malay and Indian ethnicities, presenting distance visual impairment (any eye), and lower education and income levels were associated with higher odds of uncorrected presbyopia (all P < .05). Compared with corrected presbyopia, noncorrection was associated with worse overall VF and reduced ability to perform individual near and distance vision-specific tasks even after adjusting for distance VA and other confounders (all P < .05). Results were very similar for myopic individuals., Conclusion: One-third of presbyopic Singaporean adults did not have near correction. Given its detrimental impact on both near and distance VF, public health strategies to increase uptake of presbyopic correction in younger individuals, male individuals, and those of Malay and Indian ethnicities are needed., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Presbyopia is an age-related loss of lens accommodation resulting in difficulty in performing near task with attendant effect on the quality of life., Objective: The objective of the study was to determine the prevalence of presbyopia and presbyopic spectacle correction coverage among public school teachers in Ifo township, with a view to providing a baseline information that could be useful for advocacy and planning appropriate intervention., Study Design: The study was a descriptive, cross-sectional study., Materials and Methods: Six hundred public school teachers aged 30 years and above were examined in 25 clusters using a multistage random sampling technique with probability proportional to size. Questionnaire was used to obtain information on demographic data, sources of spectacle and barriers to spectacle use. All participants underwent a standardised protocol including visual acuity assessment (distance and near acuity), anterior and posterior segment examinations and refraction., Results: Six hundred teachers were examined with an age range of 30-61 years. The mean age was 44.7 ± 7.5 years and the male to female ratio was 1:2.2. The prevalence of presbyopia was 81.3% and 38.5% of the presbyopic teachers did not have presbyopic correction. However, the average age of onset of presbyopia was earlier in females 33 years compared to 36 years observed in males, although not statistically significant (P = 0.88). The presbyopic correction coverage was 61.5%. One hundred and eighty-six (62%) presbyopic teachers obtained their spectacle from opticians, and the main barriers to the use of near vision spectacle were lack of awareness (23.7%) and cost (13.7%)., Conclusion: This study demonstrated a high prevalence of presbyopia among public school teachers in Ifo town, South-West Nigeria, but less presbyopic spectacle correction coverage.

Background: In Tanzania, the prevalence of refractive error and presbyopia have not been comprehensively assessed, limiting appropriate planning and implementation of delivery of vision care. This study sought to determine the prevalence of refractive error and presbyopia, spectacle coverage and the barriers to uptake of refractive services in people aged 15 years and older in the Kahama district of Tanzania., Methods: A cross-sectional community-based survey was conducted using 54 randomly selected clusters. Respondents 15 years and older were interviewed and underwent standardised clinical eye examinations. Uncorrected refractive error (URE) was defined as presenting vision worse than 6/12 that could be corrected to better than 6/12 using a pinhole. Spectacle coverage was defined as the proportion of need that was met (those that improved from unaided vision with their own spectacle correction)., Results: A total of 3,230 subjects (99.75 per cent of 3,240 eligible) participated in the study with 57.2 per cent males and the median age of participants was 35 years (inter-quartile range, 24 to 49). The prevalence of visual impairment was 10.4 per cent (95% CI 9.4 to 11.4) and was lower in those who had completed their primary school education (odds ratio (OR) 0.54, 95% CI: 0.40 to 0.72) and highest in subjects 40 years and older (OR 3.17, 95% CI: 2.14 to 4.70) and farmers (OR 8.57 95% CI: 2.27 to 32.43). Refractive error prevalence was 7.5 per cent (95% CI: 6.65 to 8.54) and this was highest in participants over 40 years (OR 1.60, 95% CI: 1.14 to 2.25) and in students (OR 3.64, 95% CI: 1.35 to 9.86). Prevalence of presbyopia was 46.5 per cent (773/1,663, 95% CI: 44.34 to 48.75). Spectacle coverage for refractive error and presbyopia was 1.69% (95% CI: 0 to 3.29) and 0.42% (95% CI: 0 to 1.26), respectively., Conclusion: Uncorrected refractive error is a public health challenge in the Kahama district and sustainable service delivery and health promotion efforts are needed., (© 2014 The Authors. Clinical and Experimental Optometry © 2014 Optometrists Association Australia.)

Worldwide, more than one billion people suffer from poor vision because they do not have the eyeglasses they need. Their uncorrected refractive errors are a major cause of global disability and drastically reduce productivity, educational opportunities, and overall quality of life. The problem persists most prevalently in low-resource settings, even though prescription eyeglasses serve as a simple, effective, and largely affordable solution. In this review, we discuss barriers to obtaining, and approaches for providing, refractive eye care. We also highlight emerging technologies that are being developed to increase the accessibility of eye care. Finally, we describe opportunities that exist for engineers to develop new solutions to positively impact the diagnosis and treatment of correctable refractive errors in low-resource settings.

Everyone will experience presbyopia between the age of 45 and 50 years. The classical solution to help these patients is to offer spectacles or multifocal contact lenses. Recent developments in corneal or intraocular surgery may provide new solutions for selected patients to prevent them from always wearing glasses to read.

Background: To assess the prevalence and patterns of spectacles use in South India state of Andhra Pradesh., Design: A population-based cross sectional study., Participants: Seven thousand eight hundred subjects aged ≥40 years, sampled from one urban and two locations., Methods: Two-stage cluster random sampling method was used to enumerate 7800 subjects. Distance visual acuity and near vision were assessed. A questionnaire was used to collect information on current and previous use of spectacles, spectacles providers and type of spectacles. Among those who discontinued use of spectacles, the reasons were elicited., Main Outcome Measures: The prevalence of spectacles use and spectacle coverage., Results: In total, 7378/7800 subjects (95.0%) were examined. Among those examined, 53.6% were female, 49.5% of them aged between 40 and 49 years, and 62% of them had no education. The overall prevalence of spectacles use was 29.5% (95% confidence interval 28.5-30.4), 30.3% (95% confidence interval 29.0-31.6) in rural area compared with 27.9% (95% confidence interval 26.1-29.7) (P < 0.05) in urban location. Bifocals (72.8%) were the most common type of spectacles. Private eye clinics were the leading spectacles provider in all three regions. On applying multiple logistic regression, the odds of spectacles use increased with increasing age and were significantly higher for rural residents and those with higher levels of education. The spectacle coverage was 38.0% and 27% for refractive errors and presbyopia, respectively., Conclusions: Although prevalence of spectacles use is moderate, the spectacle coverage for both refractive errors and presbyopia is low. The strategies are required to improve the spectacle coverage in the region., (© 2013 Royal Australian and New Zealand College of Ophthalmologists.)

Background: The study is a retrospective review of the pattern of refractive errors in presbyopic patients seen in the eye clinic from January to December, 2009., Patients and Methods: The clinic refraction register was used to retrieve the case folders of all patients refracted during the review period. Information extracted includes patient's age, sex, and types of refractive error. Unaided and pin hole visual acuity was done with Snellen's or "E" Charts and near vision with Jaeger's chart in English or Hausa. All patients had basic eye examination and streak retinoscopy at two third meter working distance. The final subjective refractive correction given to the patients was used to categorize the type of refractive error., Results: There were 5893 patients, 1584 had refractive error and 644 were presbyopic. There were 289 males and 355 females (M:F= 1:1.2). Presbyopia accounted for 10.9% of clinic attendance and 40% of patients with refractive error. Presbyopia was seen in 17%, the remaining 83% required distance correction; astigmatism was seen in 41%, hypermetropia 29%, myopia 9% and aphakia 4%. Refractive error was commoner in females than males and the relationship was statistically significant (P-value = 0.017; P < 0.05 considered significant)., Conclusion: Presbyopia is common and most of the patients had other refractive errors. Full refraction is advised for all patients.

Introduction: When presbyopia (loss of accommodation of the crystalline lens with increasing age) sets in, doing near work becomes associated with headache and eye strain. Reading and writing become a challenge. Literacy levels may be low in rural communities; nevertheless some work other than reading, like sewing, sorting stone from grain and operating mobile phones, is done with dissatisfaction. This study aims to determine the prevalence of presbyopia, the unmet presbyopia need and the presbyopia correction coverage in a rural African community., Methods: A population-based cross-sectional study was carried out in a rural population aged 35 years and greater, selected by cluster random sampling. Information was sought on biodata of the participants and they were subsequently examined. Distance visual acuity for each participant was determined. Anterior and posterior segments of the eyes were examined. Objective refraction with subjective refinement was done on all subjects with distant visual acuity less than 6/6. Near visual acuity was assessed at 40 cm with distant correction in place if required. Presbyopia was defined as inability to read N8 at 40 cm or requiring an addition of at least +1.00DS to improve near vision to at least N8. Questionnaires were administered to those identified as presbyopic on source of procurement of spectacles (if they had one) and on reasons for non-procurement of presbyopic spectacles. They were also asked to rate their difficulty with various listed near work. Data entry and analysis were done using Statistical Package for the Social Sciences v16.0 and Program for Epidemiologist v4.01 software., Results: A total of 585 subjects (participation rate 81.1%) aged 35 years and greater were interviewed and examined. The prevalence of presbyopia was 63.4% (95% confidence interval (CI) 62.6-64.2%). There was increasing prevalence with increasing age. The met presbyopia need was 17.6%, unmet need was 45.8% and presbyopic correction coverage was 27.8%. The commonest reasons for not procuring presbyopic correction were 'not a priority' (21.5%) and 'cost' (21.2%)., Conclusions: The prevalence of presbyopia in this rural African community is high. Many who need presbyopic correction do not have corrective spectacles.

Purpose: To assess the prevalence of near vision impairment caused by uncorrected presbyopia and to determine the spectacle coverage for presbyopia in Durban, KwaZulu Natal, South Africa., Methods: A cross-sectional community-based survey was conducted to determine the prevalence of presbyopia in Durban. Eighteen clusters were randomly selected from the suburbs of Durban--Inanda, Ntuzuma, and KwaMashu. Adults over 35 years of age were enumerated through a door-to-door method using aged-based sampling. Respondents were interviewed and then underwent standardized clinical eye examinations. Spectacle coverage was determined. Applying multivariate logistic regressions, the strengths of association of presbyopia and spectacle coverage with the participants' demographic profile were determined., Results: A total of 2764 participants were enumerated while 1939 (70.2%) were examined with a median age of 52 years (interquartile range 45, 60). The prevalence of presbyopia was 77.0% (95% confidence interval [CI] 74.3%-79.2%), significantly higher in those 50-64 years old (OR 10.2, 95% CI 5.3-19.6) and 65-79 years old (OR 10.7, 95% CI 3.2-35.6) and significantly lower in those who had secondary and higher education (p < 0.05). The spectacle coverage for presbyopia was 4.84% (95% CI 3.35%-6.33%), significantly higher in those who were 65-79 years old (OR 4.4, 95% CI 1.5-12.9) and 50-64 years old (OR 2.6, 95% CI 1.1-6.1)., Conclusions: This study indicated that there is a high prevalence of presbyopia in the study area, with low spectacle coverage, and therefore suggests that uncorrected presbyopia is a major public health concern. The findings of this study may help in making recommendations for strategic planning for eye health intervention efforts.

Purpose: To report on the frequency of observed refractive and accommodative errors among junior high school teachers in Jakarta, Indonesia, who participated in a Helen Keller International screening, refraction and spectacle distribution program., Methods: A total of 965 teachers from 19 schools were eligible for screening; those with uncorrected distance visual acuity (VA) ≤ 6/12-3 and teachers ≥ 35 years old with uncorrected end-point print size >Jaeger (J) 6 were referred. Autorefraction and subjective refraction were performed for teachers with confirmed decreased VA. Refractive error was considered present if sphere ≤-0.75 diopters (D), sphere ≥+0.25D or cylinder ≤-0.50 D resulted in ≥ 2 lines of improvement in VA. Presbyopia was considered present if an end-point print size >J6 improved by ≥ 1 optotype with the use of a lens ≥+1.00 D., Results: Overall, 866 teachers were screened (89.7% of those eligible) with complete screening data available for 858 (99.0%), among whom 762 failed screening. Distance refraction data were available for 666 of 762 (87.4%) and near refraction data for 520 of 686 (75.8%) teachers who failed screening. Of those screened, 76.2 ± 9.0% of teachers had refractive and/or accommodative error and 57.1 ± 7.6% had uncorrected refractive and/or accommodative error. Overall and uncorrected distance refractive error affected 44.2 ± 3.7% and 36.0 ± 3.6%, respectively; overall and uncorrected presbyopia affected 66.4 ± 8.1% and 41.0 ± 6.6%, respectively., Conclusion: As defined in this program, refractive and accommodative errors were common among teachers in Jakarta.

Purpose: To assess the prevalence of presbyopia, spectacles use and spectacle correction coverage for near vision among weaving communities in Prakasam district in the South Indian state of Andhra Pradesh., Methods: A population based cross sectional study was conducted among a population aged ≥40 years. Distance visual acuity was assessed at 6 m. Near vision was assessed using N notation charts at a fixed distance of 40 cm. Presbyopia was defined as binocular unaided near vision

Purpose: To investigate economic inequality and its determinants in near vision, in a middle-aged population., Methods: In this population-based study, the presenting near vision in the better eye was investigated as the main outcome. If this vision revealed a value ≥1.6 M, the participant was considered to have presenting near vision impairment (PNVI). The effect of variables studied on PNVI was investigated using logistic regression. Economic inequality in PNVI was investigated using the Oaxaca-Blinder decomposition method., Results: PNVI in the better eye was observed in 18.2% (95% CI 16.8 to 19.6) of participants. The prevalence of PNVI in the high and low economic groups was 11.7% (95% CI 10.3 to 13.0) and 28.5% (95% CI 26.0 to 31.0), respectively. Age and education were observed as the main factors in the explained portion of this gap and were in favour of the high economic group. Gender and eye care utilisation were factors affecting the unexplained portion of this gap and were in favour of the low economic group., Conclusions: Economic inequality plays a significant role in PNVI, while age and education are among the main factors affecting this gap. The effect caused by any change in these two factors was found to have a greater effect on women with low economic status.

Centenarians represent a rare but rapidly growing segment of the oldest-old. This study presents item-level data from the Mini-Mental State Examination (MMSE) in a cross-sectional, population-based sample of 244 centenarians and near-centenarians (aged 98-108, 16% men, 21% African-American, 38% community dwelling) from the Georgia Centenarian Study (2001-2008) according to age, education, sex, race, and residential status. Multiple-Indicator Multiple-Cause (MIMIC) models were used to identify systematic domain-level differences in MMSE scores according to demographic characteristics in this age group. Indirect effects of age, educational attainment, race, and residential status were found on MMSE scores. Direct effects were limited to concentration for education and race and orientation for residential status. Mean levels of cognitive functioning in centenarians were low, with mean values below most commonly-used cutoffs. Overall scores on the MMSE differed as a function of age, education, race, and residential status, with differences in scale performance limited primarily to concentration and orientation and no evidence of interactions between centenarian characteristics. Adjusting for education was not sufficient to account for differences according to race, and adjusting for residential status was not sufficient to account for differences according to age., (© 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.)

Background: There is limited research conducted on uncorrected refractive errors, presbyopia, and spectacles use among the elderly population in residential care in developing countries such as India. We conducted a cross-sectional study among elderly in residential care to assess the spectacle coverage and spectacles usage in the south Indian state of Andhra Pradesh., Methods: All 524 residents in the 26 "homes for aged" institutions in the district were enumerated. Eye examination was performed that included visual acuity (VA) assessment for distant and near vision. A questionnaire was used to collect information on spectacles use., Results: 494/524 individuals were examined, 78% were women, and 72% had no education. The mean age of participants was 70 years. The spectacle coverage for refractive errors was 35.1% and 23.9% for presbyopia. The prevalence of current use and past use of spectacles was 38.5% (95% CI: 34.2-42.8; n = 190) and 17.2% (95% CI: 13.9-42.8), respectively., Conclusions: There is low spectacle coverage for both refractive errors and presbyopia among elderly individuals in residential care in the south Indian state of Andhra Pradesh. Appropriate service delivery systems should be developed to reach out this vulnerable group of seniors on a priority basis.