According to the World Health Organization, between 2015 and 2050, the proportion of the global population aged over 60 years will nearly double (from 12 to 22%) (1). This unprecedented demographic shift means that age-related conditions, such as presbyopia, will affect an ever-growing number of people in the coming decades. Within the Global Burden of Disease (GBD) framework, near vision loss (NVL) denotes near-vision impairment attributable to uncorrected presbyopia, whereas presbyopia refers to age-related loss of accommodation. This phenomenon can be attributed to age-related stiffening of the lens, which impedes optimal near vision (2). Current estimates indicate that this condition affects more than 1.8 billion individuals worldwide (3). Individuals with uncorrected NVL frequently encounter challenges while performing close-up tasks. Research indicates that 50%–70% of individuals with functional presbyopia experience difficulties with near work, resulting in absenteeism, reduced work efficiency, and a decline in economic productivity (4–6). From an economic standpoint, the absence of treatment for presbyopia significantly contributes to productivity losses, with annual vision-related expenditures of $25.4 billion (7). More recent analyses focusing on low- and middle-income countries and territories (where the majority of NVL cases reside) found more than $54.1 billion per year in productivity loss in these regions alone due to uncorrected presbyopia (8). Evidence from qualitative studies and limited quantitative research indicates that presbyopia exerts a substantial impact on quality of life across domains such as activity limitations, emotional well-being, social status, and economic standing—an effect that is frequently underestimated (9–13).

Interventions that correct presbyopia—including optical correction (spectacles, contact lenses), surgical approaches (corneal or lens-based procedures), and pharmacological therapies—can reduce the burden of NVL (14, 15). Presbyopia-related near-vision impairment can be effectively corrected with low-cost optical interventions (e.g., ready-made or custom near spectacles, bifocal/multifocal designs), and widespread correction substantially reduces population-level NVL; however, unmet needs remain considerable (16). In low-income regions, only 6%–45% of individuals requiring correction receive adequate care (17, 18). The highest reported correction rates were observed in Los Angeles, USA (87.4%) (19), followed by Trinidad and Tobago (52.6%) (20), and Parintins, Brazil (31.4%) (21, 22). A randomized trial in rural India demonstrated that tea pickers aged ≥40 years with corrected NVL achieved a 22% increase in productivity (and income growth) compared with their uncorrected counterparts (23). These findings highlight the urgency of focusing on NVL, which should not be viewed merely as a biological inevitability but as a modifiable determinant of health equity.

This study aimed to systematically address critical gaps in understanding the global burden of NVL by integrating socioeconomic development, demographic aging, and health policy dimensions. While previous studies have inadequately disentangled the contributions of population growth, aging, and epidemiological shifts to the NVL burden or accounted for regional disparities in intervention efficacy, our analysis leveraged the GBD 2021 dataset across 204 countries and territories to fill these voids. Employing advanced methodologies, including decomposition analysis to isolate demographic and epidemiological drivers, Bayesian age-period-cohort (BAPC) models for granular future projections, and frontier analysis to quantify sociodemographic index (SDI)-linked inequities, we mapped the evolving burden from 1990 to 2021 and identified context-specific mitigation strategies. This study resolves the limitations of fragmented regional assessments and simplistic forecasting, thereby providing a comprehensive framework for prioritizing interventions—such as optical subsidy expansion and workplace vision policy reforms—particularly in underserved low-resource settings where diagnostic and care gaps persist.

This study conducted a systematic analysis of the GBD 2021 data on NVL and its epidemiological determinants, integrating the dimensions of socioeconomic development, population aging, and healthcare policies to inform evidence-based optimization of intervention strategies. The results demonstrated a substantial escalation in the global NVL burden, with the number of prevalent cases increasing dramatically from 428.0 million to 1.155 billion. Population growth accounted for 65.3% of the DALY variation, whereas the contribution of population aging was negligible (−4.4%). Furthermore, females exhibited a persistently higher ASPR than males. These findings suggest that the global burden of NVL is predominantly attributable to population growth and shows strong associations with sex disparities, socioeconomic development status, and regional healthcare policy frameworks.

Globally, NVL, predominantly uncorrected presbyopia, constitutes a major proportion of vision impairment. In 2019, DALYs from NVL accounted for 21.7% of the DALYs due to blindness and vision loss, approaching cataracts (29.6%), uncorrected distance refractive error (29.1%), far exceeding glaucoma (3.3%), and age-related macular degeneration (2.5%) (26). Uncorrected presbyopia imposes a population health burden comparable to that of major blinding diseases through limitations in reading, close work, and daily activities, underscoring the need to prioritize simple near-vision correction.

The analysis demonstrated significantly elevated prevalence rates and DALY burdens of NVL among females compared with males, aligning with established epidemiological patterns in ophthalmology (2, 27–30). This disparity is hypothesized to result from a confluence of biological determinants and structural health inequities. First, longer life expectancy leads to greater cumulative exposure to presbyopia, thereby resulting in a higher number of older women at risk of near-vision impairment (NVL) in the population (31). Second, unequal access to eye care between sexes is likely to play a role (32). In many low-resource settings, women face greater barriers to obtaining refractive correction due to lower incomes, less decision-making power, or cultural norms that prioritize men’s health needs (33–35). Third, cyclic estrogen variations such as those during menstruation (36), gestation (37), and menopause (38) have been mechanistically linked to refractive instability through corneal biomechanical alterations. Accordingly, gender-responsive delivery models that integrate refraction and on-site subsidized or free spectacle provision into women’s health services and community organizations can increase coverage, lower access costs, and prevent exclusion.

Notably, the epidemiological transition manifested as a 5-year advancement in the peak prevalence age, shifting from 55–59 years in 1990 to 50–54 years by 2021. One hypothesis is that prolonged near work (such as extensive use of smartphones, computers, and other digital devices) may be placing greater accommodative demands on the eyes from a younger age, leading to “accommodation fatigue” or earlier functional presbyopia (39). Modern lifestyles may accelerate the manifestation of presbyopic symptoms. Increased near work exposure could further amplify the global NVL burden, possibly affecting people in their 40s or late 30s with symptomatic near-vision strain.

This study elucidated the complex association between SDI and NVL disease burden. At the regional level, the SDI demonstrated an inverted L-shaped relationship with both NVL prevalence and DALYs, characterized by three distinct phases: a steep increase in disease burden at lower SDI values, decelerated growth at moderate SDI levels, and eventual stabilization in high-SDI regions. These patterns correlate with global disparities in refractive care, where over 90% of individuals in rural areas of low- and middle-income countries lack corrective interventions compared with about 40% in urban or high-income settings (19). It is important to note that this socioeconomic gradient manifests not only in healthcare resource allocation but may also influence disease progression through multiple risk exposure pathways. A systematic association exists between lower socioeconomic status and factors such as uncorrected refractive errors, nutritional deficiencies, elevated ultraviolet radiation exposure, air pollution exposure, and higher prevalence of systemic comorbidities (40–42). The synergistic interactions between these factors likely exacerbate geographic disparities in the prevalence of NVL. Our analysis identifies SDI > 0.6 as a critical threshold for achieving substantial NVL burden reduction through basic health care coverage.

Notably, absolute inequalities in the NVL burden remain stark: the magnitude of absolute inequality between the highest and lowest SDI regions has widened from 10.19 (1990) to 31.96 (2021), driven by population growth (65.3% contribution) and delayed corrective interventions in low-SDI settings. Longitudinal data show that although low- to middle-SDI countries and territories have made significant progress in reducing blindness over the last three decades, persistent health inequalities remain evident (43). The factors contributing to this disparity are multifaceted. Rapid population growth and aging in low-SDI regions have greatly increased the number of NVL cases. Second, the persistent underprovision of vision correction services within these regions compounded this issue. Countries and territories with high SDI have been more effective in addressing presbyopia (through better health care access and higher eyeglass uptake). Access to near-vision correction in low-SDI settings is constrained by interrelated economic, cultural, and geographic barriers. Economically, even low-cost spectacles are unaffordable where health spending is predominantly out of pocket and subsidy mechanisms are absent. For instance, in rural India, cost is the most commonly cited reason for not obtaining glasses despite documented productivity gains from near-vision correction (44). Individuals earning less than $53.0 per month versus more than $107.1 per month had 48-fold higher odds of purchasing spectacles, an income gradient that likely contributed to the high burden of uncorrected presbyopia in low- and middle-income countries and territories (45). Financial constraints are compounded by a tendency to prioritize other household needs over ocular health. Culturally, low awareness and limited health literacy foster perceptions that presbyopia is an inevitable consequence of aging rather than a treatable impairment, and the stigma surrounding spectacle wear (e.g., beliefs that glasses weaken the eyes or denote frailty) deters uptake, as reported in Nepal (10). Geographic disparities further impede access because eye care services and optical shops are concentrated in urban centers, leaving rural populations underserved (46). Overall, these barriers—financial, informational, and service availability—help explain why presbyopia remains substantially undercorrected in low-SDI regions.

Based on data from 1990 to 2021, a frontier analysis using DALYs and SDI highlighted the significant potential for reducing the burden of NVL in different countries and territories. South Africa, India, and 15 other countries and territories had the largest gaps in improvement potential, reflecting the uneven distribution of the global disease burden, with low- and middle-income areas struggling because of limited resources. Interestingly, some high-SDI regions also showed a high improvement potential, indicating the need for an in-depth exploration of health system vulnerabilities in middle- and high-SDI countries and territories. Notably, even within these high-income settings, direct costs—including expenses related to accessing eye care services, transportation for appointments, and pharmaceutical interventions—remain critical barriers to equitable visual health, particularly for populations in rural areas or with lower socioeconomic status (47). Targeted policies to address disparities in access to vision care in high-SDI countries and territories are required. Priority actions include expanding insurance coverage for refractive services, deploying mobile clinics in underserved rural areas, and subsidizing transport for low-income patients to secure equitable access for marginalized groups.

Decomposition analysis revealed heterogeneous drivers underlying the evolving disease burden of NVL. Globally, population growth accounted for 65.3% of the DALY changes, far exceeding the contributions of aging (−4.4%) and epidemiological shifts (39.2%). This predominance is closely tied to the cumulative burden of uncorrected cases in low-SDI regions owing to insufficient coverage of refractive services. In sub-Saharan Africa, the population-driven effect exceeds 100%, whereas epidemiological changes exhibit a slightly negative impact. Notably, studies indicate that the accelerated development of optometric education in sub-Saharan Africa has enhanced the availability of a skilled workforce for delivering quality eye care, thereby improving access to refractive services (48). These findings underscore that while progress in optometric education has partially alleviated service gaps in the region, there is an urgent need to synchronize primary eye care network development with persistently high population growth rates to address the long-term imbalance between demographic expansion and resource provision. The BAPC projections indicated a steepening trajectory of the NVL burden. This escalation reflects multiple factors: population growth in low-SDI regions, accelerated aging in middle-income regions, and persistent under-correction of refractive errors. Low-SDI regions face dual pressures of population expansion and lagging service coverage.

A coordinated package—comprising mass provision of low-cost spectacles, community outreach, integration into primary care, and telemedicine-enabled screening—can deliver rapid and scalable gains in closing the near-vision care gap. A priority policy is the large-scale provision of low-cost spectacles. Given the minimal unit costs for ready-made readers, governments and nongovernmental organizations can efficiently deliver them to high-need communities through subsidies or free distribution. Even modest investments are likely to yield substantial returns by restoring near vision for work, learning, and daily functioning, thereby improving productivity and quality of life (23). Community-based programs are critical delivery channels for near vision care. Regular screening camps in rural settings and the incorporation of near-vision checks into existing outreach enable the rapid identification of presbyopia and same-day dispensing of spectacles. These models reduce geographic access barriers and reach populations that are otherwise missed by providing services directly to underserved communities. Integrating presbyopia screening and treatment into primary care is essential for the sustainability and equitable reach of the program. Consistent with the World Health Organization’s framework of integrated, people-centered eye care (IPEC), routine primary care visits should include a simple near-vision test and on-site dispensing of appropriate ready-made spectacles with referral for complex refractive needs. Embedding these steps into routine encounters identifies individuals who would not otherwise seek eye care because of their low awareness or competing priorities (32). Telemedicine- and smartphone-based examinations can narrow the refractive care gap, particularly in primary care and community settings. Low-cost applications and peripherals enable remote vision screening and basic ocular assessment with minimal infrastructure (49). Currently, smartphone-based mobile refractors are available. Luo et al. (50) validated a smartphone application for estimating myopic refractive error in 113 participants with ≤1.75 D astigmatism, demonstrating strong agreement with clinical refraction and autorefractor measurements and good test–retest reliability. For presbyopia, self-administered near-vision and simplified refraction tests can triage users into ready-made spectacles, with virtual optometrist follow-ups when necessary. When integrated into routine workflows, these tools achieve screening-level accuracy, extend reach to underserved areas, and support task sharing.

Although this study provided critical insights into the global epidemiology of NVL, it had three principal limitations. First, global NVL estimates are limited by cross-country differences in assessment and reporting, and widespread underdiagnosis, which together may lead to variability and underestimation. For example, the definition of “near vision loss” might not be perfectly uniform—some studies define it by the inability to read standard near print at 40 cm, while others define it by a certain dioptric requirement. We assumed comparability based on GBD standardized adjustments; however, residual differences may remain. Second, NVL is often underdiagnosed in communities that lack regular eye examinations. Many individuals do not realize that their vision can be corrected, and thus never report or seek care for near-vision difficulties. This underdiagnosis means that our NVL burden estimates might be conservative in some low-access settings because undetected cases would not have been counted in official data. Third, the temporal scope precluded a comprehensive assessment of the COVID-19 pandemic’s post-2020 impact, which has likely exacerbated healthcare disparities and disrupted refractive care continuity among vulnerable populations. Furthermore, the correlations observed in previous studies, such as the relationship between SDI and NVL prevalence, may not necessarily imply causality. In addition to these empirical and scope-related constraints, we note a further conceptual caveat related to our reliance on DALYs. Although DALYs remain a widely used and informative metric for cross-population comparison, disability scholars and public health ethicists have cautioned that DALY frameworks can inadvertently encode ableist assumptions by equating disability with diminished quality or value of life (51, 52). Accordingly, DALY-based estimates may understate the worth of years lived with disability and risk skewing priority-setting toward states deemed “healthier” by construction (53). Because our analysis relies on DALYs, our interpretations inherit this normative limitation. We believe this addition enhances the ethical transparency and conceptual balance of our study.

Looking ahead, reducing NVL will depend on implementation research that evaluates scalable service delivery packages across SDI strata, such as the mass provision of low-cost spectacles, community outreach, primary care integration, and teleophthalmology, while concurrently strengthening supply chain resilience and eye health workforce capacity. Priorities include standardizing near-vision metrics and surveillance systems, validating AI-enabled screening in real-world settings, and embedding explicit equity targets in financing mechanisms (e.g., insurance expansion and transport subsidies). Linking cost-effectiveness evidence to DALY reduction can reveal the benefits of package design. Co-designed approaches involving women and rural communities are essential for closing persistent access gaps.

Our analysis indicates that the global burden of NVL is driven primarily by population growth, with low SDI regions disproportionately affected because uncorrected cases accumulate under inadequate refractive service coverage. Women exhibited significantly higher ASPR than men, highlighting the disparities in sex-specific risk profiles and in societal resource allocation. These findings support a tiered response in which priority should be given to expanding essential refractive services and implementing gender-responsive policies (e.g., community-based vision screening for women) to reduce inequities and slow the emerging trend toward an earlier onset. Correcting presbyopia can yield substantial economic and social benefits through productivity and quality-of-life gains, underscoring the urgency of expanding access to near-vision services.