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Population Prevalence of Vision Impairment in US Adults 71 Years and Older: The National Health and Aging Trends Study
Abstract
Importance
Existing estimates of the prevalence of vision impairment (VI) in the United States are based on self-reported survey data or measures of visual function that are at least 14 years old. Older adults are at high risk for VI and blindness. There is a need for up-to-date, objectively measured, national epidemiological estimates.
Objective
To present updated national epidemiological estimates of VI and blindness in older US adults based on objective visual function testing.
Design, Setting, and Participants
This survey study presents a secondary data analysis of the 2021 National Health and Aging Trends Study (NHATS), a population-based, nationally representative panel study of Medicare beneficiaries 65 years and older. NHATS includes community-dwelling older adults or their proxies who complete in-person interviews; annual follow-up interviews are conducted regardless of residential status. Round 11 NHATS data were collected from June to November 2021, and data were analyzed in August 2022.
Interventions
In 2021, NHATS incorporated tablet-based tests of distance and near visual acuity and contrast sensitivity with habitual correction.
Main Outcomes and Measures
National prevalence of impairment in presenting distance visual acuity (>0.30 logMAR, Snellen equivalent worse than 20/40), presenting near visual acuity (>0.30 logMAR, Snellen equivalent worse than 20/40), and contrast sensitivity (>1 SD below the sample mean). Prevalence estimates stratified by age and socioeconomic and demographic data were calculated.
Results
In the 2021 round 11 NHATS sample, there were 3817 respondents. After excluding respondents who did not complete the sample person interview (n = 429) and those with missing vision data (n = 362), there were 3026 participants. Of these, 29.5% (95% CI, 27.3%-31.8%) were 71 to 74 years old, and 55.2% (95% CI, 52.8%-57.6%) were female respondents. The prevalence of VI in US adults 71 years and older was 27.8% (95% CI, 25.5%-30.1%). Distance and near visual acuity and contrast sensitivity impairments were prevalent in 10.3% (95% CI, 8.9%-11.7%), 22.3% (95% CI, 20.3%-24.3%), and 10.0% (95% CI, 8.5%-11.4%), respectively. Older age, less education, and lower income were associated with all types of VI. A higher prevalence of near visual acuity and contrast sensitivity impairments was associated with non-White race and Hispanic ethnicity.
Conclusions and Relevance
More than 1 in 4 US adults 71 years and older had VI in 2021, higher than prior estimates. Differences in the prevalence of VI by socioeconomic and demographic factors were observed. These data could inform public health planning.
... Variables of interest were chosen a priori as potential predictors of eye disease. 7,[18][19][20][21] Postcode of residence was used to derive remoteness area (major city/not major city) and the Index of Relative Socio-economic Advantage and Disadvantage decile (1-5, lower advantage/higher disadvantage vs. 6-10, higher advantage/lower disadvantage). 22 Health history included smoking and alcohol use (current/former/never). ...
... This suggests that access to eyecare may be more difficult for these groups, although uptake of healthcare services was not investigated in this study. 20,32,33 Poorer levels of eyesight were associated with comorbidities such as depression, frailty, falls, and poorer SF-12 mental and physical scores, even after adjusting for age and gender. Thus, prevention or treatment of vision loss may play an important part in reducing the burden of a range of health issues. ...
Background
We aimed to describe the self‐reported level of eyesight amongst a cohort of relatively healthy older Australian adults, and to investigate associations between poorer self‐rated eyesight and demographic, health, and functional characteristics
Methods
The ASPirin in Reducing Events in the Elderly ( ASPREE ) Longitudinal Study of Older Persons ( ALSOP ) study was embedded in a multisite trial which recruited independently living Australians from general practices (2010–2014). Self‐rated eyesight was recorded on a paper‐based questionnaire as Excellent, Good, Fair, Poor, Very poor, or Completely blind at the baseline study wave
Results
Data from 14 592 participants (aged 70–95 years, 54.61% female) were included in this cross‐sectional analysis. Eighty percent of participants reported excellent or good eyesight ( n = 11 677). People with complete blindness were precluded from enrolling but 299 participants (2.0%) reported poor or very poor eyesight, and 2616 rated their eyesight as fair (17.9%). Lower levels of eyesight were associated with being older, female, fewer years of formal education, a primary language other than English, smoking, and self‐reported macular degeneration, glaucoma, retinopathy, cataracts, and hearing problems (each p ≤ 0.021). People with lower levels of eyesight had a higher number of falls, frailty characteristics, and depressive symptoms, and lower mental and physical health functioning scores (each p < 0.001)
Conclusions
Whilst most of these healthy older Australians reported good or excellent eyesight, a notable minority reported poor or very poor eyesight, and this was associated with a range of poorer health measures. These findings support the need for additional resources to prevent vision loss and associated sequelae
Background
Existing estimates for the prevalence of dual sensory loss (vision and hearing) among older adults are either based on self‐reported measures or aggregated for older age groups. Current and detailed estimates based on objective measures are needed for public health, clinical, and policy decision‐making.
Methods
We estimated the prevalence of dual sensory loss (DSL) using National Health Aging Trends Study (NHATS) Round 11 data (2021). We restricted to community‐dwelling adults aged ≥71 years with complete sensory testing data ( N = 2579). Hearing loss was defined by a 4‐frequency (0.5, 1, 2 and 4 kHz) pure tone average for the better‐hearing ear (>25 decibel hearing level). Vision loss was defined by the presence of distance, near (logarithm of the minimum angle of resolution >0.30), or contrast sensitivity loss (log contrast sensitivity <1.55). Participants were categorized into three groups: no sensory loss, single sensory loss (vision or hearing loss), and DSL (hearing and vision). Sensory loss prevalence was estimated by age group and sociodemographic characteristics.
Results
In weighted analyses, among older Medicare beneficiaries (53% female, 7% Black, 6% Hispanic), 28% had no sensory loss and 22% had DSL. Prevalence of DSL increased with age. Most adults aged ≥90 years experienced DSL (59%), as opposed to single (39%) or no sensory loss (2%). DSL prevalence was greater among older adults with low education attainment (34%) and household income (43%). A higher proportion of older adults with a college education (17%), or from wealthier households (16%), had no sensory loss.
Conclusions
One in 5 community‐dwelling Medicare beneficiaries aged ≥71 years have DSL, increasing to 3 in 5 for those aged ≥90 years. Prevalence is higher among older adults with low education attainment and from low‐income households, characteristics associated with low treatment. Policies increasing access and affordability of vision and hearing care could benefit millions of older Americans experiencing sensory loss.
Purpose
To evaluate time trends in distance and near vision at the national and regional levels during 2000–2017 in Finland.
Methods
We used three cross‐sectional, nationwide health examination surveys representing the Finnish adult population aged 30 years or older in 2000, 2011 and 2017. Bilateral, habitual distance and near visual acuity (VA) were measured in all three surveys.
Results
The prevalence of good distance vision (VA ≥ 1.0) increased from 76.7% to 81.3% during 2000–2017 while the prevalence of weak or worse distance vision (VA ≤ 0.5) decreased from 7.6% to 3.7%. The improvements were largest among those aged 85 years and older: the prevalence of distance VA ≤ 0.5 decreased from 71.8% to 28.3%. Near vision showed improvement to a lesser extent in the total population; nevertheless, among those aged 85 years and older the prevalence of weak or worse near vision (VA ≤ 0.5) decreased from 62.3% to 27.1%. A similar positive time trend was observed in all main regions of Finland, and differences between urban and rural regions were small.
Conclusion
During the past two decades, the overall vision level has improved among the adult population. This is explained mostly by a positive shift from lower to higher vision levels among older age groups, indicating that people live longer with good or adequate vision. This positive trend showed remarkable similarity throughout different regions in Finland, highlighting the importance of equal and accessible eye care throughout the country.
Objective:
Sensory impairment has pervasive effects on older individuals' quality of life and health. Although recent research found an association between personality traits and the risk of hearing and vision impairment, data on older adults is limited, and no study has examined dual-sensory impairment. Therefore, the present study examined the prospective relationship between personality traits and risk of hearing, vision, and dual sensory impairment among older adults.
Method:
Participants were older adults aged 67 to 94 years (N = 829) from the National Health and Aging Trends Study (NHATS). Personality traits, demographic, clinical (body mass index, diabetes, and high blood pressure), and behavioral (smoking and physical activity) factors were assessed in 2013/2014. Objective measures of hearing and vision were obtained in 2021.
Results:
Controlling for demographic factors, higher conscientiousness was associated with a lower risk of hearing (OR: 0.81; 95%CI: 0.67-0.97, p = .022), vision (OR: 0.83, 95%CI: 0.71-0.97, p = .022) and dual sensory impairment (OR: 0.70, 95%CI: 0.56-0.86, p < .001). Higher openness (OR: 0.81, 95%CI: 0.68-0.97, p = .023) and neuroticism (OR: 0.74, 95%CI: 0.62-0.88, p < .001) were associated with a lower risk of hearing impairment. Clinical and behavioral covariates partially accounted for these associations.
Conclusion:
Consistent with other age-related health and cognitive outcomes, conscientiousness may be protective against sensory impairment. Surprisingly, neuroticism had a protective effect for hearing, but not vision. The findings provide novel evidence for an association between personality and sensory impairment among older adults.
Importance:
Estimates of the association between visual impairment (VI) and dementia in the US population are based on self-reported survey data or measures of visual function that are at least 15 years old. Older adults are at high risk of VI and dementia so there is a need for up-to-date national estimates based on objective assessments.
Objective:
To estimate the association between VI and dementia in older US adults based on objective visual and cognitive function testing.
Design, setting, and participants:
This secondary analysis of the 2021 National Health and Aging Trends Study (NHATS), a population-based, nationally representative panel study, included 3817 respondents 71 years and older. Data were analyzed from January to March 2023.
Intervention:
In 2021, NHATS incorporated tablet-based tests of distance and near visual acuity and contrast sensitivity (CS) with habitual correction.
Main outcomes and measures:
VI was defined as distance visual acuity more than 0.30 logMAR, near visual acuity more than 0.30 logMAR, and CS more than 1 SD below the sample mean. Dementia was defined as scoring 1.5 SDs or more below the mean in 1 or more cognitive domains, an AD8 Dementia Screening Interview Score indicating probable dementia, or diagnosed dementia. Poisson regression estimated dementia prevalence ratios adjusted for covariates.
Results:
Of 2967 included participants, 1707 (weighted percentage, 55.3%) were female, and the median (IQR) age was 76.9 (77-86) years. The weighted prevalence of dementia was 12.3% (95% CI, 10.9-13.7) and increased with near VI (21.5%; 95% CI, 17.7-25.3), distance VI (mild: 19.1%; 95% CI, 13.0-25.2; moderate, severe, or blind: 32.9%; 95% CI, 24.1- 41.8), and CS impairment (25.9%; 95% CI, 20.5-31.3). Dementia prevalence was higher among participants with near VI and CS impairment than those without (near VI prevalence ratio: 1.40; 95% CI, 1.16-1.69; CS impairment prevalence ratio: 1.31; 95% CI, 1.04-1.66) and among participants with moderate to severe distance VI or blindness (prevalence ratio: 1.72; 95% CI, 1.26-2.35) after adjustment for covariates.
Conclusions and relevance:
In this survey study, all types of objectively measured VI were associated with a higher dementia prevalence. As most VI is preventable, prioritizing vision health may be important for optimizing cognitive function.
Purpose:
To investigate the relationship between social determinants of health (SDH) with self-reported vision difficulty.
Design:
Cross-sectional, population-based analysis.
Methods:
The National Health Interview Survey (NHIS) is an annual survey based on the U.S population age 18 and older. It provides self-reported data on demographic characteristics, socioeconomic factors, health status, and health care access. The 2021 NHIS database was used in this study. Adult participants of the NHIS who responded to the vision difficulty question "Do you have difficulty seeing, even when wearing glasses or contact lenses?" were included in this analysis. The outcome of interest was self-reported vision difficulty by participants. Analysis was done through univariable and multivariable logistic regression.
Results:
Overall, there were 29,464 participants included in the analysis. Univariable logistic regression showed an increased odds of self-reported vision difficulty among female (OR 1.28; 95% CI, 1.20-1.38; p<0.001), gay, lesbian, or bisexual participants (OR 1.24; 95% CI, 1.04-1.49; p=0.02), those who possessed public compared to private insurance (OR 1.83; 95% CI, 1.69-1.99; p<0.001), those with less than a high school education (OR 1.88; 95% CI, 1.67-2.13; p<0.001), and those with an income below the poverty threshold (OR 2.22; 95% CI, 1.96-2.51-0.67; p<0.001). Multivariable analysis revealed an increased risk of vision difficulty reported amongst non-Hispanic Black participants (OR 1.65; 95% CI, 1.21-2.25; p=0.002).
Conclusions:
A multitude of sociodemographic factors are associated with self-reported vision difficulty in the United States population. Our findings emphasize the importance of considering SDH factors in clinical practice and policymaking for patients with vision loss.
Evidence conflicts on the association between sensory difficulty and depression. Few studies have examined this association using longitudinal or population-based data. We used data from Rounds 1–9 of the nationally representative National Health and Aging Trends Study to evaluate the longitudinal association between self-reported visual, hearing, and dual sensory difficulties and clinically significant depressive symptoms. Multivariable Cox regression models were used to evaluate the hazard of incident depressive symptoms. Group-based trajectory modeling identified depressive symptom trajectories (DSTs). Multinomial logistic regression was used to examine the association between sensory status and DSTs. A total of 7,593 participants were included: 56.5% were female, 53.0% were 65–74 years old, 19.0% (95% CI 17.9–20.2%) had hearing, 5.6% (4.9–6.4%) had visual, and 3.3% (2.9–3.8%) had dual sensory difficulties at baseline. Hazard ratios for depressive symptoms in those with visual, hearing, and dual sensory difficulties were 1.25 (95% CI 1.00–1.56, p = 0.047), 0.98 (95% CI 0.82–1.18, p = 0.82), and 1.67 (95% CI 1.29–2.16, p < 0.001), respectively, relative to those without sensory difficulty. A model with four trajectory groups best fit the data. Group 1 (35.8% of the sample, 95% CI: 34.1–37.4) had persistently low risk of depressive symptoms; Group 2 (44.8%, 43.4–46.3) had low but increasing risk; Group 3 (7.1%, 6.2–8.3) had moderate risk; and Group 4 (12.4%, 11.5–13.3) had moderate to high risk that increased. Compared to those without sensory difficulties, individuals with each difficulty were significantly more likely to belong to a group other than Group 1. This study reveals associations between sensory difficulties and mental health that can inform public health interventions.
Importance:
Approximately 8 million Americans self-report vision loss and blindness (VL), potentially resulting in a significant economic burden.
Objective:
Estimate the economic burden of VL in the US and by state.
Design:
Analysis of secondary data sources (American Community Survey (ACS), American Time Use Survey, Bureau of Labor Statistics, Medical Expenditure Panel Survey (MEPS), National and State Health Expenditure Accounts (N/SHEA), National Health Interview Survey (NHIS)) using attributable fraction, regression, and other methods to estimate the incremental direct and indirect 2017 costs of VL.
Participants:
People with a yes response to a question asking if they are blind or have serious difficulty seeing even when wearing glasses in the ACS, MEPS, or NHIS.
Main outcome measures:
We estimated the direct costs of medical, nursing home (NH), and supportive services; and indirect costs of absenteeism, lost household production, reduced labor force participation, and informal care by age group (0-18 years, 19-64 years, 65+ years), sex (male, female), and state in aggregate and per person with VL.
Results:
We estimated an economic burden of VL of $134.2bn, $98.7 bn in direct costs, and $35.5 bn in indirect costs. The most substantial burden components were NH ($41.8 bn), medical care services other than inpatient, ambulatory, and prescription care ($30.9 bn), and reduced labor force participation ($16.2 bn) which accounted for 66% of the total. Persons with VL incurred $16,838 per year in incremental burden. Informal care was the largest burden component for people ages 0-18 years, reduced labor force participation for people ages 19-64 years, and NH costs for people ages 65+ years. New York, Connecticut, Massachusetts, Rhode Island, and Vermont experienced the highest costs per person with VL. Sensitivity analyses indicate total burden may range between $76 and $218 bn depending on assumptions used in the model.
Conclusions and relevance:
Self-reported VL imposes a substantial economic burden on the US. Burden accrues in different ways at different ages, leading to state differences in the composition of per-person costs based on their VL population's age composition. Information on state variation can help local decision-makers better target resources to address the burden of VL.
Background
Road traffic injuries are a major public health concern and their prevention requires concerted efforts. We aimed to systematically analyse the current evidence to establish whether any aspects of vision, and particularly interventions to improve vision function, are associated with traffic safety outcomes in low-income and middle-income countries (LMICs).
Methods
We did a systematic review and meta-analysis to assess the association between poor vision and traffic safety outcomes. We searched MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials in the Cochrane Library from database inception to April 2, 2020. We included any interventional or observational studies assessing whether vision is associated with traffic safety outcomes, studies describing prevalence of poor vision among drivers, and adherence to licensure regulations. We excluded studies done in high-income countries. We did a meta-analysis to explore the associations between vision function and traffic safety outcomes and a narrative synthesis to describe the prevalence of vision disorders and adherence to licensure requirements. We used random-effects models with residual maximum likelihood method. The systematic review protocol was registered on PROSPERO, CRD-42020180505.
Findings
We identified 49 (1·8%) eligible articles of 2653 assessed and included 29 (59·2%) in the various data syntheses. 15 394 participants (mean sample size n=530 [SD 824]; mean age of 39·3 years [SD 9·65]; 1167 [7·6%] of 15 279 female) were included. The prevalence of vision impairment among road users ranged from 1·2% to 26·4% (26 studies), colour vision defects from 0·5% to 17·1% (15 studies), and visual field defects from 2·0% to 37·3% (ten studies). A substantial proportion (range 10·6–85·4%) received licences without undergoing mandatory vision testing. The meta-analysis revealed a 46% greater risk of having a road traffic crash among those with central acuity visual impairment (risk ratio [RR] 1·46 [95% CI 1·20–1·78]; p=0·0002, 13 studies) and a greater risk among those with defects in colour vision (RR 1·36 [1·01–1·82]; p=0·041, seven studies) or the visual field (RR 1·36 [1·25–1·48]; p<0·0001, seven studies). The I² value for overall statistical heterogeneity was 63·4%.
Interpretation
This systematic review shows a positive association between vision impairment and traffic crashes in LMICs. Our findings provide support for mandatory vision function assessment before issuing a driving licence.
Funding
None.
Importance
Associations between visual and global cognitive impairments have been previously documented, but there is limited research examining these associations between multiple measures of vision across cognitive domains.
Objective
To examine the association between vision and cognitive across multiple cognitive domains using multiple measures of vision.
Design, Setting, and Participants
This longitudinal cohort study used data from the Baltimore Longitudinal Study of Aging for 2003 to 2019. Participants in the current study were aged 60 to 94 years with vision and cognitive measures. Data analysis was performed from May 2020 to May 2021.
Main Outcomes and Measures
Cognitive function was measured across multiple domains, including language, memory, attention, executive function, and visuospatial ability. Cognitive domain scores were calculated as the mean of standardized cognitive test scores within each domain. Visual function was assessed using measures of visual acuity, contrast sensitivity, and stereo acuity at baseline.
Results
Analyses included 1202 participants (610 women [50.8%]; 853 White participants [71.0%]) with a mean (SD) age of 71.1 (8.6) years who were followed up for a mean (SD) of 6.9 (4.7) years. Worse visual acuity (per 0.1 logarithm of the minimal angle of resolution) at baseline was associated with greater declines in language (β, −0.0035; 95% CI, −0.007 to −0.001) and memory (β, −0.0052; 95% CI, −0.010 to −0.001) domain scores. Worse contrast sensitivity (per 0.1 log units) at baseline was associated with greater declines in language (β, −0.010; 95% CI, −0.014 to −0.006), memory (β, −0.009; 95% CI, −0.015 to −0.003), attention (β, −0.010; 95% CI, −0.017 to −0.003), and visuospatial ability (β, −0.010; 95% CI, −0.017 to −0.002) domain scores. Over the follow-up period, declines on tests of language (β, −0.019; 95% CI, −0.034 to −0.005) and memory (β, −0.032; 95% CI, −0.051 to −0.012) were significantly greater for participants with impaired stereo acuity compared with those without such impairment.
Conclusions and Relevance
These findings suggest that the association between vision and cognition differs between visual acuity, contrast sensitivity, and stereo acuity and that patterns of cognitive decline may differ by type of vision impairment, with impaired contrast sensitivity being associated with declines across more cognitive domains than other measures of visual functioning.
Importance Globally, more than 250 million people live with visual acuity loss or blindness, and people in the US fear losing vision more than memory, hearing, or speech. But it appears there are no recent empirical estimates of visual acuity loss or blindness for the US.
Objective To produce estimates of visual acuity loss and blindness by age, sex, race/ethnicity, and US state.
Data Sources Data from the American Community Survey (2017), National Health and Nutrition Examination Survey (1999-2008), and National Survey of Children’s Health (2017), as well as population-based studies (2000-2013), were included.
Study Selection All relevant data from the US Centers for Disease Control and Prevention’s Vision and Eye Health Surveillance System were included.
Data Extraction and Synthesis The prevalence of visual acuity loss or blindness was estimated, stratified when possible by factors including US state, age group, sex, race/ethnicity, and community-dwelling or group-quarters status. Data analysis occurred from March 2018 to March 2020.
Main Outcomes or Measures The prevalence of visual acuity loss (defined as a best-corrected visual acuity greater than or equal to 0.3 logMAR) and blindness (defined as a logMAR of 1.0 or greater) in the better-seeing eye.
Results For 2017, this meta-analysis generated an estimated US prevalence of 7.08 (95% uncertainty interval, 6.32-7.89) million people living with visual acuity loss, of whom 1.08 (95% uncertainty interval, 0.82-1.30) million people were living with blindness. Of this, 1.62 (95% uncertainty interval, 1.32-1.92) million persons with visual acuity loss are younger than 40 years, and 141 000 (95% uncertainty interval, 95 000-187 000) persons with blindness are younger than 40 years.
Conclusions and Relevance This analysis of all available data with modern methods produced estimates substantially higher than those previously published.
Background
The number of individuals with vision impairment worldwide is increasing because of an ageing population. We aimed to systematically identify studies describing the association between vision impairment and mortality, and to assess the association between vision impairment and all-cause mortality.
Methods
For this systematic review and meta-analysis, we searched MEDLINE (Ovid), Embase, and Global Health database on Feb 1, 2020, for studies published in English between database inception and Feb 1, 2020. We included prospective and retrospective cohort studies that measured the association between vision impairment and all-cause mortality in people aged 40 years or older who were followed up for 1 year or more. In a protocol amendment, we also included randomised controlled trials that met the same criteria as for cohort studies, in which the association between visual impairment and mortality was independent of the study intervention. Studies that did not report age-adjusted mortality data, or that focused only on populations with specific health conditions were excluded. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. We graded the overall certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations framework. We did a random-effects meta-analysis to calculate pooled maximally adjusted hazard ratios (HRs) for all-cause mortality for individuals with a visual acuity of <6/12 versus those with ≥6/12; <6/18 versus those with ≥6/18; <6/60 versus those with ≥6/18; and <6/60 versus those with ≥6/60.
Findings
Our searches identified 3845 articles, of which 28 studies, representing 30 cohorts (446 088 participants) from 12 countries, were included in the systematic review. The meta-analysis included 17 studies, representing 18 cohorts (47 998 participants). There was variability in the methods used to assess and report vision impairment. Pooled HRs for all-cause mortality were 1·29 (95% CI 1·20–1·39) for visual acuity <6/12 versus ≥6/12, with low heterogeneity between studies (n=15; τ²=0·01, I²=31·46%); 1·43 (1·22–1·68) for visual acuity <6/18 versus ≥6/18, with low heterogeneity between studies (n=2; τ²=0·0, I²=0·0%); 1·89 (1·45–2·47) for visual acuity <6/60 versus ≥6/18 (n=1); and 1·02 (0·79–1·32) for visual acuity <6/60 versus ≥6/60 (n=2; τ²=0·02, I²=25·04%). Three studies received an assessment of low risk of bias across all six domains, and six studies had a high risk of bias in one or more domains. Effect sizes were greater for studies that used best-corrected visual acuity compared with those that used presenting visual acuity as the vision assessment method (p=0·0055), but the effect sizes did not vary in terms of risk of bias, study design, or participant-level factors (ie, age). We judged the evidence to be of moderate certainty.
Interpretation
The hazard for all-cause mortality was higher in people with vision impairment compared with those that had normal vision or mild vision impairment, and the magnitude of this effect increased with more severe vision impairment. These findings have implications for promoting healthy longevity and achieving the Sustainable Development Goals.
Funding
Wellcome Trust, Commonwealth Scholarship Commission, National Institutes of Health, Research to Prevent Blindness, the Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research, Moorfields Biomedical Research Centre, Sightsavers, the Fred Hollows Foundation, the Seva Foundation, the British Council for the Prevention of Blindness, and Christian Blind Mission.
Topic
Visual impairment (VI) and cognitive impairment (CIM) are prevalent age-related conditions that impose substantial burden on the society. While the bidirectional association of VI and CIM has been hypothesized, findings have been equivocal. Hence, we conduct a systematic review and meta-analysis to examine the bidirectional relationship between VI and CIM.
Clinical Relevance
60% risk of CIM has not been well-elucidated in the literature. A bidirectional relationship between CIM and VI may provide opportunities for developing public health strategies for early detection and management of risk factors for both VI and CIM in older people.
Methods
Pubmed, Embase and Cochrane Central registers were systematically searched for observational studies, published from inception until 6 April 2020, in adults aged ≥ 40 years reporting objectively measured VI, and CIM assessment using clinically validated cognitive screening tests or diagnostic evaluation. Meta-analyses on cross-sectional and longitudinal associations between VI and CIM outcomes (any CIM assessed using screening tests, and clinically diagnosed dementia) were examined. Random effect models were used to generate pooled odds ratios (OR), and 95% confidence interval (CI). Publication bias and heterogeneity were examined using Egger’s test, meta-regression, and trim-and-fill methods.
Results
Forty studies were included (N=47,913,570). Meta-analyses confirmed that persons with VI were more likely to have CIM, with significantly higher odds [OR (95%CI)] of: (i) any CIM [cross-sectional: 2.38 (1.84-3.07); longitudinal: 1.66 (1.46-1.89)], and (ii) clinically diagnosed dementia [(cross-sectional: 2.43 (1.48-4.01); longitudinal: 2.09 (1.37-3.21)], compared to persons without VI. Significant heterogeneity was partially explained by differences in age, sex and follow-up duration. There was also some evidence that individuals with CIM, relative to cognitively intact persons, were more likely to have VI, with most papers (8/9, 89%) reporting significantly positive associations, however meta-analyses on this association could not be conducted due to insufficient data.
Conclusions
Overall, our work suggests that VI is a risk factor of CIM while further work is needed to confirm the association of CIM as a risk factor for VI. Strategies for early detection and management of both visual and cognitive impairment in older people may minimize individual clinical and public health consequences.
Summary
Background To contribute to the WHO initiative, VISION 2020: The Right to Sight, an assessment of global vision
impairment in 2020 and temporal change is needed. We aimed to extensively update estimates of global vision loss
burden, presenting estimates for 2020, temporal change over three decades between 1990–2020, and forecasts
for 2050.
Methods We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980,
to October, 2018. Only studies with samples representative of the population and with clearly defined visual acuity
testing protocols were included. We fitted hierarchical models to estimate 2020 prevalence (with 95% uncertainty
intervals [UIs]) of mild vision impairment (presenting visual acuity ≥6/18 and <6/12), moderate and severe vision
impairment (<6/18 to 3/60), and blindness (<3/60 or less than 10° visual field around central fixation); and vision
impairment from uncorrected presbyopia (presenting near vision <N6 or <N8 at 40 cm where best-corrected distance
visual acuity is ≥6/12). We forecast estimates of vision loss up to 2050.
Findings In 2020, an estimated 43·3 million (95% UI 37·6–48·4) people were blind, of whom 23·9 million (55%;
20·8–26·8) were estimated to be female. We estimated 295 million (267–325) people to have moderate and severe
vision impairment, of whom 163 million (55%; 147–179) were female; 258 million (233–285) to have mild vision
impairment, of whom 142 million (55%; 128–157) were female; and 510 million (371–667) to have visual impairment
from uncorrected presbyopia, of whom 280 million (55%; 205–365) were female. Globally, between 1990 and 2020,
among adults aged 50 years or older, age-standardised prevalence of blindness decreased by 28·5% (–29·4 to –27·7)
and prevalence of mild vision impairment decreased slightly (–0·3%, –0·8 to –0·2), whereas prevalence of moderate
and severe vision impairment increased slightly (2·5%, 1·9 to 3·2; insufficient data were available to calculate this
statistic for vision impairment from uncorrected presbyopia). In this period, the number of people who were blind
increased by 50·6% (47·8 to 53·4) and the number with moderate and severe vision impairment increased by 91·7%
(87·6 to 95·8). By 2050, we predict 61·0 million (52·9 to 69·3) people will be blind, 474 million (428 to 518) will have
moderate and severe vision impairment, 360 million (322 to 400) will have mild vision impairment, and 866 million
(629 to 1150) will have uncorrected presbyopia.
Interpretation Age-adjusted prevalence of blindness has reduced over the past three decades, yet due to population
growth, progress is not keeping pace with needs. We face enormous challenges in avoiding vision impairment as the
global population grows and ages.
Objectives
To determine the prevalence of falls, fear of falling (FoF), and activity limitation due to FoF in a nationally representative study of older adults with self‐reported vision impairment (VI).
Design
Cross‐sectional analysis of panel survey data.
Setting
National Health and Aging Trends Study, a nationally representative survey administered annually from 2011 to 2016 to U.S. Medicare beneficiaries aged 65 and older.
Participants
Respondents (N=11,558) who contributed 36,229 participant observations.
Measurements
We performed logistic regression to calculate the unadjusted and adjusted prevalence of self‐reported history of more than 1 fall in the past year, any fall in the past month, FoF, and activity limitation due to FoF in participants with and without self‐reported VI.
Results
The weighted proportion of participants reporting VI was 8.6% (95% confidence interval (CI)=8.0–9.2%). The unadjusted prevalence of more than 1 fall in the past year was 27.6% (95% CI=25.5–29.7%) in participants with self‐reported VI and 13.2% (95% CI=12.7–13.7%) in those without self‐reported VI. In respondents with self‐reported VI, the prevalence of FoF was 48.3% (95% CI=46.1–50.6%) and of FoF limiting activity was 50.8% (95%CI 47.3–54.2%), and in those without self‐reported VI, the prevalence of FoF was 26.7% (95% CI=25.9–27.5%) and of FoF limiting activity was 33.9% (95% CI=32.4–35.4%). The prevalence of all fall and fall‐related outcomes remained significantly higher among those with self‐reported VI after adjusting for sociodemographics and potential confounders.
Conclusion
The prevalence of falls, FoF, and activity limitation due to FoF is high in older adults with self‐reported VI. This is the first study to provide nationally representative data on the prevalence of fall‐related outcomes in older Americans with self‐reported VI. These findings demonstrate the need to treat avoidable VI and to develop interventions to prevent falls and fall‐related outcomes in this population.
Importance
The number of individuals with visual impairment (VI) and blindness is increasing in the United States and around the globe as a result of shifting demographics and aging populations. Tracking the number and characteristics of individuals with VI and blindness is especially important given the negative effect of these conditions on physical and mental health.
Objectives
To determine the demographic and geographic variations in VI and blindness in adults in the US population in 2015 and to estimate the projected prevalence through 2050.
Design, Setting, and Participants
In this population-based, cross-sectional study, data were pooled from adults 40 years and older from 6 major population-based studies on VI and blindness in the United States. Prevalence of VI and blindness were reported by age, sex, race/ethnicity, and per capita prevalence by state using the US Census projections (January 1, 2015, through December 31, 2050).
Main Outcomes and Measures
Prevalence of VI and blindness.
Results
In 2015, a total of 1.02 million people were blind, and approximately 3.22 million people in the United States had VI (best-corrected visual acuity in the better-seeing eye), whereas up to 8.2 million people had VI due to uncorrected refractive error. By 2050, the numbers of these conditions are projected to double to approximately 2.01 million people with blindness, 6.95 million people with VI, and 16.4 million with VI due to uncorrected refractive error. The highest numbers of these conditions in 2015 were among non-Hispanic white individuals (2.28 million), women (1.84 million), and older adults (1.61 million), and these groups will remain the most affected through 2050. However, African American individuals experience the highest prevalence of visual impairment and blindness. By 2050, the highest prevalence of VI among minorities will shift from African American individuals (15.2% in 2015 to 16.3% in 2050) to Hispanic individuals (9.9% in 2015 to 20.3% in 2050). From 2015 to 2050, the states projected to have the highest per capita prevalence of VI are Florida (2.56% in 2015 to 3.98% in 2050) and Hawaii (2.35% in 2015 and 3.93% in 2050), and the states projected to have the highest projected per capita prevalence of blindness are Mississippi (0.83% in 2015 to 1.25% in 2050) and Louisiana (0.79% in 2015 to 1.20% in 2050).
Conclusions and Relevance
These data suggest that vision screening for refractive error and early eye disease may reduce or prevent a high proportion of individuals from experiencing unnecessary vision loss and blindness, decrease associated costs to the US economy for medical services and lost productivity, and contribute to better quality of life. Targeted education and screening programs for non-Hispanic white women and minorities should become increasingly important because of the projected growth of these populations and their relative contribution to the overall numbers of these conditions.
Ophthalmologic abnormalities have been described in patients with dementia, but the extent to which poor vision and treatment for visual disorders affect cognitive decline is not well defined. Linked data from the Health and Retirement Study and Medicare files (1992-2005) were used to follow the experiences of 625 elderly US study participants with normal cognition at baseline. The outcome was a diagnosis of dementia, cognitively impaired but no dementia, or normal cognition. Poor vision was associated with development of dementia (P = 0.0048); individuals with very good or excellent vision at baseline had a 63% reduced risk of dementia (95% confidence interval (CI): 20, 82) over a mean follow-up period of 8.5 years. Participants with poorer vision who did not visit an ophthalmologist had a 9.5-fold increased risk of Alzheimer disease (95% CI: 2.3, 39.5) and a 5-fold increased risk of cognitively impaired but no dementia (95% CI: 1.6, 15.9). Poorer vision without a previous eye procedure increased the risk of Alzheimer disease 5-fold (95% CI: 1.5, 18.8). For Americans aged 90 years or older, 77.9% who maintained normal cognition had received at least one previous eye procedure compared with 51.7% of those with Alzheimer disease. Untreated poor vision is associated with cognitive decline, particularly Alzheimer disease.
Importance
Approximately 13% of US adults are affected by visual disability, with disproportionately higher rates in groups impacted by certain social determinants of health (SDOH).
Objective
To evaluate SDOH associated with severe visual impairment (SVI) to ultimately guide targeted interventions to improve ophthalmic health.
Design, Setting, and Participants
This quality improvement study used cross-sectional data from a telephone survey from the Behavioral Risk Factor Surveillance System (BRFSS) that was conducted in the US from January 2019 to December 2020. Participants were noninstitutionalized adult civilians who were randomly selected and interviewed and self-identified as “blind or having serious difficulty seeing, even while wearing glasses.”
Exposures
Demographic and health care access factors.
Main Outcomes and Measures
The main outcome was risk of SVI associated with various factors as measured by odds ratios (ORs) and 95% CIs. Descriptive and logistic regression analyses were performed using the Web Enabled Analysis Tool in the BRFFS.
Results
During the study period, 820 226 people (53.07% female) participated in the BRFSS survey, of whom 42 412 (5.17%) self-identified as “blind or having serious difficulty seeing, even while wearing glasses.” Compared with White, non-Hispanic individuals, risk of SVI was increased among American Indian/Alaska Native (OR, 1.63; 95% CI, 1.38-1.91), Black/African American (OR, 1.50; 95% CI, 1.39-1.62), Hispanic (OR, 1.65; 95% CI, 1.53-1.79), and multiracial (OR, 1.33; 95% CI, 1.15-1.53) individuals. Lower annual household income and educational level (eg, not completing high school) were associated with greater risk of SVI. Individuals who were out of work for 1 year or longer (OR, 1.78; 95% CI, 1.54-2.07) or who reported being unable to work (OR, 2.90; 95% CI, 2.66-3.16) had higher odds of SVI compared with the other variables studied. Mental health diagnoses and 14 or more days per month with poor mental health were associated with increased risk of SVI (OR, 1.87; 95% CI, 1.73-2.02). Health care access factors associated with increased visual impairment risk included lack of health care coverage and inability to afford to see a physician.
Conclusions and Relevance
In this study, various SDOH were associated with SVI, including self-identification as being from a racial or ethnic minority group; low socioeconomic status and educational level; long-term unemployment and inability to work; divorced, separated, or widowed marital status; poor mental health; and lack of health care coverage. These disparities in care and barriers to health care access should guide targeted interventions.
Maintenance of visual and auditory function is important for preventing the onset of activity limitations and preserving quality of life in later life. To date, national panel studies focused on health and aging have mostly collected subjective (self-reported) measures of visual and auditory function. The National Health and Aging Trends Study (NHATS), a study of Medicare beneficiaries ages sixty-five and older, recently developed a protocol for measuring objective visual and auditory function for its annual, in-home data collection conducted by trained interviewers. The protocol includes three vision tests—distance and near acuity and contrast sensitivity—and one hearing test—pure-tone audiometry—conducted using a tablet platform with results recorded in a scannable booklet. To identify operational issues and evaluate data quality for the proposed set of vision and hearing tests, NHATS incorporated a pilot study into its 2019 round (N = 417 participants and N = 9 interviewers). Using these pilot study data, the objectives of this paper are to: (1) describe the NHATS protocols to collect objective measures of visual and auditory function; (2) evaluate the quality of the data collected; and (3) assess whether results are influenced by interviewers. We found that respondents were highly likely to participate, with cooperation rates for each test about 90 percent. Data were high quality, with low rates of missingness, test results significantly associated with age and self-reported items, and percentages with poor vision or hearing consistent with prior population-based studies. Objective measures were more likely than self-reports to classify participants as having visual and auditory impairments and had stronger relationships with demographic correlates. Interviewer effects were small and not statistically significant in this small sample. Results of this study have demonstrated that objective visual and auditory functioning can be successfully incorporated into an interviewer-administered home-based protocol.
Purpose: Recent innovations in mobile technology for the measurement of vision present a valuable opportunity to measure visual function in non-clinical settings, such as in the home and in field-based surveys. This study evaluated agreement between a tablet-based measurement of distance and near acuity and contrast sensitivity as compared to gold-standard clinical tests.
Methods: Participants aged ≥55 years recruited from a tertiary eye clinic underwent testing with three tablet-based and corresponding gold-standard clinical measures (ETDRS distance acuity, Pelli-Robson contrast sensitivity, and MNRead near acuity). Correlation and agreement between tablet-based and clinical tests were assessed.
Results: A total of 82 participants with a mean age of 69.1 (SD = 7.6) years, and majority female (67.1%) and white (64.6%), were enrolled in this study. The mean (SD) difference between the tests (gold-standard – tablet) was −0.04 (0.08) logMAR for distance acuity, −0.11 (0.13) log units for contrast sensitivity, and −0.09 (0.12) logMAR for near acuity. 95% limits of agreement for distance acuity (-0.21, 0.12 logMAR), near acuity (-0.34, 0.14 logMAR), and contrast sensitivity (-0.36, 0.14 logCS) were also determined. The correlation between tablet-based and gold-standard tests was strongest for distance acuity (r = 0.78), followed by contrast sensitivity (r = 0.75), and near acuity (r = 0.67). The agreement between the standard and tablet-based methods did not appear to be dependent on the level of vision.
Conclusions: This study demonstrates the agreement of tablet-based and gold-standard tests of visual function in older adults. These findings have important implications for future population vision health surveillance and research.
Background
Engagement in cognitively stimulating activities is associated with decreased rates of cognitive decline in older adults. However, most cognitively stimulating tasks require good vision, potentially affecting the ability of visually impaired adults to engage in these activities. We examined the relationship between vision and participation in cognitively stimulating activities.
Methods
Data from the Health, Aging and Body Composition study (1999-2005) were analyzed. Associations between visual function (visual acuity (VA), contrast sensitivity (CS), and stereo acuity (SA) impairments) and annual rates of change in number of cognitively stimulating activities (by self-report) performed at least once a month, were examined.
Results
Analyses included 924 participants aged 75.2 ±2.8 years. At baseline, impaired CS (27%), and SA (29%) was associated with participation in fewer cognitive activities (β=-0.33, 95%CI=-0.63,-0.03; β=-0.32, 95%CI=-0.61,-0.03, respectively) while VA ( 8%) was not (β=-0.34, 95%CI=-0.81,0.13). In longitudinal models, groups with and without VA, CS, and SA impairments exhibited declines in monthly cognitive activities over time. Annual rates of decline were relatively higher in the VA (β=-0.16, 95%CI=-0.26,-0.05) and CS (β=-0.14, 95%CI=-0.19,-0.09) impaired groups than observed in the respective unimpaired groups (No VA: β=-0.12, 95%CI=-0.15,-0.10; No CS: β=-0.12, 95%CI=-0.15,-0.09), but did not achieve statistical significance. SA (β=-0.13, 95%CI=-0.17,-0.09) and no SA (β=-0.13, 95%CI=-0.16,-0.10) groups had similar rates of decline.
Conclusions
Visually impaired older adults participate in fewer cognitive activities and although participation decline is similar to the non-impaired, lower overall participation indicates a need to identify cognitively stimulating activities accessible to visually impaired older adults.
Despite the relatively high prevalence in older adults, there is an inadequate understanding of the impact of DSI on cognition and physical functioning. Concurrent vision impairment could potentially accelerate the rate of cognitive decline and dementia previously reported in individuals with hearing impairment alone.⁶ There is also a lack of research examining how to effectively treat or rehabilitate older adults with DSI. Interdisciplinary, collaborative research efforts between ophthalmologists, otolaryngologists, and geriatricians are urgently needed to investigate the impacts of DSI, as well as to examine possible treatment and rehabilitative strategies in older adults.
Correspondence: Ms Swenor, Wilmer Eye Institute, School of Medicine, The Johns Hopkins Hospital, Woods 172, 600 N Wolfe St, Baltimore, MD 21287 (bswenor@jhmi.edu).
Published Online: January 21, 2013. doi:10.1001/jamainternmed.2013.1880
Author Contributions: Ms Swenor had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Swenor, Ramulu, Friedman, and Lin. Acquisition of data: Ramulu, Willis, and Friedman. Analysis and interpretation of data: Swenor, Willis, Friedman, and Lin. Drafting of the manuscript: Swenor. Critical revision of the manuscript for important intellectual content: Swenor, Ramulu, Willis, Friedman, and Lin. Statistical analysis: Swenor, Willis, Friedman, and Lin. Study supervision: Ramulu, Friedman, and Lin.
Conflict of Interest Disclosures: Dr Lin is a consultant to Pfizer and Cochlear Corp.
Funding/Support: This work was supported by grant T32AG000247 from the National Institutes of Aging, Research to Prevent Blindness Special Scholar Award, and NIH grant EY018595. Dr Lin was supported by NIH K23DC011279 and a Triological Society/American College of Surgeons Clinician Scientist Award.
Role of the Sponsors: The funders had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.
To define normal values for the Pelli-Robson contrast sensitivity test in different age groups.
University Eye Clinic of Kuopio, Kuopio, Finland.
Contrast sensitivity was measured with the Pelli-Robson contrast sensitivity test in 87 persons (60 women and 27 men) with a mean age of 34.5 years +/- 20.8 (SD) (range 6 to 75 years). Results were studied by age group (years): 6 to 9, 10 to 19, 20 to 29, 30 to 39, 40 to 49, 50 to 59, and 60 and older. Of 163 eyes, both were healthy in 76 persons and 1 was healthy in 11. Study participants consisted of members of the staff of the Kuopio University Hospital Eye Clinic, medical students at the Kuopio University, and patients of the Strabismus and General Ophthalmology Units of the Eye Clinic and their accompanying persons. Two test distances were used: 1 m and 3 m. Eyes were tested individually; thereafter, the test was done binocularly.
There were significant differences in logarithmic contrast sensitivity values among the age groups except on the test of the left eye at 1 m. The P values for the right eye at 1 m and 3 m, left eye at 1 m and 3 m, and both eyes at 1 m and 3 m were 0.003, 0.002, 0.19, 0.043, 0.037, and 0.003, respectively. The mean test results in 1 eye varied from 1.68 in the 60 year and older group to 1.84 in the 20 to 29 and 30 to 39 year groups. Binocularly, the variation was from 1.73 in the 40 year group to 1.99 in the 30 year group.
The Pelli-Robson contrast sensitivity test is a quick and reliable method in a clinical setting. Normal values of the test can be of help in evaluating cataract patients or patients having refractive surgery.
To study the cause-specific prevalence of eye diseases causing bilateral visual impairment in Australian adults.
Two-site, population-based cross-sectional study.
Participants were aged 40 years and older and resident in their homes at the time of recruitment for the study. The study was conducted during 1992 through 1996.
The study uses a cluster stratified random sample of 4744 participants from two cohorts, urban, and rural Victoria. Participants completed a standardized interview and eye examination, including presenting and best-corrected visual acuity, visual fields, and dilated ocular examination. The major cause of vision loss was identified for all participants found to be visually impaired. Population-based prevalence estimates are weighted to reflect the age and gender distribution of the two cohorts in Victoria.
Visual impairment was defined by four levels of severity on the basis of best-corrected visual acuity or visual field: <6/18 > or =6/60 and/or <20 degrees > or =10 degrees radius field, moderate vision impairment; severe vision impairment, <6/60 > or =3/60 and/or <10 degrees > or =5 degrees radius field; and profound vision impairment <3/60 and/or <5 degrees radius field. In addition, less-than-legal driving vision, <6/12 > or =6/18, and/or homonymous hemianopia were defined as mild vision impairment. In Australia, legal blindness includes severe and profound vision impairment.
The population-weighted prevalence of diseases causing less-than-legal driving or worse impairment in the better eye was 42.48/1000 (95% confidence interval [CI], 30.11, 54.86). Uncorrected refractive error was the most frequent cause of bilateral vision impairment, 24.68/1000 (95% CI, 16.12, 33.25), followed by age-related macular degeneration (AMD), 3.86/1000 (95% CI, 2.17, 5.55); other retinal diseases, 2.91/1000 (95% CI, 0.74, 5.08); other disorders, 2.80/1000 (95% CI, 1.17, 4.43); cataract, 2.57/1000 (95% CI, 1.38, 3.76); glaucoma, 2.32/1000 (95% CI, 0.72, 3.92); neuro-ophthalmic disorders, 1.80/1000 (95% CI, 0, 4.11); and diabetic retinopathy, 1.53/1000 (95% CI, 0.71, 2.36). The prevalence of legal blindness was 5.30/1000 (95% CI, 3.24, 7.36). Although not significantly different, the causes of legal blindness were uncorrected refractive errors, AMD, glaucoma, other retinal conditions, and other diseases.
Significant reduction of visual impairment may be attained with the application of current knowledge in refractive errors, diabetes mellitus, cataract, and glaucoma. Although easily preventable, uncorrected refractive error remains a major cause of vision impairment.
To report the prevalence of blindness and visual impairment and the contribution of uncorrected refractive error to visual loss, in a population-based sample of Mexican Americans aged 40 and older.
Proyecto VER is a population-based study of blindness and visual impairment in Mexican Americans in Arizona. Block groups in Tucson and Nogales were randomly selected with probability proportional to the size of the Mexican-American population aged 40 and older. Participants had a complete ophthalmic evaluation, including assessment of presenting and best corrected visual acuity using standardized procedures. Those with presenting visual acuity worse than 20/30 had refraction to determine best corrected vision. A home questionnaire and a clinic examination provided data on education, perception of visual impairment, income, and acculturation.
The prevalence of presenting visual acuity worse than 20/40 was 8.2%, with uncorrected refractive error accounting for 73% of the impaired acuity. In multivariate models comparing those who improved two or more lines on the acuity chart with proper refraction with those who had adequate optical correction, uncorrected refractive error showed a strong association with age, less than 13 years of education (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.5-2.0), low acculturation index (OR 1.3, CI 1.1-1.3), lack of insurance coverage (OR 1.4, CI 1.1-1.7), and not having seen an eye-care provider in the past 2 years (OR 2.5, CI 2.1-3.0). Prevalence of best corrected acuity worse than 20/40 increased from 0.3% in those aged 40 to 49 years to 18% in those aged 80 years or more.
Visual loss in this Mexican-American population is higher than has been reported in whites and is comparable to that in African Americans. Almost three quarters of those with visual acuity impairment would improve with optical correction. Socioeconomic factors that are probable markers of limited access to health care services were associated with uncorrected refractive error. These data suggest that education programs and interventions to improve access to eye care could significantly decrease the burden of visual loss among Mexican Americans.
The prevalence of visual impairment in the US public has not been surveyed nationally in several decades.
To estimate the number of US individuals aged 12 years or older who have impaired distance vision due to uncorrected refractive error.
The National Health and Nutrition Examination Survey (NHANES), using a multistage probability sampling design, included a vision evaluation in a mobile examination center. Visual acuity data were obtained from 13,265 of 14,203 participants (93.4%) who visited the mobile examination center in 1999-2002. Visual impairment was defined as presenting distance visual acuity of 20/50 or worse in the better-seeing eye. Visual impairment due to uncorrected refractive error was defined as (presenting) visual impairment that improved, aided by automated refraction results, to 20/40 or better in the better-seeing eye.
Presenting distance visual acuity (measured with usual corrective lenses, if any) and distance visual acuity after automated refraction.
Overall, 1190 study participants had visual impairment (weighted prevalence, 6.4%; 95% confidence interval [CI], 6.0%-6.8%), and of these, 83.3% could achieve good visual acuity with correction (95% CI, 80.9%-85.8%). Extrapolating these findings to the general US population, approximately 14 million individuals aged 12 years or older have visual impairment (defined as distance visual acuity of 20/50 or worse), and of these, more than 11 million individuals could have their vision improved to 20/40 or better with refractive correction.
Visual impairment due to uncorrected refractive error is a common condition in the United States. Providing appropriate refractive correction to those individuals whose vision can be improved is an important public health endeavor with implications for safety and quality of life.