The impact of accelerating population aging on service industry development: Evidence from China.

The demographic structure is an important factor influencing the development of the services industry. As the country with the world's most serious aging problem, China's service industry structure is likely to undergo profound changes in response to the rapid demographic transition. Therefore, this paper examines the effect of population aging on the development of the service industry in the context of China's accelerating population aging. The study found that: (1) Population aging has a significant "inverted U" effect on the development of the services industry. (2) The impact of population aging on the development of the service industry has obvious regional and industry heterogeneity. The study of regional heterogeneity found that population aging in economically developed regions has a more obvious effect on the development of the service industry than in economically less developed regions. Industry heterogeneity studies found that population aging has an obvious promotional effect on the development of medical and other rigid demand industries, while the effect on other non-rigid demand industries is not significant. (3) The threshold effect test found that when the degree of population aging exceeds the threshold, the stimulating effect of population aging on the development of the services industry is no longer significant. The research in this paper provides useful insights into the likely response to changes in the industrial structure of the services industry, and offers some implications for countries with similar demographic profiles to China.

Persistence of severe global inequalities in the burden of blindness and vision loss from 1990 to 2019: findings from the Global Burden of Disease Study 2019.

AIMS: To assess the global burden and economic inequalities in the distribution of blindness and vision loss between 1990 and 2019. METHODS: A secondary analysis of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019. Data for disability-adjusted life-years (DALYs) due to blindness and vision loss were extracted from the GBD 2019. Data for gross domestic product per capita were extracted from the World Bank database. Slope index of inequality (SII) and concentration index were computed to assess absolute and relative cross-national health inequality, respectively. RESULTS: Countries with high, high-middle, middle, low-middle and low Socio-demographic Index (SDI) had decline of age-standardised DALY rate of 4.3%, 5.2%, 16.0%, 21.4% and 11.30% from 1990 to 2019, respectively. The poorest 50% of world citizens bore 59.0% and 66.2% of the burden of blindness and vision loss in 1990 and 2019, respectively. The absolute cross-national inequality (SII) fell from -303.5 (95% CI -370.8 to -236.2) in 1990 to -256.0 (95% CI -288.1 to -223.8) in 2019. The relative inequality (concentration index) for global blindness and vision loss remained essentially constant between 1991 (-0.197, 95% CI -0.234 to -0.160) and 2019 (-0.193, 95% CI -0.216 to -0.169). CONCLUSION: Though countries with middle and low-middle SDI were the most successful in decreasing burden of blindness and vision loss, a high level of cross-national health inequality persisted over the past three decades. More attention must be paid to the elimination of avoidable blindness and vision loss in low-income and middle-income countries.

Assessment of Peripapillary Retinal Nerve Fiber Layer Optical Density Ratios in Healthy Eyes Using Optical Coherence Tomography with Different Analytical Radii.

PURPOSE: To explore the characteristics and determinants of peripapillary retinal nerve fiber layer (RNFL) optical density (OD) by optical coherence tomography (OCT) in healthy eyes with varied analytical radii. METHODS: Peripapillary OCT scans centered at the optic disc of 150 eyes from 150 healthy subjects (64 males and 86 females) were included. Under 5 analytical circles with different radii (1.45 mm, 1.7 mm, 1.95 mm, 2.2 mm and 2.45 mm), the circumpapillary circular cross-sectional images were exported for further analysis using Image J. Peripapillary RNFL and retinal pigment epithelium (RPE) OD in different quadrants and clock-hours were obtained. RNFL optical density ratio (ODR) was then calculated as RNFL OD divided by RPE OD. A linear mixed-effects model analysis was performed to assess the relationship between RNFL ODR and analytical radius, accounting for axial length, age, spherical equivalent, thickness and image score. RESULTS: The RNFL ODRs had a double-hump pattern with peaks in the superior and inferior quadrants and troughs in the temporal and nasal areas. In the linear mixed-effects model analysis, a trend of decreasing mean RNFL ODR with increasing analytical radius was found (0.9227 ± 0.0689, 0.9063 ± 0.0620, 0.8916 ± 0.0552, 0.8729 ± 0.0553 and 0.8575 ± 0.0564 respectively, p = 0.034). RNFL ODR values was negatively correlated with age (p < 0.001), positively correlated with corresponding RNFL thickness (p < 0.001). No significant correlation was found between RFNL ODR and image score, axial length and spherical equivalent. CONCLUSIONS: RNFL ODR profile showed a comparable double-hump configuration with RNFL thickness. RNFL ODR values tended to decrease with larger analytical circles and older age, and increase with corresponding RNFL thickness. These factors should be considered when interpreting RNFL ODR in glaucoma assessment.

Global, regional, and national burden of multiple sclerosis from 1990 to 2019: Findings of global burden of disease study 2019.

Background: The global rising prevalence and incidence of multiple sclerosis (MS) has been reported during the past decades. However, details regarding the evolution of MS burden have not been fully studied. This study aimed to investigate the global, regional, and national burden and temporal trends in MS incidence, deaths, and disability-adjusted life years (DALYs) from 1990 to 2019 using the age-period-cohort analysis. Methods: We performed a secondary comprehensive analysis of incidence, deaths, and DALYs of MS by calculating the estimated annual percentage change from 1990 to 2019 obtained from the Global Burden of Disease (GBD) 2019 study. The independent age, period, and birth cohort effects were evaluated by an age-period-cohort model. Results: In 2019, there were 59,345 incident MS cases and 22,439 MS deaths worldwide. The global number of incidences, deaths, and DALYs of MS followed an upward trend, whereas the age-standardized rates (ASR) slightly declined from 1990 to 2019. High socio-demographic index (SDI) regions had the highest ASR of incidences, deaths, and DALYs in 2019, while the rate of deaths and DALYs in medium SDI regions are the lowest. Six regions which include high-income North America, Western Europe, Australasia, Central Europe, and Eastern Europe had higher ASR of incidences, deaths, and DALYs than other regions in 2019. The age effect showed that the relative risks (RRs) of incidence and DALYs reached the peak at ages 30-39 and 50-59, respectively. The period effect showed that the RRs of deaths and DALYs increased with the period. The cohort effect showed that the later cohort has lower RRs of deaths and DALYs than the early cohort. Conclusion: The global cases of incidence, deaths, and DALYs of MS have all increased, whereas ASR has declined, with different trends in different regions. High SDI regions such as European countries have a substantial burden of MS. There are significant age effects for incidence, deaths, and DALYs of MS globally, and period effects and cohort effects for deaths and DALYs.

Assessment of the influence of keratometry on intraocular lens calculation formulas in long axial length eyes.

PURPOSE: Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes. METHODS: Retrospective case series. A total of 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average), and all the eyes were underwent phacoemulsification cataract surgery with Rayner (Hove, UK) 920H IOL implantation. Prediction errors (PE) were compared between different formulas to assess the accuracy of different formulas. Multiple regression analysis was performed to investigate factors associated with the PE. RESULTS: The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only. CONCLUSIONS: Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.

Assessment of Generative Adversarial Networks for Synthetic Anterior Segment Optical Coherence Tomography Images in Closed-Angle Detection.

Purpose: To develop generative adversarial networks (GANs) that synthesize realistic anterior segment optical coherence tomography (AS-OCT) images and evaluate deep learning (DL) models that are trained on real and synthetic datasets for detecting angle closure. Methods: The GAN architecture was adopted and trained on the dataset with AS-OCT images collected from the Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, synthesizing open- and closed-angle AS-OCT images. A visual Turing test with two glaucoma specialists was performed to assess the image quality of real and synthetic images. DL models, trained on either real or synthetic datasets, were developed. Using the clinicians' grading of the AS-OCT images as the reference standard, we compared the diagnostic performance of open-angle vs. closed-angle detection of DL models and the AS-OCT parameter, defined as a trabecular-iris space area 750 µm anterior to the scleral spur (TISA750), in a small independent validation dataset. Results: The GAN training included 28,643 AS-OCT anterior chamber angle (ACA) images. The real and synthetic datasets for DL model training have an equal distribution of open- and closed-angle images (all with 10,000 images each). The independent validation dataset included 238 open-angle and 243 closed-angle AS-OCT ACA images. The image quality of real versus synthetic AS-OCT images was similar, as assessed by the two glaucoma specialists, except for the scleral spur visibility. For the independent validation dataset, both DL models achieved higher areas under the curve compared with TISA750. Two DL models had areas under the curve of 0.97 (95% confidence interval, 0.96-0.99) and 0.94 (95% confidence interval, 0.92-0.96). Conclusions: The GAN synthetic AS-OCT images appeared to be of good quality, according to the glaucoma specialists. The DL models, trained on all-synthetic AS-OCT images, can achieve high diagnostic performance. Translational Relevance: The GANs can generate realistic AS-OCT images, which can also be used to train DL models.

The impact of prenatal exposure to PM2.5 on childhood asthma and wheezing: a meta-analysis of observational studies.

With the accelerated pace of economic development and modernization, air pollution has become one of the most focused public health problems. However, the impact of particulate matter exposure during pregnancy on childhood asthma and wheezing remains controversial. We performed this meta-analysis to explore the relationship between prenatal exposure to PM2.5 and childhood asthma and wheezing. Candidate papers were searched on PubMed, Web of Science, Embase, and Cochrane Library before July 15, 2019. The main characteristics of the included studies were extracted, and the quality was evaluated by the Newcastle-Ottawa Scale (NOS). A sensitivity analysis was performed to assess the impact of individual studies on the combined effects. The Egger and Begg tests were conducted to examine the publication bias. Nine studies were included in the final analysis. Prenatal exposure to PM2.5 significantly increased the risk of childhood asthma and wheezing (OR = 1.06, 95% CI 1.02-1.11; per 5 µg/m3). Maternal exposure was more strongly related to childhood asthma and wheezing before age 3 (OR = 1.15, 95% CI 1.00-1.31; per 5 µg/m3) than after (OR = 1.04, 95% CI 1.00-1.09; per 5 µg/m3). Children in developed countries showed more severe effects (OR = 1.14, 95% CI 1.02-1.27; per 5 µg/m3). Children who were born to mothers with higher levels of prenatal exposure were at higher risk of asthma and wheezing (OR = 1.07, 95% CI 1.02-1.13; per 5 µg/m3). This meta-analysis indicated that the impact of PM2.5 on childhood asthma and wheezing begins as early as utero, so regulating pollutant emission standards and strengthening prenatal protection are crucial to maternal and child health.

Preliminary Assessment of Intense Pulsed Light Treatment on the Upper Eyelids for Meibomian Gland Dysfunction.

Objective: To conduct a preliminary assessment of the intense pulsed light (IPL) treatment on the upper eyelid. Background: IPL therapy is an effective therapy for meibomian gland dysfunction (MGD). The normal treatment region includes the skin below the lower eyelids and both temporal parts, but not the upper eyelid. Methods: Thirty patients with mid-to-severe dry eye disease caused by MGD were selected and randomly divided into two groups. Fifteen controls in group A received normal IPL treatment. Fifteen patients in Group B underwent additional IPL treatment on the upper eyelid. The change in noninvasive tear breakup time (BUT), Ocular Surface Disease Index (OSDI) questionnaire, patient satisfaction, and adverse events were measured and recorded at each visit, before each treatment. Results: The dry eye symptoms of the patients in both groups improved. The patients in group B had better recovery than those in group A: BUT (right eye: 11.6 ± 3.67 sec vs. 7.73 ± 1.99 sec; left eye: 12.73 ± 4.19 sec vs. 7.73 ± 1.40 sec), OSDI (8.87 ± 4.31 vs. 14.93 ± 3.47); patient satisfaction in group B remained good, but decreased in group A with prolonged treatment duration. No serious skin and eye complications were found in any patient. Conclusions: This study showed the patients who received IPL treatment on the upper eyelid experienced improved symptoms of MGD. A further long-term study should be conducted to increase our understanding of the effect of expanded IPL treatment.

Assessment of renal fibrosis in murine diabetic nephropathy using quantitative magnetization transfer MRI.

PURPOSE: Renal fibrosis is a hallmark of progressive renal disease; however, current clinical tests are insufficient for assessing renal fibrosis. Here we evaluated the utility of quantitative magnetization transfer MRI in detecting renal fibrosis in a murine model of progressive diabetic nephropathy (DN). METHODS: The db/db eNOS-/- mice, a well-recognized model of progressive DN, and normal wild-type mice were imaged at 7T. The quantitative magnetization transfer data were collected in coronal plane using a 2D magnetization transfer prepared spoiled gradient echo sequence with a Gaussian-shaped presaturation pulse. Parameters were derived using a two-pool fitting model. A normal range of cortical pool size ratio (PSR) was defined as Mean±2SD of wild-type kidneys (N = 20). The cortical regions whose PSR values exceeded this threshold (threshold PSR) were assessed. The correlations between the PSR-based and histological (collagen IV or picrosirius red stain) fibrosis measurements were evaluated. RESULTS: Compared with wild-type mice, moderate increases in mean PSR values and scattered clusters of high PSR region were observed in cortex of DN mouse kidneys. Abnormally high PSR regions (% area) that were detected by the threshold PSR were significantly increased in renal cortexes of DN mice. These regions progressively increased on aging and highly correlated with histological fibrosis measures, while the mean PSR values correlated much less. CONCLUSION: Renal fibrosis in DN can be assessed by the quantitative magnetization transfer MRI and threshold analysis. This technique may be used as a novel imaging biomarker for DN and other renal diseases.

Epidemiology of pediatric ocular trauma in the Chaoshan Region, China, 2001-2010.

BACKGROUND: Ocular trauma is the leading cause of monocular visual disability and noncongenital unilateral blindness in children. This study describes the epidemiology and medical care associated with nonfatal pediatric (≤ 17 years of age) eye injury-related hospitalization in the largest industrial base for plastic toy production in China. METHODS: A population-based retrospective study of patients hospitalized for ocular and orbital trauma in the ophthalmology departments of 3 major tertiary hospitals from 1st January 2001 to 31st December 2010 was performed. RESULTS: The study included 1035 injured eyes from 1018 patients over a 10-year period: 560 (54.1%) eyes exhibited open globe injuries, 402 (38.8%) eyes suffered closed globe injuries, 10 (1.0%) eyes suffered chemical injuries and 8 (0.8%) eyes exhibited thermal injuries, representing an average annual hospitalization rate of 0.37 per 10,000 (95% confidence interval [CI], 0.36-0.38) due to pediatric eye injury in the Chaoshan region. The mean patient age was 9.2 ± 4.4 years with a male-to-female ratio of 3.3:1 (P = 0.007). Children aged 6 to 11 years accounted for the highest percentage (40.8%, 416/1018) of hospitalization, 56.7% (236/416) of whom were hospitalized for open globe wounds. Injury occurred most frequently at home (73.1%). Open globe wounds cost the single most expensive financial burden (60.8%) of total charges with $998 ± 702 mean charges per hospitalization. CONCLUSIONS: Open globe wounds occurred at home are earmarked for the priorities to prevention strategies. Higher public awareness of protecting primary schoolchildren from home-related eye injuries should be strengthened urgently by legislation or regulation since the traditional industrial mode seems to remain the pattern for the foreseeable future. Further research that provide detailed information on the specific inciting agents of pediatric eye injuries are recommended for facilitating the development and targeting of appropriate injury prevention initiatives.

Randomized, controlled trial of an educational intervention to promote spectacle use in rural China: the see well to learn well study.

OBJECTIVE: To test an educational intervention promoting the purchase of spectacles among Chinese children. DESIGN: Randomized, controlled trial. PARTICIPANTS: Children in years 1 and 2 of all 20 junior and senior high schools (ages 12-17 years) in 3 rural townships in Guangdong, China. METHODS: Children underwent visual acuity (VA) testing, and parents of participants with presenting VA worse than 6/12 in either eye improving by more than 2 lines with cycloplegic refraction were recommended to purchase glasses. Children at 10 randomly selected schools received a lecture, video, and classroom demonstration promoting spectacle purchase. MAIN OUTCOME MEASURES: Self-reported purchase of spectacles (primary outcome) and observed wear or possession of newly purchased glasses (secondary outcome) at follow-up examinations (mean, 219 ± 87 days after the baseline visit). RESULTS: Among 15 404 eligible children, examinations were completed for 6379 (74.6%) at intervention schools and 5044 (73.6%) at control schools. Spectacles were recommended for 2236 (35.1%) children at intervention schools and for 2212 (43.9%) at control schools. Of these, 417 (25.7%) intervention schools children and 537 (34.0%, P = 0.45) control schools children reported buying glasses. Predictors of purchase in regression models included female gender (P = 0.02), worse uncorrected VA (P < 0.001), and higher absolute value of refractive error (P = 0.001). Neither the rate of self-reported purchase of glasses or observed wear or possession of newly purchased glasses differed between control schools and intervention schools in mixed-effect logistic regression models. Among children not purchasing glasses, 21.7% had better-eye VA of worse than 6/18. CONCLUSIONS: An intervention based on extensive pilot testing and focus groups in the area failed to promote spectacle purchase or wear. The high burden of remaining uncorrected poor vision underscores the need to develop better interventions. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Understanding barriers to cataract surgery among older persons in rural China through focus groups.

PURPOSE: To utilize focus groups (FGs) to identify barriers to cataract surgery specific to older persons in rural Guangdong, China. METHODS: Three focus groups in separate locations were carried out for persons aged 60 years and above with best-corrected vision <= 6/18 due to cataract, either accepting or refusing surgery. Participants also ranked responses to questions about acceptance of surgery among the elderly. FG transcripts were coded independently by two investigators using qualitative data management software. RESULTS: Twenty participants had a mean age of 72.7 ± 6.1 years, 14 (70.0%) were women and 17 (85.0%) were blind (best-corrected vision <= 6/60) in at least one eye. Cost was ranked by two of three groups as the main barrier to surgery, and all groups listed reducing cost as the best strategy to increase surgical uptake. Many respondents planned to use China's New Cooperative Medical Scheme (NCMS) health insurance to pay for surgery. Participants showed poor understanding of cataract, but ranked educational interventions low as methods of increasing uptake. Though opinions of local service quality were poor, respondents did not see quality as an important barrier to accepting service. Participants frequently depended on family members to pay for surgery. CONCLUSIONS: Contrary to some previous reports, cost may be an important barrier to cataract surgery in rural China, which NCMS may help to alleviate. Educational interventions to increase knowledge about cataract are needed, but may face skepticism among patients. Strategies to promote cataract surgery should target the entire family.

Attitudes of students, parents, and teachers toward glasses use in rural China.

OBJECTIVE: To use focus groups to understand barriers to glasses use among children in rural China. METHODS: Separate focus groups were conducted between December 17, 2007, and August 5, 2008, for the following 3 groups at each of 3 schools in rural China: children aged 14 to 18 years with myopia of less than -0.5 diopters in both eyes, those children's parents, and those children's teachers. Participants were also asked to rank their responses to questions about glasses use. The focus group transcripts were coded independently by 2 investigators using qualitative data management software. RESULTS: Respondents of all 3 types indicated that glasses purchase and wear should be delayed in children with early myopia and might be harmful to the eyes. Parents and students reported being uncertain about children's actual myopia status and whether glasses should be worn. Parents ranked their most common reason for not buying glasses as being "too busy with work," whereas "too expensive" ranked low. Inconvenience was ranked as an important reason for not wearing glasses among all 3 student groups. "Accuracy of lens power" was the first-ranked requirement for glasses among all student groups, whereas "new and attractive styles" was ranked last by all. All 3 types of respondents believed that wearing glasses or failing to wear them might worsen myopia. CONCLUSIONS: Educational programs are needed to address significant knowledge gaps in families and schools about glasses use in rural China. Cost and the need for attractive styles may not be significant barriers to use in this setting, raising the possibility of paying for such programs through cost recovery.

Population density and refractive error among Chinese children.

PURPOSE: China is urbanizing rapidly, and the prevalence of myopia is high. This study was conducted to identify the reasons for observed differences in the prevalence of myopia among urban versus rural Chinese children. METHODS: All children with uncorrected acuity of 6/12 or worse and a 50% random sample of children with vision better than 6/12 at all secondary schools in mixed rural-urban Liangying Township, Guangdong, underwent cycloplegic refraction, and provided data on age, gender, parental education, weekly near work and time outdoors, and urban development level of respondents' neighborhoods (12-item questionnaire). Population density of 32 villages and urban zones in Liangying was calculated from census figures (mean population density, 217 persons/km(2); range, 94-957; mean for Guangdong, 486). RESULTS: Among 5844 eligible children, 4612 (78.9%) had parental consent and completed examinations; 2957 were refracted per protocol, and 2480 (83.9%) of these had questionnaire data. Those with completed examinations were more likely to be girls (P < 0.001), and questionnaire respondents were more myopic (P = 0.02), but otherwise did not differ significantly from nonrespondents. In multivariate models, older age (P < 0.001), more near work (P = 0.02), and higher population density (P = 0.003), but not development index, parental education, or time outdoors were significantly associated with more myopic refractive error. CONCLUSIONS: Higher population density appears to be associated with myopia risk, independent of academic activity, time spent outdoors, familial educational level, or economic development, factors that have been thought to explain higher myopia prevalence among urban children. Mechanisms for this apparent association should be sought.

Impact of cataract screening outreach in rural China.

PURPOSE: To examine differences between patients with cataract detected during screening and presenting to clinic in rural China. METHODS: Subjects were recruited from 27 screenings and an eye clinic in the same town. All had pinhole-corrected vision < or =6/18 in > or =1 eye due to ophthalmologist-diagnosed cataract. Subjects were administered a previously validated questionnaire on barriers to surgery in four areas: knowledge (K), perceptions of quality (Q), transportation (T), and cost (C). RESULTS: Screening group (SG; n = 120) and clinic group (CG; n = 120) participants did not differ from eligible, examined screening and clinic patients respectively in age, gender, or vision. SG participants were significantly more likely to be female (P = 0.002) and had a smaller housing area and less education (P < 0.001 for both) than those in the CG. Those in the CG were more likely to be blind (habitual VA < or = 6/60) in the better-seeing eye (P = 0.05) and more willing to undergo and pay for cataract surgery (P < 0.001 for both) than SG. In logistic regression models, SG subjects had significantly lower quality scores (P < 0.001) and better habitual vision (P = 0.02) than did CG participants, and SG subjects who agreed to cataract surgery (78.3%) had significantly higher knowledge scores (P < 0.001) than those who refused. DISCUSSION: Screening outreach has the potential to ameliorate disparities in access to cataract surgery in rural China, as it appears more likely to detect patients with cataract with gender-related, economic, educational, and attitudinal barriers to surgery. However, education may be needed to convince screening subjects to undergo surgery.

Spectacle acceptance among secondary school students in rural China: the Xichang Pediatric Refractive Error Study (X-PRES)--report 5.

PURPOSE: To assess determinants of spectacle acceptance and use among rural Chinese children. METHODS: Children with uncorrected acuity < or = 6/12 in either eye and whose presenting vision could be improved > or = 2 lines with refraction were identified from a school-based sample of 1892 students. Information on obtaining glasses and the benefits of spectacles was provided to children, families, and teachers. Purchase of new spectacles and reasons for nonpurchase were assessed by direct inspection and interview 3 months later. RESULTS: Among 674 (35.6%) children requiring spectacles (mean age, 14.7 +/- 0.8 years), 597 (88.6%) were followed up. Among 339 children with no glasses at baseline, 30.7% purchased spectacles, whereas 43.2% of 258 children with inaccurate glasses replaced them. Most (70%) subjects paid US$13 to $26. Among children with bilateral vision < or = 6/18, 45.6% bought glasses. In multivariate models, presenting vision < 6/12 (P < 0.009), refractive error < -2.0 D (P < 0.001), and amount willing to pay for glasses (P = 0.01) were predictors of purchase. Reasons for nonpurchase included satisfaction with current vision (78% of those with glasses at baseline, 49% of those without), concerns over price or parental refusal (18%), and fear glasses would weaken the eyes (13%). Only 26% of children stated that they usually wore their new glasses. CONCLUSIONS: Many families in rural China will pay for glasses, though spectacle acceptance was < 50%, even among children with poor vision. Acceptance could be improved by price reduction, education showing that glasses will not harm the eyes, and parent-focused interventions.