Vision Care
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Although eyeglasses have been considered a cost-effective way to combat myopia, the empirical evidence of its impacts on improving learning outcomes is inconsistent. This paper provides empirical evidence examining the effect of providing eyeglasses on academic performance between provinces with a different economic level in western China. Overall, we find a significant impact in Intention-to-Treat analysis and a large and significant local average treatment effect of providing free eyeglasses to students in the poor province but not in the other. The difference in impact between the two provinces is not a matter of experimental design, implementation, or partial compliance. Instead, we find that the lack of impact in the wealthier provinces is mainly due to less blackboard usage in class and wealthier households. Our study found that providing free eyeglasses to disadvantaged groups boosted their academic performance more than to their counterparts.

Authors
Huan Wang
Yue Ma
Scott Rozelle
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Background

In rural China, children’s vision problems are very common, with many who would benefit from refractive correction not getting the care they need. This study examines whether a health information campaign that involves vision health education and a free trial of health product with free eyeglasses is effective at raising students’ awareness of myopia and promoting students’ eyeglasses usage.

Methods

We conducted an in-the-field randomized controlled experiment of a program providing vision health education and subsidized free eyeglasses to myopic children from 168 primary schools in rural Northwestern China in 2012.

Results

A total of 2189 students, mean age 10.5 years (49.3% male), participated in the baseline survey. At the baseline, the average correct response rate for visual knowledge among the sample students was 30.1%, and only 15% who needed eyeglasses used them. Seven months after intervention, the average correct response rate for vision knowledge were 48.5% and 48.3% in the education group and the education plus free eyeglasses group respectively, significantly higher than that of the control group. The rate of eyeglasses usage was 36% and 43% in the free eyeglasses group and the education plus free eyeglasses group respectively, significantly higher than that of the control group. The rate of eyeglasses compliance in the free eyeglasses group and the education plus free eyeglasses group was 19% and 26%, which also were significantly higher than the control group.

Conclusion

The information campaign combined with subsidized eyeglasses had a better effect both on vision knowledge and eyeglasses usage. The information campaign improved knowledge by providing the right information, and free eyeglasses changed the perceived utility and experience by the students using the product and getting benefits. Information and the free eyeglasses (subsidized) are complements.

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Risk Management and Healthcare Policy
Authors
Huan Wang
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Purpose: To determine the prevalence of visual impairment and glasses ownership among Han Chinese and Hui minority junior high school children in Ningxia Hui Autonomous Region, China. 

Design: Population-based cross-sectional study. 

Methods: Vision screening was conducted on 20,376 children (age 12–15 years) in all 124 rural junior high schools in Ningxia. Personal and family characteristics, glasses ownership, and academic performance were assessed through a survey questionnaire and standardized mathematics test, respectively. 

Results: The prevalence of visual acuity (VA) ≤6/12 in either eye was significantly higher among Han (54.5%) than Hui (45.2%) children (P<0.001), and was significantly positively associated with age, female sex, Han ethnicity, parental outmigration for work, shorter time spent outside during recess, shorter time spent watching television and higher time spent studying. Among children with VA≤6/12 in both eyes, only 56.8% of Han and 41.5% of Hui children had glasses (P<0.001). Glasses ownership was significantly associated with worse vision, greater family wealth, female sex, higher test scores, age, parental outmigration for work, understanding of myopia and glasses, higher time spent studying and Han ethnicity. 

Conclusion: One of the first of its kind, this report on Han and Hui ethnic schoolchildren confirms a high prevalence of visual impairment among both populations, but slightly higher among the Han. Both groups, especially the Hui, have low rates of glasses ownership. Future interventions and policies designed to improve glasses usage should focus on populations with lower incomes and seek to correct erroneous beliefs about the safety of glasses and efficacy of traditional eye exercises.

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PLOS ONE
Authors
Huan Wang
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Providing vision care to students in rural areas may serve the purpose of poverty alleviation by improving education and health. This study aims to provide a comprehensive review of myopia studies among rural students in China and offer policy recommendations for the national myopia prevention and control plan under “Targeted poverty alleviation through education”. The results show that in rural China, 25% of primary school students and 50% of lower secondary school students are myopic. Moreover, more than 70% of rural myopic students suffer from uncorrected vision, which negatively affects student academic performance and mental health. Correcting myopia also has a significant positive impact on student academic achievement. Studies show that vision screening is an effective way to identify myopia among rural students. Providing subsidies for the families of myopic students to obtain eyeglasses, and providing incentives to teachers, can significantly improve the uptake and usage rates of eyeglasses. A county hospital-based vision center may be an effective platform for reducing children's visual impairment in rural China.

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Journal of East China Normal University
Authors
Huan Wang
Scott Rozelle
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Background
To assess the prevalence of visual impairment and rate of wearing spectacles in schools for children of migrant workers in Shanghai, China.

Methods
Children from grade 1 to 5 in schools for children of migrant workers were randomly chosen for ocular examinations. All children were screened for uncorrected visual acuity and presenting visual acuity. After screening, the children whose uncorrected visual acuity was 20/40 or less received ocular motility evaluation, cycloplegic refraction/non-cycloplegic refraction, and external eye, anterior segment, media, and fundus examinations.

Results
A total of 9673 children were enumerated and 9512 (98.34%) participated in this study. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye were 13.33%, 11.26%, and 0.63%, respectively. The rate of wearing spectacles of the children with visual impairment in one or both eyes was 15.50%. Of these, 26.05% were wearing spectacles with inaccurate prescriptions. Refractive error was a major cause of visual impairment, accounting for 89.48% of all the visual impairment causes. Other causes of visual impairment included amblyopia accounting for 10.12%; congenital cataract, 0.1%; congenital nystagmus, 0.1%; ocular prosthesis, 0.1%; macular degeneration, 0.05%; and opaque cornea, 0.05%.

Conclusions
This is the first study of the prevalence and causes of visual impairment in schools for children of migrant workers in Shanghai, China. The visual impairment rate in schools for children of migrant workers in suburbs of Shanghai in the best eye before vision correction was lower than those of urban children in mainstream schools in Guangzhou in 2012, and higher than students in rural of Beijing in 1998 and in suburb of Chongqing in 2007. The refractive error was the principal cause of the visual impairment of the children of migrant workers. The rate of wearing spectacles was low and the percentage of inaccurate prescriptions, among those who wore spectacles, was high. Uncorrected refractive error was a significant cause of visual impairment in migrant children.

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BMC Public Health
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Background: Various types of near work have been suggested to promote the incidence and progression of myopia, while outdoor activity appears to prevent or retard myopia. However, there is a lack of consensus on how to interpret these results and translate them into effective intervention strategies. This study examined the association between visual acuity and time allocated to various activities among school-going children.
Methods: Population-based survey of 19,934 students in grade 4 and 5 from 252 randomly selected rural primary schools in Northwest China in September 2012. This survey measured visual acuity and collected self-reported data on time spent outdoors and time spent doing various types of near activities.
Results:  Prolonged (>60 minutes/day) computer usage (-0.025 LogMAR units, P = .011) and smartphone usage (-0.041 LogMAR units, P = .001) were significantly associated with greater refractive error, while television viewing and after-school study were not. For time spent outdoors, only time around midday was significantly associated with better uncorrected visual acuity. Compared to children who reported no midday time outdoors, those who spent time outdoors at midday for 31–60 minutes or more than 60 minutes had better uncorrected visual acuity by 0.016 LogMAR units (P = .014) and 0.016 units (P = .042), respectively.
Conclusions: Use of smart phones and computers were associated with declines in children’s vision, while television viewing was not. Statistically significant associations between outdoor time at midday and reduced myopia may support the hypothesis that light intensity plays a role in the protective effects of outdoor time.

 

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PLoS ONe
Authors
Huan Wang
Matthew Boswell
Scott Rozelle
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Can a county-based vision center increase eyeglasses use and improve school performance among primary schoolchildren in rural China? This cluster randomized clinical trial of 31 schools and 2613 participants showed that children who received eyeglasses earlier in the school year performed significantly better on an end-of-year mathematics test than children who received eyeglasses later in the year, equivalent to half a semester. Provision of free eyeglasses also improved children's use of spectacles.

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JAMA Ophthalmology
Authors
Yue Ma
Alexis Medina
Matthew Boswell
Scott Rozelle
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Abstract: More than 60 million children in rural China are “left-behind”—both parents live and work far from their rural homes and leave their children behind. This paper explores differences in how left-behind and non-left-behind children seek health remediation in China’s vast but understudied rural areas. This study examines this question in the context of a program to provide vision health care to myopic rural students. The data come from a randomized controlled trial of 13,100 students in Gansu and Shaanxi provinces in China. The results show that without a subsidy, uptake of health care services is low, even if individuals are provided with evidence of a potential problem (an eyeglasses prescription). Uptake rises two to three times when this information is paired with a subsidy voucher redeemable for a free pair of prescription eyeglasses. In fact, left-behind children who receive an eyeglasses voucher are not only more likely to redeem it, but also more likely to use the eyeglasses both in the short term and long term. In other words, in terms of uptake of care and compliance with treatment, the voucher program benefitted left-behind students more than non-left-behind students. The results provide a scientific understanding of differential impacts for guiding effective implementation of health policy to all groups in need in developing countries.

Keywords: randomized controlled trial; rural China; left-behind children; healthcare

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International Journal of Environmental Research and Public Health
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Huan Wang
Matthew Boswell
Scott Rozelle
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Currently available data on myopia and spectacle wear are drawn largely from China’s richer and middle-income areas, and little is known about refractive error and spectacle wear in the lowest income provinces. Studies from China and elsewhere suggest that large differences in myopia prevalence may exist between areas of different socioeconomic status within countries, but reasons for these differences are not well understood. The current report details the prevalence and predictors of myopia measured using the identical protocols and equipment in adjoining provinces of western China, middle-income Shaanxi and low-income Gansu. Study methods including institutional review board approvals and consent have been described elsewhere.

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Ophthalmology
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Scott Rozelle
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This paper examines the prevalence of vision problems and accessibility to and quality of vision care in rural China. We obtained data from 4 sources: 1) the National Rural Vision Care Survey; 2) the Private Optometrists Survey; 3) the County Hospital Eye Care Survey; and 4) the Rural School Vision Care Survey. The data from each of the surveys were collected by the authors during 2012. Thirty-three percent of the rural population surveyed self-reported vision problems. Twenty-two percent of subjects surveryed had ever had a vision exam. Among those who self-reported vision problems, 34% did not wear eyeglasses. Fifty-four percent of those with vision problems who had eyeglasses did not have a vision exam prior to receiving glasses. However, having a vision exam did not always guarantee access to quality vision care. Four channels of vision care service were assessed. The school vision examination program did not increase the usage rate of eyeglasses. Each county-hospital was staffed with three eye-doctors having one year of education beyond high school, serving more than 400,000 residents. Private optometrists often had low levels of education and professional certification. In conclusion, our findings shows that the vision care system in rural China is inadequate and ineffective in meeting the needs of the rural population sampled.

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Southeast Asian Journal of Tropical Medicine and Public Health
Authors
Matthew Boswell
Scott Rozelle
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